Contributors: Marc Hendricks, Alan Davidson, Harsha Lochan, Terry Schlaphoff, Shireen Maart

Transcription

1 Primary Immunodeficiency diseases (PIDs): diagnostic & treatment considerations for patients managed at Red Cross War Memorial Children s Hospital (RCWMCH) Lead author: Brian Eley: Brian.Eley@uct.ac.za Contributors: Marc Hendricks, Alan Davidson, Harsha Lochan, Terry Schlaphoff, Shireen Maart Posted: 7 August 2014 Summary This guideline describes the management of PIDs at RCWMCH. Diagnosis is constrained by a limited repertoire of tests offered through the National Health Laboratory Services (NHLS). Therapeutic options include haematopoietic stem cell transplantation in patients with severe immunodeficiency such as SCID. 1 P a g e

2 TABLE OF CONTENTS I. ABBREVIATIONS Page 3 II. ESTABLISHING A DIAGNOSIS Page 4 A. Clinical considerations Page 4 B. Laboratory considerations Page 8 1. HIV infection Page 8 2. Undifferentiated recurrent infection Page 8 3. Clinical presentation suggestive of a particular PID category Page 9 4. Chromosomal & genetic testing Page 12 C. Immunological consultation & investigation at RCWMCH Page 12 III. PATIENT RECORDS & PID DATABASE Page 13 IV. PREVENTION OF INFECTIONS & TREATMENT OF PIDS Page 14 A. Immunisation practice Page Routine immunization of children with PIDs Page Household contacts Page 15 B. Antimicrobial prophylaxis Page 15 C. Additional measures to control infections Page 16 D. Immunoglobulin replacement therapy Page Management of intravenous IRT Page Monthly IVIG infusions at RCWMCH Page 18 E. Haematopoietic stem cell transplantation Page Identification of a suitable donor Page Tissue typing procedure Page Pre-transplantation management Page Transplantation & post-transplantation management Page 22 F. Other therapeutic modalities Page 23 V. ONGOING CARE Page 23 VI. REFERENCES Page 25 VII. APPENDICES Page 26 2 P a g e

3 I. ABBREVIATIONS BCG CGD CMV CVID DTap-IPV/Hib EBV FMF GvHD HBV HIV HPV HSCT ID INH IRT IVIG LTI MMR NHLS OPV PCV PIDs RAG RCWMCH RV SABMR SCID SLE TB Td TMP-SMX VZIG WHIM syndrome XLA Bacillus Calmette Guérin Chronic granulomatous disease Cytomegalovirus Common variable immunodeficiency Diphtheria, tetanus, acellular pertussis, inactivated polio vaccine, Haemophilus influenza type B Epstein-Barr virus Familial Mediterranean Fever Graft versus host disease Hepatitis B vaccine Human immunodeficiency virus Human papillomavirus vaccine Haematopoietic stem cell transplantation Infectious diseases Isoniazid Immunoglobulin replacement therapy Intravenous immunoglobulin Laboratory for Tissue Immunology Measles, mumps, rubella vaccine National Health Laboratory Services Oral polio vaccine Pneumococcal conjugate vaccine Primary immunodeficiency diseases Recombination activation gene Red Cross War Memorial Children s Hospital Rotavirus vaccine South African Bone Marrow Registry Severe combined immunodeficiency Systemic lupus erythematosus Tuberculosis Tetanus and reduced amount of diphtheria vaccine Trimethoprim-sulphamethoxazole Varicella-zoster immunoglobulin Warts, hypogammaglobulinaemia, infections, myelokathexis syndrome X-linked agammaglobulinaemia 3 P a g e

4 II. ESTABLISHING A DIAGNOSIS A. Clinical considerations In the current international classification more than 200 specific PIDs are listed spanning nine major categories. These nine categories and disease examples within each category are included in table 1. For the complete international classification refer to reference 1. Because of limited diagnostic capacity only a small proportion of these PIDs can be diagnosed in South Africa. However, through international collaboration it may possible to confirm the diagnosis of a subset of patients by mutational analysis. This section focuses on the testing capability in our country. Table 1: The nine major categories of PIDs with specific disease examples PID category Combined (T and B cell) immunodeficiencies Combined immunodeficiencies with associated or syndromic features Predominantly antibody deficiencies Diseases of immune dysregulation Defects of phagocytic number, function, or both Defects in innate immunity Autoinflammatory disorders Complement deficiencies Phenocopies of PID Specific diseases (common examples) Severe combined immunodeficiency (SCID) Ataxia-telangiectasia DiGeorge syndrome Wiskott-Aldrich syndrome Hyper-IgE syndromes X-linked agammaglobulinaemia Common variable immunodeficiency Hyper-IgM syndromes IgA deficiency IgG subclass deficiency Specific antibody deficiency with normal immunoglobulin concentrations Transient hypogammaglobulinaemia of infancy Chediak-Higashi syndrome Familial haemophagocytic lymphohistiocytosis Lymphoproliferative syndromes e.g. X-linked lymphoproliferative syndrome Severe congenital neutropaenia Cyclic neutropaenia Leukocyte adhesion deficiency Shwachman-Diamond syndrome Chronic granulomatous disease IL-12p40 deficiency IFN- receptor 1 deficiency GATA2 deficiency IRAK-4 and MyD88 deficiencies WHIM syndrome TLR3 and UNC93B1 deficiencies Chronic mucocutaneous candidiasis Familial Mediterranean fever Hyper-IgD syndrome Muckle-Wells syndrome Familial cold autoinflammatory syndrome Deficiencies of components of the classic or alternate complement pathway e.g. C5 or C6 deficiency C1 inhibitor deficiency (a)phenocopies associated with somatic mutations e.g. Autoimmune lymphoproliferative syndrome (ALPS-SFAG) (b) Phenocopies associated with autoantibodies Chronic mucocutaneous candidiasis due to IL-17 4 P a g e

5 and/or IL-22 autoantibody Adult-onset immunodeficiency due to INF-gamma autoantibody Pulmonary alveolar proteinosis due to GM-CSF autoantibody A comprehensive clinical history and examination may identify socioeconomic factors, which increase susceptibility to infection, determine the pattern of infections, exclude secondary immunodeficiencies (Table 2), allergies and the crèche syndrome and direct the investigation of non-immunological causes of recurrent infection. Table 2: Common secondary immunodeficiencies Severe acute malnutrition Vitamin A deficiency HIV infection Measles Immunosuppresive therapy High-dose glucocorticosteroid administration Nephrotic syndrome Exposure to aero-pollutants Clinical evaluation may assist with the identification of specific PIDs such as combined immunodeficiencies associated with syndromic features and may direct the selection of appropriate laboratory investigations (Table 3). Table 3: Clinical features that may assist in the diagnosis of PIDs 2 Infection history Recurrent bacterial infection that is more frequent than expected for the patient s age More than one severe infection, e.g. meningitis, osteomyelitis, pneumonia, sepsis Infections that present atypically, are unusually severe or chronic, or fail regular treatment, especially if intravenous antibiotics are needed Abscess of an internal organ e.g. liver abscess Recurrent subcutaneous abscesses in children Prolonged or recurrent diarrhoea Any infection caused by an unexpected or opportunistic pathogen e.g. pneumonia caused by pneumocystis jerovecii in an HIV-unexposed child Severe or long-lasting warts, generalized molluscum contagiosum infection Extensive candidiasis, recurrent oral thrush in children >1 year Complications of vaccination such as disseminated BCG or varicella infection, paralytic polio or rotavirus infection Absence of evidence of secondary immunodeficiencies Family history PID in the family; familial occurrence of similar symptoms or recurrent 5 P a g e

6 infection (affected males related by the female line, or another clear pattern of inheritance) Unexplained early infant deaths, deaths due to infection Consanguinity in the (grand) parents (known or suspected) Autoimmune disease or haematological malignancy in several family members It is essential to construct a detailed family tree may suggest the Mendelian inheritance pattern and direct identification of the genetic defect. Other clinical features that could point to PID Aplasia or hypoplasia of thymus (X-ray) Angioedema Auto-immune disease, especially auto-immune cytopenias, SLE, non-specific arthritides Bleeding tendency Congenital cardiac anomalies, mainly conotruncal defects Chronic diarrhoea, malabsorption, pancreatic insufficiency Delayed separation of umbilical cord ( >4 weeks) Delayed shedding of primary teeth Developmental delay (progressive) Difficult-to-treat obstructive lung disease Eczema, dermatitis (severe, atypical) Failure to thrive Graft-versus-host reaction after blood transfusion, or mother-to-child (infant) engraftment Granulomas Haemolysis Hypersensitivity to sunlight Hypocalcaemic seizures Inflammatory bowel disease (atypical) Malignancy (mainly lymphoma) Non-allergic oedema Poor wound healing; scarring Recurrent fever Rib or other skeletal anomalies (X-ray) Thymoma Unexplained bronchiectasis, pneumatoceles, interstitial lung disease Vasculitis Physical examination Skin and appendages: abnormal hair or teeth; eczema; neonatal erythroderma; (partial) albinism; pale skin; incontinentia pigmenti; nail dystrophy; extensive warts or molluscae; congenital alopecia; vitiligo; petechiae (early onset, chronic); cold abscesses; telangiectasia; absence of sweating 6 P a g e

7 Oral cavity: gingivostomatitis (severe); periodontitis; aphthae (recurrent); giant oral ulcers; thrush; dental crowding; conical incisors; enamel hypoplasia; persistent deciduous teeth Eyes: retinal lesions; telangiectasia Lymphoid tissue: absence of lymph nodes and tonsils; lymphadenopathy (excessive); asplenia; organomegaly (liver, spleen) Neurological: ataxia; microcephaly; macrocephaly Other: angioedema (without urticaria); digital clubbing; dysmorphism; stunted growth or disproportional growth The PIDs usually manifest with one of eight clinical syndromes, defined in Table 4. Table 4: Clinical presentations and their associated PIDS (adapted from reference 2) Recurrent ENT and respiratory tract infection and/or bronchiectasis Most frequent PID category: Predominantly antibody deficiencies Other PID categories associated with this presentation:- - Combined immunodeficiencies - Combined immunodeficiencies with syndromic features - Defects of phagocyte number and/or function - Defects of innate immunity - Complement deficiencies Failure to thrive during infancy associated with intractable diarrhoea and severe eczema Most frequent PID category: Combined immunodeficiencies Other PID categories associated with this presentation:- - Combined immunodeficiencies with syndromic features - Defects of phagocyte number and/or function - Diseases of immune dysregulation - Defects of innate immunity Recurrent pyogenic infection with or without poor wound healing Most frequent PID category: Defects of phagocyte number and/or function Other PID categories associated with this presentation:- - Combined immunodeficiencies with syndromic features - Defects of innate immunity - Complement deficiencies Unusual infections or unusually severe clinical course of infections PID categories associated with this presentation:- - Combined immunodeficiencies - Combined immunodeficiencies with syndromic features - Diseases of immune dysregulation - Defects in innate immunity Recurrent infection caused by the same pathogen PID categories associated with this presentation:- - Combined immunodeficiencies with syndromic features - Defects of phagocyte number and/or function - Defects in innate immunity - Complement deficiencies Autoimmune or chronic inflammatory disease; or lymphoproliferative disorder Most frequent PID category:- diseases of immune dysregulation Other PID categories associated with this presentation:- - Combined immunodeficiencies - Predominantly antibody deficiencies - Combined immunodeficiencies with syndromic features - Defects of phagocyte number and/or function - Autoinflammatory disorders - Complement deficiencies 7 P a g e

8 Characteristic combinations of clinical features (eponymous syndromes) Specific diseases within most PID categories may be associated with this presentation Angioedema PID associated with this presentation: C1 inhibitor deficiency Furthermore, the spectrum of infections that a patient experiences may on occasion indicate the most likely PID category Table 5: spectrum of infections Predominantly antibody deficiencies: encapsulated bacteria e.g. S. pneumoniae, H. influenzae, mycoplasma, chronic enterovirus infections Cellular / combined immunodeficiencies: bacterial e.g. S. pneumoniae, H. influenza, S. aureus, viral e.g. CMV, fungal eg. Candida species, Histoplasmosis sp, and protozoal e.g. Pneumocystis jiroveci infections Defects of phagocyte number and/or function: catalase positive bacterial infections e.g. S. aureus, Burkholderia cepacia, Serratia marcescens, Nocardia sp. E. coli, Ps. Aeruginosa, M. tuberculosis (particularly in high prevalence settings), Nontuberculous mycobacterial and BCG and fungal infections e.g. Aspergillus fumigatus Early complement deficiencies: encapsulated bacterial infections Terminal C deficiencies (C5-C9) & properdin deficiency: recurrent neisserial infections B. Laboratory considerations 1. HIV infection HIV infection is a significant problem in South Africa and may mimic many of the presentations of PIDs. It should be excluded before requesting other, expensive immunological investigations. 2. Undifferentiated recurrent infection Some patients with PIDs present with undifferentiated recurrent infection i.e. without a pattern of infections that is suggestive of a particular category of PIDs. These children should be subjected to a general immunological screen. This may be performed in a structured manner, guided by an experienced clinician or clinical immunologist. Table 6 provides a structured approach to the selection of immunological tests in these patients. General immunological screening should assist in the diagnosis of many PIDs (Tables 6 & 7). Table 6: A structured approach immunological testing in a patient with undifferentiated recurrent infection, adapted from an approach of the Jeffrey Modell Foundation 3 Step 1 History, Physical examination, Mass and height Exclude HIV Infection Full blood count and differential count Quantitative immunoglobulin levels (IgA, IgM, IgG, IgE) Step 2 Specific antibody production (tetanus and/or diphtheria, response to pneumococcal vaccine (pre- and post- titres, production of isohaemagglutinins 8 P a g e

9 IgG subclass analysis Step 3 Lymphocyte subsets (CD3, CD4, CD8, CD19, CD16/56) Complement screen (CH50 or CH100) Neutrophil oxidation burst (if indicated) Lymphocyte proliferation studies (using mitogen and antigen stimulation) Step 4 Advanced testing guided by an experienced clinician e.g. specific complement component screen including mutational screening for common C5 & C6 mutations Blood specimen collection from the index patient and immediate family members for mutational analysis together with completed consent forms for each individual providing specimens (discuss with duty ID senior registrar or consultant to arrange DNA extraction, storage and liaison with an external laboratory) Table 7: Immunological test may aid the diagnosis of many PIDs Immunological test Total lymphocyte count Eosinophil count Neutrophil count Granulocyte morphology Platelet count & size Immunoglobulins (IgM, IgA, IgG) IgE IgG subclasses Specific antibody production Lymphocyte subsets Lymphocyte proliferative responses Complement screen (CH50 or CH100) Alternative complement pathway screen (AH50 or AH100) [available in the private sector] Neutrophil oxidative burst test PIDs SCID Omenn syndrome Congenital neutropaenias Leukocyte adhesion deficiency (neutrophilia) Chediak-Higashi syndrome Wiskott-Aldrich syndrome (small platelets, thrombocytopaenia) XLA, CVID, IgA deficiency, hyper-igm syndromes, transient hypogammaglobulinaemia of infancy, combined T and B cell immunodeficiencies Hyper-IgE syndromes, combined T and B cell immunodeficiencies Isolated IgG subclass deficiency, IgA with IgG subclass deficiency Specific antibody deficiency with normal immunoglobulin concentrations XLA, autosomal recessive conditions causing B - hypogammaglobulinaemia, combined T and B cell immunodeficiencies including SCID Combined T and B cell immunodeficiencies Chronic mucocutaneous candidiasis (absent / reduced proliferation following stimulation with Candida antigen) Deficiencies in the classic complement pathway (C1 to C9) Deficiencies of properdin, factor B, factor D, factor I (leading to secondary C3 deficiency), C3 and C5 to C9 Chronic granulomatous disease 3. Clinical presentation suggestive of a particular PID category 4,5 Alternatively, the clinical presentation may suggest a particular PID category or a specific deficiency in which case a more focused investigative approach may be adopted as follows: 9 P a g e

10 Suspected combined (T and B cell) immunodeficiency: Analysis of white cell count and differential is an important first step in patients with suspected cellular deficiency. Total lymphocyte count in an infant persistently <3.0 x 10 9 /L is predictive of SCID, and therefore an indication for urgent lymphocyte subset analysis. However, using low lymphocyte count will not identify patients with Omenn syndrome who have normal or increased T-cell numbers due to oligoclonal expansion of T-cells. Circulating T-cells may also be identified in patients with SCID because of maternal T-cell engraftment. The next steps in the investigation of suspected cellular deficiency includes measurement of lymphocyte subsets and in vitro functional testing (lymphocyte proliferative studies). Lymphocyte subset analysis in infants suspected of having SCID helps to confirm the diagnosis and identify the potential genetic defect. A simplified classification of SCID based on the presence or absence of T-cells, B-cells and natural killer (NK)-cells is summarised in Table 8. Table 8: Interpretation of lymphocyte subset results: Classification of severe combined immunodeficiency (SCID) Immunological phenotype Disease Inheritance T-B+ SCID NK- Common γ-chain deficiency Janus kinase-3 deficiency XL AR NK+ T-B- SCID NK- NK+ IL-7 receptor α-chain deficiency CD45 deficiency CD3 /CD3 /CD3 deficiency Coronin-1A deficiency Adenosine deaminase deficiency Reticular dysgenesis RAG-1 / RAG-2 deficiency DCLRE1C (Artemis) deficiency Adenosine deaminase deficiency DNA PKcs deficiency Cerunnos deficiency AR AR AR AR AR AR AR AR AR AR AR RAG=recombination activation gene, DNA PKcs deficiency = DNA-dependant protein kinase Catalytic subunit deficiency, DCLRE1C deficiency = DNA cross-link repair 1C deficiency Suspected predominantly antibody deficiencies: Initial screening includes measurement of IgG, IGM and IgA concentrations, and a comparison of these results with normal age-related reference ranges. Quantitation of IgG subclass concentration is most useful in the evaluation of patients with IgA deficiency with recurrent bacterial infection. Measurement of specific antibody production is useful for confirming defective antibody production, and is essential when total immunoglobulin concentrations are only moderately reduced or normal in patients with recurrent bacterial infection. The easiest method is the evaluation of spontaneously produced anti-blood group antibodies (isohaemagglutinins) and specific antibodies generated in response to routine childhood immunisation. Isohaemagglutinin titres may be measured at local blood banks. Titres 1 in 8 to A 1 and B cells are usually present in normal individuals. Assessing in vivo antibody production involves immunising a patient with protein antigen (e.g. tetanus toxoid or diphtheria toxoid) and 10 P a g e

11 polysaccharide antigen (23-valent pneumococcal polysaccharide vaccine) and measuring pre-immunisation and 3-4 week post-immunisation antibody titres. In subjects with normal antibody production, a 4-fold increase in antibody concentration occurs. Responses to protein antigens fall within the IgG1 subclass. Response to polysaccharide antigens is located within the IgG2 subclass. Conjugate polysaccharide vaccines are not helpful in the functional evaluation of an IgG2 subclass deficiency or a selective polysaccharide antibody deficiency because the responses to conjugate vaccines fall within the IgG1 and IgG3 subclasses. Determining the presence or absence of B-cells in patients with panhypogammaglobulinaemia is important to identify patients with absent B-cells (B - hypogammaglobulinaemia), caused by arrest in early B-cell development. Approximately 85% of patients with this phenotype have XLA (formerly called Bruton agammaglobulinaemia). The remaining patients with this phenotype have one of several autosomal recessive gene defects. Advanced immunological testing requires specialised assays such as the detection of CD40 ligand expression by flow cytometry in patients with an immunoglobulin pattern consistent with CD40 ligand deficiency, and naïve and memory B-cell subset analysis for characterising patients with CVID. Few specialised investigations are currently available in South Africa. Table 9 provides guidance for diagnosing common antibody deficiencies. Table 9: Interpretation of immunoglobulin results: Major types of predominantly antibody deficiencies Disease B cells Immunoglobulins X-linked Absent /low Low IgG, IgA, IgM agammaglobulinaemia CVID > 1% Low IgG, IgA Normal / low IgM Hyper-IgM syndromes Normal Normal / raised IgM Low IgG, IgA Isolated IgG subclass deficiency Normal Normal Selective IgA deficiency Normal Low IgA Normal IgG, IgM Specific antibody deficiency Normal Normal CVID: Common variable immunodeficiency Suspected defects of phagocyte number or function: Screening starts with a review of the absolute neutrophil count and morphology. The diagnosis of cyclical neutropaenia requires serial measurement of the neutrophil count, two to three times per week for at least 4-6 weeks. A diagnosis of severe congenital neutropaenia is suggested with neutrophil counts persistently below 0.5 x 10 9 /L. Bone marrow biopsy is required to exclude a malignancy, another cause of neutropaenia or maturational arrest typical of severe congenital neutropaenia. In patients with LAD-1, mild to moderate neutrophilia is usually present in the absence of infection, and during acute infection marked granulocytosis with neutrophil counts reaching above 100 x 10 9 /L may be documented. In LAD-1 the absent expression of the adhesion molecules CD11 and CD18 may be established by flow cytometric assay. An abnormal neutrophil oxidative burst test occurs in CGD. Evaluation of chemotaxis and phagocytosis requires specialised investigations, which are not widely available. 11 P a g e

12 Suspected complement deficiencies: The best screening test for deficiencies in the classical complement pathway is the total haemolytic complement assay (CH50 or CH100). Deficiencies in the alternative complement pathway can be assessed using the AH50 assay. A decreased AH50 result suggests deficiency of factor B, factor D or properidin. Whereas decrease in both CH50 and AH50 results suggest a deficiency of one of the shared complement components, C3 to C9. A C1 esterase inhibitor assay is used to screen for enzyme deficiency, and the CH50 assay will be abnormal in C2 deficiency. Hyper-IgE and Hyper-IgD syndromes: A consistent feature of Job Syndrome is an elevated IgE concentration, typically >2000 IU/mL. Hyper-IgD Syndrome is caused by mutations in the mevalonate kinase gene. Approximately 80% of these patients have elevated plasma IgD concentrations. In the remaining 20% of patients, the IgD level is normal. However, other autoinflammatory disorders, such as FMF may be associated with an elevated IgD concentration. 4. Chromosomal and genetic testing Chromosomal analysis is important in children with suspected DiGeorge syndrome to determine the presence of 22q11.2 deletion and can be arranged through the Department of Human Genetics, UCT. Genetic analysis is required for a definitive diagnosis of most PIDs, but is not routinely available in South Africa. Genetic testing may occasionally be arranged through an externally based laboratory. Before genetic analysis can be arranged EDTA-preserved specimens are required, usually form the index patient and the parents. DNA extraction is currently performed in the 4 th floor ICH laboratory by special arrangement, consult with Professor Eley. A consent form (Appendix 1) must be completed on every individual submitting a specimen for genetic analysis. The original forms should be given to Professor Eley for safe-keeping. C. Immunological consultation & investigations at RCWMCH Several sub-specialist services contribute to the management of conditions listed in the latest international classification of PIDs. 1 For example, the haematology/oncology service (Professor A Davidson, Dr M Hendricks, Dr A van Eyssen) manages children with neutropaenic syndromes, some children with Wiskott-Aldrich syndrome, familial haematophagocytic lymphohistiocytosis, children with PIDs manifesting with oncological diseases and children with PIDs following HSCT. The rheumatology service directed by Dr C Scott manages all patients with autoinflammatory diseases. The Neurology service (Professor J Wilmshurst, Dr A Ndondo) manages children with Ataxia-telangiectasia. The cardiology service (Dr R de Dekker) manages children with cardiogenetic conditions such as DiGeorge syndrome. The pulmonology service (Dr M Zampoli, Dr A Vanker) manages children with pulmonary alveolar proteinosis. The Allergy service (Professor M Levin) manages children with C1 inhibitor deficiency and Professor Potter based in the Lung Institute, University of Cape Town currently manages terminal complement deficiencies. Adult patients with primary immunodeficiencies are managed by Professor Stanley Ress / Dr Jonny Peter at Groote Schuur Hospital. 12 P a g e

13 Role of the infectious diseases service: The infectious diseases service traditionally manages many children with PIDs who manifest with infectious disease problems as described in table 4. The duty senior registrar and consultant for the infectious diseases service (contact through the RCWMCH telephone exchange: ) share clinical responsibilities for immunology. Appointments for outpatient consultation can be arranged with the duty senior registrar or consultant immunology patients are seen on Monday mornings in A11, refer section V. Ongoing care on page 22 for more details about outpatient activities. Immunological investigation: Immune function tests are expensive. Therefore, requests for immunological investigation must be discussed with the duty senior registrar or Prof Eley. Thereafter, specific tests may be arranged with the NHLS chemical pathology service on extension: Specimens should ideally be sent to Specimen Reception before 09h30. The specimens are transported to Tygerberg Hospital where the tests are performed. Results are obtainable from the Chemical Pathology laboratory, RCWMCH or through the NHLS DISA website. Table 10: Specimen requirements Test name Immunoglobulin concentrations IgG subclass concentrations Specific IgG titres Lymphocyte subset analysis Oxidative burst test CH50 (Total haemolytic complement) Lymphocyte proliferative tests Leucocyte adhesion markers Specimen requirements 2-3 ml clotted tube 2-3 ml clotted tube 2-3 ml clotted blood 2-3 ml EDTA blood 2-3 ml heparinised blood 2-3 ml clotted blood on ice 2-3 ml EDTA blood 2-3 ml EDTA blood DNA extraction for mutational analysis: Generally 2-5 ml EDTA-preserved blood per subject is sufficient for DNA extraction. Blood specimens should be collected from the index patient and immediate family members together with completed consent forms for each individual providing a specimen. Discuss with ID senior registrar or consultant to arrange DNA extraction and storage, and liaison with an external laboratory. (2) Role of the Haematology / Oncology service: Some of the conditions listed in the latest international PID classification are managed with haematopoeitic stem cell transplant (HSCT). Once the need for HSCT has been established blood for HLA tissue typing should be sent from the patient and potential donors as a matter of urgency. Please discuss with the haematology/oncology consultant on call and the South African Bone Marrow Registry (see page 19). III. PATIENT RECORDS & PID DATABASE The ID service maintains a database of all children diagnosed or managed with PIDs at RCWMCH. Once a patient has been diagnosed with a PID, a datasheet (appendix 2) should be completed, usually by the ID senior registrar in collaboration with the referring doctor. The completed data sheets should be reviewed at the ad hoc Tuesday lunchtime Immunology meeting. Once the initial entry is complete, the data sheets should be given to Spasina King (extension number: 5821) who will enter the data into the electronic database. Datasheets may be accessed by clinicians 13 P a g e

14 attending to PID patients. Furthermore, therapeutic updates, complications and a change to the outcome should be entered on the data sheet when necessary. IV. PREVENTION OF INFECTION &TREATMENT OF PIDs Several strategies of preventing infection and treating children with PIDs including routine immunization practice, antimicrobial prophylaxis, immunoglobulin replacement therapy (IRT) and haematopoietic stem cell transplantation (HSCT). A. Immunisation practice 1. Routine immunisation of children with PIDs Currently, The South African EPI schedule recommends that the following vaccines be administered to all children. Table 11: South African EPI schedule Age of child Recommended vaccines At birth BCG, OPV (0) 6 weeks OPV (1), PCV (1), HBV (1), DTaP-IPV/Hib (1), RV (1) 10 weeks HBV (2), DTaP-IPV/Hib (1), RV (2) 14 weeks PCV (2), HBV (3), DTaP-IPV/Hib (3), RV (2) 9 months PCV (3), Measles vaccine (1) 18 months DTaP-IPV/Hib (4), Measles vaccine (2) 6 years Td (1) 9-12 years HPV x 2 doses, 6 months apart 12 years Td (2) The EPI programme also makes provision for the administration of annual inactivated influenza vaccine to high-risk patient groups. 6 In the private sector, MMR, Varicella, Hepatitis A vaccines and additional doses of inactivated pertussis-containing vaccine is recommended in older children. Immunisation with live viral or bacterial vaccines is known concern for individuals with serious PIDs of T-cell, B-cell and phagocytic cell origin. Recommendations for immunizing patients with PIDs have been formulated by the American Academy of Pediatrics and are summarized in table 12. Table 12: Immunisation of children with PIDs 7,8 Category/conditions Severe antibody deficiencies e.g. XLA & CVID Less severe antibody deficiencies e.g. IgA or IgG subclass deficiency Complete, cell-mediated deficiencies e.g. SCID, complete DiGeorge syndrome Vaccines contraindicated OPV, smallpox, LAIV, Yellow fever, most live bacterial vaccines; consider measles; there is no data for varicella or rotavirus vaccines OPV, other live vaccines appear to be safe All live vaccines Comments Effectiveness of any vaccine is uncertain if it depends only on humoral immunity e.g. PPSV23, MPSV4; IVIG interferes with measles and possibly varicella responses; Efficacy of pneumococcal vaccination is not documented in severe antibody deficiency; Consider measles & varicella vaccines Little vaccine-related viral infection is seen with CVID All vaccines probably effective; immune responses may be attenuated All vaccines are probably ineffective; immune response might be attenuated; pneumococcal and Hib vaccines are recommended 14 P a g e

15 Partial defects e.g. most patients with DiGeorge syndrome, Wiskott- Aldrich syndrome, Ataxia telangiectasia Selected live vaccines: BCG, Ty21a S. typhi vaccine, LAIV, MMR, varicella, herpes zoster, OPV, yellow fever, smallpox & rotavirus Effectiveness of any vaccine depends on degree of immune suppression; pneumococcal, Hib and meningococcal vaccines are recommended; consider Hib vaccine if not administered in infancy NB: Weight of evidence does not support strict avoidance of all live vaccines, particularly when the CD4 count is >500 cells/mm 3 Complement deficiencies None All routine vaccines are probably effective; pneumococcal and meningococcal vaccines recommended Phagocytic disorders e.g. CGD, leukocyte adhesion defects, myeloperoxidase deficiency Defects affecting the interferon-gamma IL- 12 pathway Live-bacterial vaccines i.e. BCG & Ty21a S. typhi vaccine Live mycobacterial vaccines, currently only BCG All inactivated vaccines and probably all live-virus vaccines are safe & effective There are no reported live attenuated viral vaccineinduced infection, but caution is urged There is very few data on live vaccines other than BCG Re-immunisation following HSCT is essential and should be directed by the transplant centre. This is addressed in section E, Haematopoietic stem cell transplantation and Appendix Household contacts 7,8 Immunocompetent close contacts of patients with compromised immunity should not receive smallpox vaccine or OPV because these vaccine viruses may be transmitted to immunocompromised individuals. Close contacts can receive other standard vaccines including MMR, rotavirus vaccine, varicella vaccine and measles vaccine because these pose little risk of infection to the immunocompromised individual. Varicella vaccine is recommended for susceptible contacts of immunocompromised patients because transmission of vaccine virus from healthy individuals is rare. No post-immunisation precautions are required unless the vaccine recipient develops a vesicular exanthema in this situation isolation of the immunocompromised patient and administration of VZIG is recommended, and the household contact should be treated with acyclovir. Annual immunization with inactivated influenza vaccine is recommended for all household contacts from 6 months of age onwards Scheduled periodic immunization of household contacts with pertussis vaccine (Tdap), pneumococcal vaccine, measles, mumps and rubella vaccine should proceed. B. Antimicrobial prophylaxis: Several PIDs may benefit from antimicrobial prophylaxis, including those with concomitant bronchiectasis (Table 13). In milder conditions (e.g. IgA deficiency and transient hypogammaglobulinaemia of infancy) recurrent infections may occasionally require short courses of prophylactic antibiotics. Antimicrobial prophylaxis may be added in patients with severe antibody 15 P a g e

16 deficiencies, if IRT is unable to adequately control the frequency of recurrent infections. Table 13: Oral antimicrobial prophylaxis for children with PIDs 9 Disease Severe combined immunodeficiency Common variable immunodeficiency where IRT is inadequate X-linked agammaglobulinaemia where IRT is inadequate DiGeorge syndrome Wiskott-Aldrich syndrome Ataxia-telangiectasia Job syndrome Chronic granulomatous disease Terminal complement (e.g. C5 or C6) deficiencies Regimen TMP-SMX 5mg/kg (of TMP) once daily Fluconazole 3mg/kg once daily Acyclovir 20mg/kg/dose, four times daily TMP-SMX 5mg/kg (of TMP) once daily, 3 days/week TMP-SMX 5mg/kg (of TMP) once daily, 3 days/week TMP-SMX 5mg/kg (of TMP) once daily, 3 days/week Fluconazole 3mg/kg once daily TMP-SMX 5mg/kg (of TMP) once daily, 3 days/week Fluconazole 3mg/kg once daily Acyclovir 20mg/kg/dose, four times daily Phenoxymethylpenicillin if splenectomy i.e. 125 mg twice daily (<5 years) or 250mg twice daily (>5 years) Azithromycin 10 mg/kg/day, 3 days/week TMP-SMX 5mg/kg (of TMP) once daily or Flucloxacillin mg twice daily If pneumatocoeles are present add Itraconazole 100mg daily (< 13 years or < 50kg) or 200mg daily ( 13 years or 50kg) TMP-SMX 5mg/kg (of TMP) once daily Itraconazole 100mg daily (< 13 years or < 50kg) or 200mg daily ( 13 years or 50kg) Phenoxymethylpenicillin125 mg twice daily (<5 years) or 250mg twice daily (>5 years) TMP/SMX = Trimethoprim-sulphamethoxazole C. Additional measures to control infections General advice aimed at reducing the risk of infection will benefit many immunodeficient patients and should include advice on personal, hand and dental hygiene, avoidance of exposure to individuals with active infections and the provision of annual influenza immunisation for household contacts. Furthermore, antimicrobial prophylaxis is often administered with other interventions to reduce the risk of infection. In SCID, prior to a HSCT, the patient should ideally be managed in a laminar flow facility, with full contact precautions, and receive sterile feeds. In the immediate post-hsct period similar management interventions apply. 16 P a g e

17 In CGD, life-long interferon-γ 50 μg/m 3 three times per week is recommended in combination with cotrimoxazole and itraconazole prophylaxis. However, high cost limits its use in South Africa. Job Syndrome, colonization and infection by Staphylocccus aureus may be prevented or controlled by regular bleach or chlorhexidine soaks i.e. bleach 120 ml per bath tub or chlorhexidine soaks three times per week and intermittent muporocin applications i.e. twice daily nasal applications for 5-10 days, repeat this prescription intermittently In addition to penicillin prophylaxis, meningococcal immunisation is recommended for patients with terminal complement deficiencies. D. Immunoglobulin Replacement Therapy (IRT) : Many antibody deficiencies and combined deficiencies, in which quantitative or qualitative IgG deficiency occurs may benefit from IRT (Table 11). Table 14: Immunodeficiencies that may benefit from IRT Predominantly antibody deficiencies X-linked agammaglobulinaemia Common variable immunodeficiency Hyper-IgM syndromes IgG subclass deficiency with/without IgA deficiency Specific antibody deficiency with normal immunoglobulin concentration (selected cases) Transient hypogammaglobulinaemia of infancy (selected cases) Combined T and B cell immunodeficiencies Severe combined immunodeficiency Wiskott-Aldrich syndrome Ataxia-telangiecatia with IgG or IgG subclass deficiency X-linked lymphoproliferative syndrome 1. Management of intravenous IRT Lifelong IRT is required for severe, genetically confirmed deficiencies, including conditions in which arrest in early B-cell development is demonstrated. Incompletely defined predominantly antibody deficiencies characterised by the presence of circulating B-cells and subnormal IgG concentration may require IRT for 1-5 years followed by re-evaluation of serum immunoglobulin concentrations since hypogammaglobulinaemia may be transient and resolve spontaneously. If IgG deficiency persists IRT should be restarted and may have to be continued indefinitely if it fails to resolve. IRT is not indicated for IgA Deficiency. Treatment with intravenous immunoglobulin (IVIG) is most widely used. Subcutaneous immunoglobulin administration is less frequently used but equally effective. Intravenous immunoglobulin is administered at 3-4 week intervals at the usual starting dose of 400 mg per kg for patients without chronic lung disease and 600 mg per kg for those with bronchiectasis. 17 P a g e

18 The mean half-life of IgG is days. After achieving steady state, an IgG trough concentration of >5g/L reduces the infection rate and trough levels up to 10g/L will progressively reduce the risk of pneumonia. Progressive adjustment of the total infusion dose is required to optimise the IgG trough concentration. In some children, IRT does not adequately control the underlying infectious disease risk and routine cotrimoxazole prophylaxis may be added (refer below, section B: antibiotic prophylaxis) When commencing an IVIG infusion, start at a rate of ml/kg/minute and if this is tolerated, gradually increase the rate to 0.1 ml/kg/minute. Infusions should be given under the same supervision and monitoring conditions that are required for blood transfusions. Adverse events: Anaphylactic reactions are extremely rare but have been described in IgA-deficient patients with circulating anti-iga antibodies. Most IVIG reactions are non-anaphylactoid, typically manifesting with nausea, chills, headache, backache, malaise, fever, pruritis, and/or tingling. Reactions occur in 5-15% of patients receiving IVIG and are mainly related to the rate of infusion. Slowing or stopping the infusion for minutes will reverse most reactions. Recurring side effects can be modified or prevented by administering aspirin (15 mg/kg/dose, orally) ibuprofen (5 mg/kg/dose, orally) or hydrocortisone (6 mg/kg/dose, IV, maximum 100 mg) one hour before an IVIG infusion. There is no risk of HIV or hepatitis B transmission. Some immunoglobulin preparations have been associated with outbreaks of non-a, non-b hepatitis, including hepatitis C. In children receiving long-term IVIG, alanine aminotransferase (ALT) levels should be monitored at 3-6 monthly intervals to detect subclinical transmitted hepatitis. 2. Monthly IVIG infusions at RCWMCH: Intravenous immunoglobulin infusions are administered in the 'Day room' in ward E2, usually on Friday mornings. To make a booking contact the ward sister, extension: 5053 or All children managed through the immunology service should be discussed with a senior registrar or immunology consultant to ensure continuity of care. E. Haematopoietic stem cell transplantation (HSCT) HSCT is the treatment of choice of severe immunodeficiencies (Table 13). Table 13: Indications for HSCT 12 Severe combined immunodeficiency (SCID): refer table 8 for the spectrum of SCID diseases Other combined immunodeficiencies (CID) including Omenn s syndrome, Adenosine deaminase deficiency, purine nucleoside phosphorylase deficiency, MCH class II deficiency, CD40 ligand deficiency & CD40 deficiency Combined immunodeficiencies with associated or syndromic features such as Wiskott-Aldrich syndrome & DiGeorge syndrome Phagocytic disorders including Kostmann agranulocytosis, severe congenital neutropaenia, chronic granulomatous disease, leukocyte adhesion deficiency type I, 18 P a g e

19 & IFN-gamma receptor deficiency type I Diseases of immune dysregulation such as X-linked lymphoproliferative syndrome, familial haemophagocytic lymphohistiocytosis, Chediak-Hugashi syndrome & Griselli syndrome 1. Identification of a suitable donor, e.g. sibling, haplo-identical parent / sibling, other related donor e.g. cousin, matched unrelated donor: Patients who may benefit from HSCT should be discussed with immunology service or haematology/oncology service at the earliest opportunity. Once there is agreement that a child may benefit from HSCT i.e. agreement by the haematology/oncology service at RCWMCH, the referral doctor and the parents, a suitable donor should be sought. Please note: Tissue typing should be arranged in consultation with the haematology/oncology service at RCWMCH. This is done through NHLS Laboratory for Tissue Immunology (LTI) in Cape Town. First tissue type all siblings to determine whether a matched related donor can be identified. The chance of finding a suitable HLA-identical donor among the siblings ranges from 15-20%. If there are no siblings or if there is no suitable sibling donor blood specimens may be requested from the parents to determine whether they would be suitable HLAnonidentical donors. Testing of the extended family to identify a potential cousin donor could also be considered. If a matched unrelated donor (MUD) is considered, the South African Bone Marrow Registry (SABMR) can be approached to search for a suitable donor. To request a MUD search, the Preliminary Search Request Form (Appendix 4) must be submitted to the SABMR together with the HLA typing of the patient and any family members who were HLA typed. Please note: The SABMR and LTI are separate entities. The SABMR has a purely administrative role but works very closely with LTI as the laboratory of choice for HLA typing for the matched unrelated donor programme. This is because of its international accreditation. The patient must have been HLA-A, -B and -DRB1 DNA typed for a basic MUD search report to be generated. Based on the preliminary search results, it is the treating physician s decision whether the search proceeds to active testing of donors ( search activation ). Before search activation, the patient should ideally be HLA typed at High Resolution at the HLA-A, -B, -C, -DRB1 and -DQB1 loci. The SABMR will, at any stage of the search, guide the treating physician / transplant centre regarding the next steps, including additional testing of patient and potential donors. The search for a suitable donor could be extended to International Bone Marrow registries if private funding or medical aid support is available. 19 P a g e

20 Extent of the search and timelines Ms Terry Schlaphoff or Ms Veronica Borrill at the SABMR can be contacted to arrange the donor search. Tissue typing of unrelated donors may take at least 3-4 weeks to be completed. If the search for a suitable donor is extended beyond South Africa, more time may be required to find a suitable donor. From preliminary search to transplantation with an unrelated donor, may take from 2 6 months. South African Bone Marrow Registry Physical Address: Postal Address: J57 Old Outpatients Building SABMR Groote Schuur Hospital PO Box Observatory Mowbray Cape Town Cape Town Tissue typing procedure The following blood specimens are required from the patient: and potential donors for HLA typing: 1 x 10ml Clotted (Red Top) 7 x 5ml EDTA (Purple Top) For paediatric patients, the volume of blood required will depend on the patient s total nucleated cell count (TNC). Usually 5-10 ml of EDTApreserved blood is required from a young child and about 15 ml of EDTApreserved blood from the siblings. However, the TNC is used to determine the required blood volume to ensure that enough DNA is obtained from the blood specimen. Please contact the laboratory to discuss the optimal blood volumes. Specimens together with the completed request form (Appendix 5) should be sent to: NHLS Laboratory for Tissue Immunology C17 Specimen Reception Groote Schuur Hospital Laboratory contact number: All specimens must reach the laboratory within 24 hours of having been taken. Specimens that are transported to the laboratory using a courier service must be properly packaged to avoid breakage while in transit. Please store and transport the specimens at room temperature. (22 C) Ensure that all tubes are correctly labelled and that a request form (Appendix 5) has been properly completed. 20 P a g e

21 Please inform the laboratory telephonically when specimens are expected to arrive in the tissue immunology laboratory. 3. Pre-transplantation management 12,13 Please note: The following recommendations focus on the pre-transplantation management of children with SCID and other severe combined immunodeficiencies. Children with other PIDs may require a different set of pre-transplantation requirements. This should be discussed with an immunologist or haematologist. Careful pre-transplantation management is required to optimize the success of HSCT. Avoid live vaccines, including BCG vaccine where possible. If the child has received neonatal BCG vaccination, then rule out disseminated BCG infection. Recent evidence suggests that 51% of children with SCID experiences BCG-related complications, 34% disseminated and 17% localized BCG complications. 14 Also rule out tuberculosis, and active CMV or Ebstein-Barr virus infection [CMV and EBV viral load tests]. Active CMV infection should be managed with intravenous gancyclovir / oral valgancyclovir followed by secondary valgancyclovir prophylaxis. If the patient develops lower respiratory tract infection screen the nasopharyngeal aspirate for respiratory viruses and PCP, and screen the patient for active CMV infection. Where possible treat all active infections aggressively with appropriate antimicrobial agents. Strict infection control practice is absolutely essential o o o o o Ideally the patient should be isolated in a laminar flow facility (positive pressure ventilation). Visitors should be restricted to the parents. If parents have active infections they should avoid patient contact. Implement strict contact precautions and where possible use dedicated nursing and medical personnel on each shift. Ensure that that medical & nursing personnel assigned to the patient do not have active infections. Where possible institute a low germ diet (use sterile feeds) Commence prophylactic medication as soon as possible: o o o TMP-SMX, fluconazole & acyclovir prophylaxis guidelines for SCID are described in table 12 IVIG for children with SCID: use 1g/kg/week TB post-exposure prophylaxis: INH prophylaxis according to standard dosing guidelines (10 mg/kg/day); Note that pre-exposure prophylaxis is not indicated 21 P a g e

22 Nutritional support: Occasionally, patients with severe failure to thrive may require total parenteral nutrition to improve their nutritional status prior to the HSCT Blood products, if required, should always be irradiated to prevent graftversus-host disease, and to minimise CMV transmission blood products should be CMV-negative. The ID and haematology services at RCWMCH are available throughout the pre-transplantation period to support attending doctors Prior to transplantation the haematology service at RCWMCH would ideally counsel the parents regarding the HSCT and the post-transplantation course. Transfer to RCWMCH: Because of constant bed pressures patients from outside Cape Town and who are in the process of being worked-up for HSCT should not be transferred to RCWMCH unless a suitable donor has been identified. Thus the referring clinician must take responsibility for the early stages of pre-transplantation management using the above guidance. Pre-transplantation conditioning (myeloablative chemotherapy) may be indicated when there is residual T-lymphocyte immunity to prevent graft rejection and in unrelated transplants. Conditioning is usually not required for patients undergoing a matched sibling donor HSCT. However, myeloablative chemotherapy may be required prior to an unrelated HSCT. 12, 13, Transplantation and post-transplantation care Transplantation and post-hsct management, including post-hospitalisation follow-up, are co-ordinated through the haematology service, RCWMCH. Prior to the transplantation central venous access is mandatory. Apart from umbilical cord HSCTs, donor stem cells are usually sourced from peripheral blood. Occasionally, stem cells are harvested from the bone marrow compartment by direct aspiration under anaesthetic. After processing the donor stem cells are infused through the central line into the peripheral blood compartment of the recipient. Haematopoietic engraftment usually occurs 14 to 28 days after the stem cell infusion. Consequently T-cell and B-cell immune reconstitution occurs. Posttransplantation graft-versus-host disease (GvHD) prophylactic cyclosporine and/or immunodepletion of stem cells may delay lymphocyte recovery by 3-6 months. Failure of B-cell reconstitution may occur resulting in the need for long-term post-transplantation IRT. Most patients require GvHD prophylaxis (cyclosporine) for at least 3 months post-hsct. During this period ongoing antimicrobial prophylaxis plus IRT (or stabilized human serum infusions) are required. Many centres continue prophylaxis until CD4 counts are greater than 200 cells per µl and PHA proliferative responses of greater than 50% of normal control values are achieved P a g e