INTRACELLULAR DEFECTS AND PRIMARY IMMUNODEFICIENCIES

Transcription

1 INTRACELLULAR DEFECTS AND PRIMARY IMMUNODEFICIENCIES Rayna Doll, DO, Robert W Hostoffer, DO Allergy/Immunology Fellowship University Hospitals, Cleveland Medical Center, Cleveland, Ohio AGENDA Will discuss mutations of NEMO Will discuss mutations of IPEX Will discuss new primary immunodeficiency involving SEC61A1 NEMO NF-kappa-B essential modulator Aka inhibitor of nuclear factor kappa-b kinase subunit gamma (IKK-γ) 1

2 MUTATIONS: A very rare form of immunodeficiency caused by a mutation of the NEMO (NFkappa-B essential modulator) gene on chromosome Xq28. Hypomorphic mutations in the NFκB essential modulator (NEMO) impair NFκB function and are linked to both immunodeficiency and ectodermal dysplasia (ED) as well as susceptibility to atypical mycobacterial infections. Estimated incidence of NEMO-ID is 1:250,000 live male births. All patients had serious pyogenic bacterial illnesses early in life and the median age of first infection was 8.1mos. Most boys developed mycobacterial disease (median age=84mos) and a minority had herpes viral infections. Initial immunological assessments showed hypogammaglobulinemia (median IgG=170mg/dl) with variable IgM (median=41mg/dl) and IgA (median=143mg/dl). Two patients developed hyper-igm and five developed hyper-iga. All patients evaluated had normal lymphocyte subsets with impaired proliferative responses, specific-antibody production, and NK cell function. 2

3 NEMO NEMO-ID joins a growing list of human genetic defects that impair NK cell function. Infectious susceptibilities common to these disorders suggest an important role for NK cells in host defense. Boys with a NEMO mutation and evidence of impaired specific antibody production should be treated with intravenous immunoglobulin. MAC prophylaxis should be considered because of a high incidence of this infection. Viral disease caused by herpesviruses should be treated aggressively, and a chemoprophylaxis regimen should also be considered. At this time it is premature to comment on stem cell transplantation due to limited experience. Only one patient with Nemo-ID who has undergone successful stem cell transplantation. 3

4 NEMO NEMO-ID is characterized by specific infectious susceptibilities and immunologic impairments and has opened doors to clinical considerations of a new facet of innate immune deficiency, highlighting the importance of innate immunity. These observations also suggest that defects in innate immunity probably are responsible for a portion of the infant mortality rate and that targeted diagnosis of these disorders in families having concerning histories will be beneficial. IMMUNE DYSREGULATION POLYENDOCRINOPATHY ENTEROPATHY X- LINKED Clinical syndrome described by Powell et al (1982). IPEX OUTSIDE (CLINICAL FINDINGS) First described in 1982 by Powell et al. as a syndrome of diarrhea, polyendocrinopathy, and fatal infection in infancy. Neonatal onset diabetes mellitus Hypothyroidism Enteritis (diarrhea/villous atrophy) Hemolytic anemia & thrombocytopenia. Dermatitis: erythema -> eczema psoriasiform Death by 1-2 years of age 4

5 IPEX CLINICAL AND LABATORY FEATURES ENTEROPATHY Watery diarrhea (rarely bloody) Villious atrophy on biopsy Inflammatory bowel disease ENDOCRINOPATHIES Type 1 diabetes Thyroid DERMATITIS Eczema Erithroderma Psoriasiform dermatitis Alopecia LABATORY FINDINDS Elevated IgE OTHER CLINICAL AND LABORATORY FINDINGS HEMATOLOGIC Coombs (+) hemolytic anemia Autoimmune thrombocytopenia Autoimmune neutropenia RENAL Nephrosis or nephritis HEPATIC Autoimmune hepatitis RARE Lymphadenopathy Arthritis and vasculitis AUTOANTIBODIES MAY BE PRESENT AIE-75 (Antibody against gut and kidney specific antigen) ANA Antibody against different organs (thyroid, pancreatic islets, erythrocytes, platelets, smooth muscle) SKIN DISEASE IN IPEX 5

6 IPEX INSIDE (AUTOPSY FINDINGS) PANCREAS: Islets of Langerhans absent with lymphocytic infiltrates INTESTINE: Villous atrophy with lmyphocytic infiltrates LIVER: Cholangitis SPLEEN: Enlarged LYMPH NODES: Follicular hyperplasia THYROID: Lymphocytic infiltrates LUNGS: Consolidation/inflammation THYMUS: Atrophy IPEX VS. IPEX-LIKE PATIENTS CLINICAL 1 IPEX IPEX-Like (n=43) (n=27) Clinical Features No. % No. % Affected Affected Affected Affected Enteropathy Skin Disease Endocrinopathy Diabetes Thyroid Disease Hematologic Disease Nephropathy Hepatitis Neurologic Disease Serious Infections Other Lymphadenopathy Arthritis/Vasculitis IPEX VS. IPEX-LIKE PATIENTS IMMUNOLOGIC FEATURES AND OUTCOMES IPEX IPEX-Like (n=43) (n=27) No. % No. % Immunologic Elevated IgE 19/ /10 60 Elevated IgA 20/ /9 11 Outcomes Alive BMT Dead

7 IPEX Locations of FOXP3 mutations reported ATG>ATA Bacchetta et al 2006 ATG>AGG Myers AK et al 2006 F373A Bacchetta et al 2006 del-6247_-4859 Torgerson TR et al fsX108 Owen CJ et al 2003 T108M & 454+4A>G De Benedetti F et al 2006 IVS9+4G>A Chatila TA et al 2000 From Ochs HD et al. Immunol Rev Feb;203: Review. Clustering of Missense Mutations in FOXP3 PROLINE-RICH DOMAIN ZINC-FINGER LEUCINE ZIPPER FORKHEAD DOMAIN N C XMEN 7

8 XMEN Primary immunodeficiency Group of genetic abnormalities that impairs both humoral and cell-mediated immunity Loss of function mutation of the gene encoding the magnesium transporter MAGT1 2 major consequences: suboptimal T-cell activation and loss of NKG2D on NK and cytotoxic T cells MAGT1 MAGT1 is a cell surface protein that regulates the balance of Mg 2+ between the extracellular fluid and the intracellular free basal pool In T and B cells, MAGT1 participates in intracellular Mg 2+ homeostasis Defect leads to decreased intracellular free Mg 2+ T CELL ACTIVATION Figure 1 - Li F-Y, Chaigne-Delalande B, Su H, Uzel G, Matthews H, Lenardo MJ. XMEN disease: a new primary immunodeficiency affecting Mg 2+ regulation of immunity against Epstein-Barr virus. Blood. 2014;123(14): doi: /blood

9 LOSS OF NKG2D (C) Model of role of MAGT1 in Mg 2+ homeostasis and NKG2D expression Chronic decrease in the basal level of free Mg 2+ leads to loss of expression of NKG2D NKG2D- a receptor on NK and cytotoxic T cells involved in antiviral and antitumor cytotoxicity. Control of EBV-infected cells and tumor surveillance. XMEN is the first PID associated with decreased expression of NKG2D. Figure 1 - Li F-Y, Chaigne-Delalande B, Su H, Uzel G, Matthews H, Lenardo MJ. XMEN disease: a new primary immunodeficiency affecting Mg 2+ regulation of immunity against Epstein-Barr virus. Blood. 2014;123(14): doi: /blood PATIENT PRESENTATION Figure 1 - Li F-Y, Chaigne-Delalande B, Su H, Uzel G, Matthews H, Lenardo MJ. XMEN disease: a new primary immunodeficiency affecting Mg 2+ regulation of immunity against Epstein-Barr virus. Blood. 2014;123(14): doi: /blood REPORTED CASES 7 XMEN patients characterized thus far Because XMEN is an X-linked disease, all patients with clinical disease to date have been males. Most consistent clinical feature among patients is persistent high level of EBV along with increased susceptibility for developing EBV-positive lymphomas Age at diagnosis varies from 3 to 45 years EBV-associated lymphomas have been the only reason some patients with XMEN disease come to medical attention All 4 postpubertal patients have various EBV-associated B-cell lymphoproliferative disorders 9

10 DIAGNOSIS Suspect in cases with: unexplained chronic, especially high level, elevations in EBV viremia (PCR), splenomegaly, and a personal or family history of EBVpositive B cell lymphoproliferative diseases A final diagnosis confirmed by examining MAGT1 mrna expression or MAGT1 exon sequencing Cincinnati Children s Molecular Genetics Laboratory or through the National Institutes of Health Clinical Center TREATMENT Oral supplementation with high dose magnesium L-threonate Restored basal intracellular free Mg 2+ along with NKG2D expression and decreased the number of EBV-infected cells in two XMEN patients Rituximab (anti-cd20 antibody) will likely reduce the level of EBVinfected cells in the blood Two patients with XMEN and lymphoma underwent allogeneic HSCT but did not survive because of transplant-related complications HSCT might still be curative for patients with a good match These patients have a high incidence of primary and secondary lymphomas PLASMA CELL DEFICIENCY IN HUMANS WITH HETEROZYGOUS MUTATIONS IN SEC61A1 Desirée Schubert 1, 2, Marie-Christine Klein 3, Sarah Hassdenteufel 3, *Andrés Caballero- Oteyza 1, Linlin Yang 1,2, Michele Proietti 1, Janine Kemming 1, Johannes Kühn 1, Sandra Winzer 1, Stephan Rusch 1, Manfred Fliegauf 1, Alejandro A. Schäffer 4, Stefan Pfeffer 5, Adolfo Cavalié 6, Hongzhi Cao 7, Fang Yang 7, Yong Li 8, Anna Köttgen 8, Marta Rizzi 9, Hermann Eibel 1,Robin Kobbe 10, Amy Marks 11, Brian P. Peppers 11 Robert W. Hostoffer 11, Jennifer M. Puck 12, Richard Zimmermann 3 and Bodo Grimbacher 1,13 10

11 HUMORAL DISORDERS Most common primary immunodeficiency Typically a defect of antibody production Defects most typically found in maturation and signaling We describe the first defect involving plasma cells directly PLASMA CELLS Terminal differentiation of B cells Secret Immunoglobulin Require endoplasmic reticulum for unfolding and processing of immunoglobulin prior to secretion. In the ER of plasma cells, pores are used to transfer these immunoglobulin, other proteins and calcium in and out. One of these pore types is called SEC61 aka translocon SEC61 has both an alpha and gamma subunit Each of these subnits have isoforms labeled 1 and etc. SEC61A1 is located on chromosome 3 11

12 Hypogam/CVID + Hypogam/CVID - Patient 1 Patient 0 Patient 2 Patient 3 Patient 4 Patient 5 Patient 6 Patient 7 Patient 8 Patient 9 Patient 10 Patient 11 Patient 12 9/18/2017 Figure 1: Family Tree??? Figure 2: Individual Illnesses and Ages Infant: 0-2 years, Childhood: 3-12 years, Adolescent: years, Adulthood: 18+ years, RSV: Respiratory Syncytial Virus, URI: Upper Respiratory Infection, TM: Tympanic membrane Table 1: Presenting Immunoglobulin Levels, Pneumococcal Response and Tetanus antitoxoid IgG Patient # IgG mg/dl IgA mg/dl IgM mg/dl Pneumococcal Tetanus antitoxoid response IgG Ab L* 39 L* 33 L* No response 1.34 Protective 3** L* No response 1.16 Protective 4 693L* 58 L* 14 L* No response N/A L* 27 L* 26 L* No response 0.29 Intermediate L* 22 L* 22 L* No response N/A L* 37 L* 27 L* No response N/A L* 31 L* 12 L* No response 0.16 Intermediate L* 8 L* 13 L* No response 0.34 Intermediate L* <7 L* <10 L* No response*** <0.10 Undetectable L* Lab values are reported low per individual laboratory standard ranges. **Patient 3 original levels in 2000 were all low: 430/23/9 (IgG/A/M mg/dl) *** Patient 10 was not tested in 2004, later tested in

13 Table 2: Individual Immunodeficiency Profiles Patient CD3% CD3abs L* CD3 + CD4% 27 L* CD3 + CD4abs L* CD3 + CD8% 39 H* CD3 + CD8abs CD4:CD L* CD19% CD19abs CD16/ CD16/56 abs L* or Lab values are reported either low or high per individual laboratory standard ranges. SEC61 MUTATIONS ASSOCIATED WITH DISEASE 13

14 SEC61A1 MUTATION Humoral deficiencies are the most common primary immunodeficiencies Humoral defects are those primarily involved with maturation and signaling SEC61A1 mutation is the first defects that involves plasma cell function and sustainability. 14

15 CONCLUSIONS Primary Immunodeficiencies were initially thought to be rare In reality all of us are associated with a small defect in our immune system It is just a matter of the right organism at the right time that will make the deficiency obvious. 15