Anaphylaxis Angioedema Transplantation & graft rejection 1
Learning objectives 1.Anaphylaxis: definition, causes, C/P, Ix, Rx 2.Angioedema: definition, causes, C/P, IX,RX 3.Transplantation & graft rejection: definition, determinants, complications, classification. 4. Complications of immune suppression& Immunosuppressive drugs used in transplantation 5. HLA linked disorders 6. Immunizations: benefit, and types 7. Summary 8.Quiz 2
ANAPHYLAXIS Definition Acute medical emergency. Systemic allergic reaction. Due to release of histamine and other vasoactive mediators. Causes 1.Anaphylaxis: IgE mediated mast cell degranulation 2.Anaphylactoid: Non-IgE 3
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C/P of anaphylaxis Acute severe systemic allergic reaction PF: foods, latex, insect venom and drugs A history of previous local allergic responses to the offending agent 6
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Investigations 1)Serum mast cell tryptase 2)Specific IgE tests Management 5-immediate management includes: ABCDT 1)A:Airways: ensuring airway patency 2)B:Breathing: administration of oxygen 8
Patent airways 9
Oxygen adminstration 10
3) C:Circulation: restoration of blood pressure (laying the patient flat, i.v fluids) 4) D: Diagnosis: anaphylaxis & risk factors 11
i.v fluids 12
5)T: Treatment:: Adrenaline (epinephrine) i.m (adult dose, 0.3-1.0 ml 1:1000 solution) and repeated at 5-10 minute intervals if the initial response is inadequate. intravenous antihistamines :chlorpheneramine10-20 mg i.m. or slow i.v. injection Corticosteroids: hydrocortisone 100-300 mg i.v Supportive treatments including nebulised β 2 - agonists Identify the trigger factor: removal + avoidance 13
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Education: Patients who previously experienced an anaphylactic event should be prescribed self-injectable adrenaline and they and their families or carers should be instructed on its use. Use of a Medic Alert bracelet (or similar) will increase the likelihood that adrenaline will be administered in an emergency. Referral to specialist assessment 15
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ANGIOEDEMA Definition Is the episodic, localized, non-pitting swelling of submucous or subcutaneous tissues alone ±urticaria mechanism is degranulation of mast cells or increased local bradykinin concentration 17
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Transplantation & Graft Rejection Transplantation: is the definite Rx of end organ disease. Graft rejection: is an aggressive immune response by the recipient. Determined by : the genetic disparity between the donor and recipient, the immune status of the host and the nature of the tissue transplanted The most important genetic determinant is the difference between donor and recipient HLA proteins 20
Value of compatible HLA loci acute rejection. graft survival. intense immunosuppressive protocols. 21
Number of solid organ transplants 22
Organ transplantation complications Rejection Genetic disparity. CD8 & macrophage mediate most of the rejection -swelling & pain over the allograft GVHR -Allografted immune competent tissue( e. g b.m) recognises recipient as foreign tissue. CMI damage to the recipient - Skin rash, diarrhea,& jaundice 23
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Acute cellular rejection is the most common form of graft rejection. Chronic allograft failure (chronic rejection) is a major cause of graft loss. Investigations to avoid rejection HLA typing Anti-HLA antibody screening Donor-recipient cross-matching C4d staining: useful in the early diagnosis of vascular rejection 25
Complications Of Transplant Immunosuppression 1)Infection : opportunistic infections:- CMV -Pneumocystis 2) Malignancy: because T-cell suppression ----------------- failure to control viral infections -Epstein-Barr virus-- lymphoma -human herpesvirus 8---- Kaposi's sarcoma -human papillomavirus----- skin tumours 26
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Immunization 29
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Summary Anaphylaxis: AME should be Dx & Rx early. Angioedema is episodic, localized, non-pitting swelling of submucous or subcutaneous tissues. 4 imp types. Transplantation: is the definite Rx of end organ disease. Graft rejection: is an aggressive immune response by the recipient. Organ transplantation complications: rejection & GVHR 31
Summary Types of reject: hyperacute, acute, & chronic Imuunosupp dr: x -proliferat, calcineurin x,corticosteroids, x T-cell induction Certain disorders associated w specific HLA type. Immunization: natural & artificial : active & passive means. 32