You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All are given to prevent rejection in organ transplantation except: and explain in detail?
Ans: a (Hyperimmune sera) Ref: Davidson, 20th ed, p. 90IMMUNOSUPPRESSIVE DRUGS USED IN TRANSPLANTATIONDrugAnti-proliferativeagentse.g. Azathioprine,Mycophenolate mofetilMechanism of actionInhibit DNA synthesis: block lymphocyte proliferation and cytokine synthesisMay be directly cytotoxic at high dosesMajor adverse effectsIncreased susceptibility to infectionLeucopeniaHepatotoxicityCalcineurin inhibitors e.g. cyclosporin, tacrolimusInhibit T-cell signaling: prevents lymphocyte activation and blocks cytokine transcriptionIncreased susceptibility to infectionHypertensionNephrotoxicityDiabetogenic(especially tacrolimus)Gingival hypertrophy, hirsutism (cyclosporin)CorticosteroidsDecrease phagocytosis and release of proteolytic enzymes; decrease lymphocyte activation and proliferation; decrease cytokine production; decrease antibody productionIncreased susceptibilityto infectionOther complicationsAnti-T-cell induction agents anti-thymocyte globulin (ATG), anti-CD3 monoclonal antibodyDepletion or blockade of T cells by antibodies to cell surface proteinsProfound non-specific immunosuppressionIncreased susceptibility to infectionInvestigations to avoid rejectionHLA typingHLA typing using genetic or serological assays determines an individual's HLA polymorphisms, and facilitates donor-recipient matching.Anti-HLA antibody screeningPotential transplant recipients are screened for the presence of anti-HLA antibodies using either recombinant HLA proteins or a pool of lymphocytes from individuals with broadly representative HLA types. If antibodies are detected, their specificity is further characterised and the recipient is excluded from receiving a transplant which carries these alleles.Donor-recipient cross-matchingCross-matching is a functional assay that directly tests whether serum from a recipient (which potentially contains anti-donor antibodies) is able to bind and/or kill donor lymphocytes. It is specific to a prospective donor, and is done immediately prior to transplantation. A positive cross-match is a contraindication to transplantation because of the risk of hyperacute rejection.C4d stainingC4d is a fragment of the complement protein C4, and deposition of C4d in graft capillaries indicates local activation of the classical complement pathway. This is specific to antibody-mediated damage and is useful in the early diagnosis of vascular rejection.