Antithymocyte globulin adverse effects

Nonspecific immunosuppressive therapy in an adult patient is usually through cyclosporin (35), started intravenously at the time of transplantation, and given orally once feeding is tolerated. Typically, methylprednisone is started also at the time of transplantation, then reduced to a maintenance dose. A athioprine (31) may also be used in conjunction with the prednisone to achieve adequate immunosuppression. Whereas the objective of immunosuppression is to protect the transplant, general or excessive immunosuppression may lead to undesirable compHcations, eg, opportunistic infections and potential malignancies. These adverse effects could be avoided if selective immunosuppression could be achieved. Suspected rejection episodes are treated with intravenous corticosteroids. Steroid-resistant rejection may be treated with monoclonal antibodies (78,79) such as Muromonab-CD3, specific for the T3-receptor on human T-ceUs. Alternatively, antithymocyte globulin (ATG) may be used against both B- and T-ceUs. 

Immunosuppression is used in patients who are not candidates for bone marrow transplantation due to age or to the lack of a donor (up to 70%). Horse antithymocyte globulin (ATG) or rabbit antilymphocyte globulin (ALG) induce haematological responses (transfusion-independence and freedom from infection) in 40-50%. The addition of ciclosporin to ATG or ALG improves response rates to 70-80% and survival rates in responders to 90%. Adverse effects of ATG and ALG include anaphylaxis, exacerbation of cytopenias and serum sickness. Ciclosporin is nephrotoxic. In refractory patients G-CSF and erythropoetin can improve blood counts, as can androgens in some patients. 

The adverse effects of rabbit antithymocyte globulin in transplant recipients were pain and erythema at the injection site and in one instance polyarthritis with urticaria (130). Four cases in which malignant lymphoma developed in renal transplant recipients treated with antithymocyte globulin of animal origin have been reported (131). 

Anti-thymocyte globulin (ATG, thymoglobulin) is a polyclonal rabbit antithymocyte globulin that has been used as an immunosuppressive agent in kidney and hver transplant patients. Despite a fairly high safety profile, reported side effects of ATG include hypertension, leucopenia and ARDS [109]. Renal adverse effects are extremely rare only two case reports describe the occurrence of acute renal failure in patients treated with ATG [110, 111]. Cessation of ATG therapy in both cases and plasmapheresis in one case resulted in full recovery. 

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