What is chronic rejection?

Chronic rejection (CR) involves progressive deterioration of the transplanted organ’s function. The targets of the immune response are different from the targets in acute rejection. This damage occurs very slowly and is not a result of recurrent episodes of acute rejection. The main cause of CR, as with acute rejection, is too little immunosuppressive medication—either because the patient does not take his or her medications as prescribed or because the transplant physician reduces the dose in an attempt to avoid side effects. CR may be exacerbated by factors such as CMV infection, high cholesterol levels, diabetes, or hypertension.

Thanks to earlier recognition of acute and chronic rejection and the introduction of more powerful immunosuppressive agents (for example, tacrolimus and sirolimus), many of these cases can be successfully reversed.