Borderline rejection after renal transplantation--to treat or not to treat.

According to the Banff classification of renal allograft pathology, the category borderline changes defines changes insufficient for a diagnosis of acute rejection. The relationship between borderline changes and acute renal allograft rejection still remains unclear. The appropriate clinical management for patients showing such changes is controversial. One possible interpretation of the high incidence of subacute tubulitis is that these changes in the absence of graft dysfunction are of no consequence and that treatment with intensified immunosuppression is unnecessary and perhaps harmful. Another view, consistent with the high incidence of CAN in late protocol biopsy studies, is that immunosuppression has become so powerful, that rejection may not even be manifested by a rising serum creatinine. Borderline changes should be used as part of an algorithm, but not as the only criterion, for therapeutic decision making. Based on the weak evidence of existing studies, in our patients with clinical borderline rejection, we have to weigh the individual immunological risk against the potential side effects of increased immunosuppression. Even in the knowledge that a majority of patients with borderline infiltrates will not progress into rejection, in many transplant centers, borderline rejection is treated with additional steroids or augmentation of maintenance immunosuppression.