Opportunistic infections in renal allograft recipients.

Two major factors for successful organ transplantation are better control of rejection and better prevention and treatment of infections. In renal allograft recipients, immunosuppressive drug therapy is the major cause of immunocompromised status and occurrence of infections, which arise most commonly as a result of invasion by endogenous opportunists. It may also follow colonization by exogenous environmental organisms and via transfer of cytomegalovirus along with the transplanted kidney. The overall incidence of opportunistic infections varies from center to center; up to 15% of renal transplant recipients die of these infections. Clinical signs and symptoms of infection in immunocompromised patients may be concealed or imitated by the underlying disease, and a high index of clinical suspicion is vital. The unusual pathogens encountered in these patients demand thorough investigation. A total of 84 opportunistic infections encountered in renal allograft recipients during histopathologic and cytopathological evaluation of various specimens during the last 15 years is presented in this report. Invasive fungal infections were the most common pathogens, amounting to 55% of all infections. The dramatic increase in the diversity and number of opportunistic infections detected in these patients is not only due to an increasing population of susceptible individuals but also due to an improved recognition by advanced laboratory diagnostic techniques. The success of management of opportunistic infections depends on strong clinical suspicion, early diagnosis, and prompt treatment. The challenges of early diagnosis of opportunistic infections and prompt treatment are great; the rewards are even greater.