Pneumocystis carinii pneumonia in HIV-negative immunocompromised adults

To identify patient populations at risk of Pneumocystis carinii pneumonia (PCP) and assess the potential role of chemoprophylaxis.

Review of cases of PCP among patients admitted to a tertiary referral hospital in Sydney between January 1990 and April 1993. Cases were identified by indirect immunofluorescent antibody microscopy performed on respiratory tract specimens.

Ninety-two episodes of PCP were diagnosed in 64 HIV-positive patients and 28 others. All HIV-negative patients had received corticosteroids combined with other immunosuppressive agents before the onset of PCP symptoms, which occurred within six months of immunosuppression. The group included nine of 150 kidney transplant recipients (6%) six of 138 liver transplant recipients (4.3%) and three of 25 patients with Wegener's granulomatosis (12%). Mortality associated with PCP in HIV-negative patients was significantly higher than in those who were HIV-positive (32% v. 8%, P < 0.005).

Solid organ transplant recipients and individuals receiving treatment for Wegener's granulomatosis have a significant risk of developing PCP. Given the high mortality associated with this disease in HIV-negative patients, primary PCP chemoprophylaxis should be considered during the first six months of immunosuppression.