Pneumocystis carinii pneumonia in renal transplant recipients--clinical and radiographic features, diagnosis and complications of treatment.

Six episodes of Pneumocystis carinii pneumonia in five renal transplant patients on low dose maintenance prednisolone are described. The infection was rare, occurring in 3 per cent of the recipients transplanted between 1978 and 1984. Diagnosis and treatment were not straightforward. Fever was the earliest evidence of illness, and in three episodes the chest radiograph was normal at presentation. At diagnosis, two to 16 days later, all had pulmonary infiltrates and severe hypoxia. Diagnosis was confirmed by cytological examination of bronchial lavage (two), transbronchial biopsy (one), open lung biopsy (one), and for two episodes clinically, from the rapid and complete resolution of fever, pulmonary infiltrates and hypoxia following a therapeutic trial of high dose cotrimoxazole. Pneumocystis antibody titres were low during the illness and in convalescence and did not contribute to diagnosis. Three patients had serological evidence of recent cytomegalovirus infection. All episodes responded to treatment with high dose cotrimoxazole. All the patients survived the illness but one died a year after recovery. The major complications of treatment were thrombocytopenia (three cases) and neutropenia (two cases) which did not respond to folinic acid.