Pneumocystis carinii pneumonia in the transplant recipient

BACKGROUND: The aim of the present was to study the clinical characteristics and prognostic factors of 20 cases of pneumonia by Pneumocystis carinii (NPC) diagnosed over the last 10 years in renal, renopancreatic, liver and bone marrow transplant recipients. METHODS: The clinical histories of all the patients transplanted in the authors' hospital from 1985 to 1994 who developed NPC were analyzed. Diagnosis was established by visualization of cysts in methenamine silver staining of bronchialveolar lavage (BAL) samples. RESULTS: The global incidence of NPC in our transplant population was 1%. However, the incidence was 3% in the recipients who did not receive prophylaxis. No patient in this series received prophylaxis at the time of diagnosis. Ninety percent of the patients had history or rejection. Pneumonia was observed in 15 (75%) in the first 6 months post transplantation. The mean length of the symptoms prior to diagnosis was 10 days. Ninety-five percent of the patients presented cough, dysnea and fever. Radiology demonstrated diffuse alveolointerstitial infiltrates in 18 patients (90%). Basal arterial PO2 was lower than 60 mmHg in 14 (70%) patients and the alveoloarterial gradient of oxygen was greater than 60 mmHg in 9 (45%). Mechanical ventilation was required in 50% of the patients. BAL demonstrated cytologic alterations compatible with CMV infection in 50% of the cases and in two Aspergillus fumigatus was associated. Mortality was 35%. The only variable significantly associated with bad prognosis was the need for mechanical ventilation (p = 0.003). CONCLUSIONS: The incidence of pneumonia by P. carinii in a population of transplant recipients was 1%. No patient received primary prophylaxis at the time of diagnosis. Most of the episodes were observed during the first 6 months post transplant. Mortality was 35% with the only variable with prognostic significance being the need for mechanical ventilation.