Pneumocystis carinii pneumonia. Review of 53 cases.

Between 1976 and 1983, 53 cases of Pneumocystis carinii pneumonia were documented at the Mayo Clinic. Underlying diseases included leukemia in 15 patients, lymphoma in nine, nonhematologic malignancies in five, acquired immune deficiency syndrome in two, an various inflammatory diseases treated by corticosteroids in 16 patients. Cytotoxic drugs with corticosteroids were used in 68 percent of patients, whereas 23 percent received corticosteroids alone. Clinical features consisted of progressive dyspnea (74 percent), cough (55 percent), and fever (62 percent), with normal findings on examination (43 percent), or crackles (53 percent). Arterial oxygen tension and oxygen saturation were 48.6 +/- 12.8 mm Hg and 81.2 +/- 6.5 percent, respectively. Chest roentgenographs exhibited diffuse alveolar and interstitial infiltrates with predominantly perihilar distribution. The diagnostic rates for open lung biopsy and bronchoscopy were 97 percent and 62 percent, respectively. Clinical improvement and survival following appropriate therapy were noted in 22 patients (41.5 percent), whereas the remaining 31 patients died within four weeks of hospitalization. When survivors were compared with nonsurvivors, there was no difference in mean age, leukocyte counts, arterial oxygen tension, or duration of symptoms before treatment. A coexisting pulmonary infection was identified more frequently in nonsurvivors (51.6 percent) than in survivors (22.7 percent, p = 0.01). The mortality from P. carinii pneumonia alone was 47 percent, whereas 76 percent of those with coexisting infection died. Despite antibiotic therapy and potentially effective chemoprophylaxis, P. carinii pneumonia remains a significant and life-threatening complication of diseases or treatments associated with immune suppression.