Diagnosis of pneumonitis in immunocompromised patients by open lung biopsy.

The records of 59 immunocompromised patients with fever and pulmonary infiltrates who underwent open lung biopsy, were reviewed. A specific diagnosis was made by lung biopsy in 49 (83%) patients, and in 32 instances (54%) the diagnosis was a treatable infection. Only two (3.4%) false-negative biopsies occurred. Transplant recipients were more likely to have a specific, treatable pneumonia (74%) than patients with a reticuloendothelial malignancy (42%, P less than 0.05). This was due to a greater frequency of bacterial pneumonias, primarily due to Legionella, in transplant recipients (P less than 0.01). However, obtaining a specific diagnosis by lung biopsy did not appear to improve outcome. Seventeen of 32 (53%) patients with treatable infections survived, compared to 8 of 16 (50%) with specific, but untreatable, diagnosis and 6 of 11 (55%) with nondiagnostic biopsies. Advanced age and a low platelet count were predictive of death in both transplant recipients and patients with leukemia and lymphoma (P less than 0.05); a high serum creatinine was an additional predictor in renal transplant recipients.