Objective: To determine the clinical spectrum of immunosuppressive conditions and systemic corticosteroid therapy associated with the development of Pneumocystis carinii pneumonia in a consecutive series of patients without acquired immunodeficiency syndrome (AIDS).
Design: We retrospectively analyzed a consecutive series of 116 patients without AIDS who were assessed at Mayo Medical Center for a first episode of P. carinii pneumonia between 1985 and 1991.
Methods: Medical records were examined to determine underlying immunosuppressive disorders, premorbid corticosteroid dosage and duration of therapy, associated infections, and subsequent respiratory failure and in-hospital mortality.
Results: Conditions associated with a first episode of P. carinii pneumonia were hematologic malignant disorders (30.2%), organ transplantation (25.0%), inflammatory disorders (22.4%), solid tumors (12.9%), and miscellaneous conditions (9.5%). Regardless of the associated underlying disease, corticosteroids had been administered systemically in 105 patients (90.5%) within 1 month before the diagnosis of P. carinii pneumonia. The median daily corticosteroid dose was equivalent to 30 mg of prednisone; however, 25% of patients had received as little as 16 mg of prednisone daily. The median duration of corticosteroid therapy was 12 weeks before the development of pneumonia; however, P. carinii pneumonia developed after 8 weeks or less of corticosteroid therapy in 25% of these patients. Respiratory failure occurred in 43%, and in-hospital mortality was 34% for patients with P. carinii pneumonia in conditions other than AIDS.
Conclusion: Although these results do not suggest that premorbid administration of corticosteroids is the only factor that contributes to the development of P. carinii pneumonia in these patients, they show that, in this large consecutive series, systemic corticosteroid therapy, even in moderate doses, was administered to most patients during the month preceding the onset of P. carinii pneumonia. Consideration should be given to instituting P. carinii prophylaxis (when not contra-indicated) in patients for whom prolonged systemic corticosteroid therapy is prescribed.