Prognostic indicators in the initial presentation of Pneumocystis carinii pneumonia.

We prospectively evaluated 150 consecutive patients with Pneumocystis carinii pneumonia (PCP) as their sole initial manifestation of AIDS (group 1). Admission laboratory and radiographic criteria were analyzed for diagnostic and prognostic indicators and compared with those of patients presenting with non-PCP pulmonary manifestations of AIDS (group 2). Mean admission serum LDH level was 465 +/- 67 IU/L in PCP patients (group 1) and 211 +/- 28 IU/L in group 2 (p less than 0.01). Seventy-eight percent of PCP patients (117 of 150) survived. Comparing survivors with nonsurvivors, the mean admission LDH level was 394 +/- 45 vs 717 +/- 51 IU/L (p less than 0.01), and the mean P(A-a)O2 gradient was 42 +/- 6 vs 55 +/- 6 mm Hg (p less than 0.05). Serum LDH levels and P(A-a)O2 gradients have diagnostic and prognostic implications in patients with AIDS-related PCP.