Analysis of induced sputum for the diagnosis of recurrent Pneumocystis carinii pneumonia.

We studied the sensitivity of ISA for diagnosis of second-episode PCP in AIDS patients. We induced sputum in 218 patients who had known or suspected AIDS and who had a presentation suggestive of PCP. All patients with negative sputum smear for PCP underwent BAL. Twenty-five patients were identified who had second-episode PCP at least 30 days after initial diagnosis. Chest roentgenographic infiltrate patterns for these 25 patients were blindly scored as normal, diffuse, upper lobe or focal non-upper lobe. The sensitivity of ISA was 72 percent for the first episode of PCP, 72 percent for the second episode of PCP, 72 percent for patients with second-episode PCP who had initial PCP detected by ISA and 71 percent for patients with second-episode PCP whose first episode of PCP was missed by ISA. Of the ten patients who were treated with AP, only one had a false-negative sputum analysis. A comparison of patients who had second-episode PCP diagnosed by ISA with those who had false-negative sputum analysis showed no difference in time to relapse, chest x-ray film pattern (all diffuse) or use of AP.