Surfactant analysis during Pneumocystis carinii pneumonia in HIV-infected patients

Pulmonary surfactant is altered in experimental Pneumocystis carinii pneumonia. Although P carinii is a major causative agent of pneumonia in immunocompromised patients, the pathophysiology of lung injury caused by this organism is poorly understood. Therefore, we studied bronchoalveolar lavage specimens obtained from 19 HIV-infected subjects with PCP compared with specimens from ten healthy control subjects. As iterative BAL was performed, 37 BAL specimens were analyzed for protein and phospholipid. The BAL samples were divided into two groups as follows: 22 BAL samples with the presence of P carinii and 15 BAL samples without P carinii. Compared to control subjects, HIV+ BAL presented a significant increase of PR and a decrease of total PL in both P carinii+ and P carinii- BAL, but in P carinii+ BAL, the fall of PL/PR ratio was significantly more pronounced compared to P carinii- (0.09 +/- 0.02 vs 0.19 +/- 0.04, p less than 0.02). The BAL performed during the recovery of PCP showed an improvement of initial biochemical abnormalities. Surfactant composition was also altered, with a phosphatidylcholine and phosphatidylglycerol drop and a sphingomyelin and lysophosphatidylcholine increase. The presence, even in P carinii- BAL, of less polar compounds of undetermined nature, was revealed. We concluded that in HIV+ patients, abnormalities of pulmonary surfactant were present before PCP, and that the development of PCP enhances these abnormalities. These surfactant alterations may contribute to the saprophyte-pathogen transformation of P carinii, but this hypothesis requires further investigation that is presently in progress.