Identification and Characterization of Phospholipase A₂ in the Bronchoalveolar Lavage Fluid of Adult Patients with Adult Respiratory Distress Syndrome

Abstract

Bronchoalveolar lavage fluid (BALF) from patients with adult respiratory distress syndrome (ARDS) were assayed for phospholipase A₂ (PLA₂) activity. Enhanced PLA₂ activity was directly correlated with the severity of the disease. Heparin-Sepharose chromatography showed PLA₂ activity was divided into two distinct peaks.
The heparin-binding fractions appeared to be similar to group II PLA₂ activity. The heparin-non-binding fractions were further purified.
A different type of highly active PLA₂ with high molecular weight and calcium dependency was found. But in a neutral and optimum pH (optinal pH for high molcular mass is 9.0) it did not show immunoprecipitation against antipancreatic PLA₂ antiserum or anti-pig spleen cytosolic 100kDa PLA₂ antiserum. This new type of PLA₂ was detected in the bronchoalveolar lavage fluid of patients with ARDS.