Phospholipids and microviscosity study in broncho-alveolar lavage fluids from control subjects and from patients with extrinsic allergic alveolitis.

Bronchoalveolar lavages were studied in control subjects and patients with extrinsic allergic alveolitis. Phospholipids, fatty acid composition of the different phospholipid species found and cholesterol were investigated. In allergic alveolitis, the phosphatidylcholine was absent, whereas two usually minor components in lung surfactant, phosphatidylethanolamine and phosphatidylinositol, were considerably enhanced. The tensio-active properties of the phospholipids present in fluids were investigated by a fluorescence polarization technique. Microviscosity of the phospholipids was studied, using 1,6-diphenyl-1,3,5-hexatriene. High values for the microviscosity were encountered in samples from patients. Phosphatidylethanolamine present at a high level exhibits the highest microviscosity. Saturated fatty acids in phospholipids and cholesterol are rigidifying factors contributing to the high microviscosity values found in allergic alveolitis. Moreover, one very important point microviscosity values found in allergic alveolitis. Moreover, one very important point brought out by the this technique is its full independence from the fluid volume recovery.