ELEVATED SURFACTANT PROTEIN-A IN BRONCHOALVEOLAR LAVAGE FLUIDS FROM SARCOIDOSIS AND HYPERSENSITIVITY PNEUMONITIS PATIENTS

Interstitial lung diseases often are accompanied by histopathologic ev idence of alveolar type 2 cell alterations. In the alveolar milieu, th e surfactant-specific protein A (SP-A) is a secretory product of alveo lar type 2 cells. Therefore, we measured SP-A levels in bronchoalveola r lavage (BAL) fluids from patients with untreated sarcoidosis (n=35) and hypersensitivity pneumonitis (HP [n=10]) and compared the results with those from 21 healthy control subjects. In sarcoidosis patients, SP-A was markedly higher than in control subjects with a mean of 8.0 m u g/ml of recovered BAL fluid+/-0.7 SEM (p<0.0001 compared with contro l subjects). In HP, SP-A values were comparable with those in sarcoido sis with a mean of 9.0 mu g/ml +/- 1.7 SEM. Mean SP-A in the control g roup was 4.0 mu g/ml +/- 0.3 SEM. These results suggest that SP-A secr etion is stimulated in sarcoidosis and HP. Further studies seem justif ied to investigate the role of the surfactant system in interstitial l ung diseases as well as the potential clinical usefulness of SP-A meas urements in BAL.