Bronchoalveolar lavage cell and lymphocyte phenotype profiles in healthy asbestos-exposed shipyard workers

The cellular and lymphocyte phenotypic composition of bronchoalveolar lavage (BAL) fluid and peripheral blood (PB) from 15 healthy, nonsmoking, asbestos-exposed shipyard workers (AEW) and 10 nonsmoking, age-matched unexposed workers (UEW) were compared. None of the AEW had clinical, radiographic, or physiologic evidence of asbestosis, but six had radiographic evidence of pleural plaques and/or thickening. The mean duration of asbestos exposure was 16.3 +/- 2.3 yr, and the mean period since exposure was 10.8 +/- 0.5 yr. All but three of the AEW and none of the UEW had asbestos bodies detected in the first 20 ml of BAL fluid recovered (0.1 to 35 asbestos bodies/ml). The AEW had a significantly higher mean percentage (19.1 +/- 2.8% versus 9.7 +/- 1.6%) and concentration (31.6 +/- 5.2 x 10(3) cells/ml versus 14.7 +/- 2.5 x 10(3) cells/ml) of BAL lymphocytes compared with that in the UEW, with an increased mean concentration of each phenotype measured. In PB, the mean lymphocyte concentration was also higher in the AEW than in the UEW (2.0 +/- 0.3 x 10(3) cells/ml versus 1.5 +/- 0.3 x 10(3) cells/ml), but the difference was not statistically significant, and there was no increase of any phenotype measured. BAL lymphocytosis did not correlate with exposure history or BAL asbestos body count, but was greater in AEW with pleural abnormality (30.1 +/- 2.9% versus 11.8 +/- 1.6%). BAL concentrations of CD-20, CD-3, and CD-4, but not of CD-8 cells were significantly increased compared with those in the AEW without pleural abnormality. Further longitudinal studies are needed to determine the prognostic significance of these findings.