Persistent bronchoalveolar lymphocytosis in asymptomatic farmers

We previously demonstrated that 14 of 23 asymptomatic dairy farmers with positive precipitins and 5 of 20 without precipitins had an alveolar lymphocytosis (greater than 22%). To verify the outcome of this lymphocytosis, we restudied, 2 or 3 yr later, 27 of these subjects. No subject had had symptoms suggestive of farmer's lung disease either prior to the initial study or between the 2 studies. All were still on their farm. Physical examination and chest roentgenograms were normal for all subjects at both studies. Pulmonary function tests showed a small but significant change in RV (101.8 +/- 20.4% to 118.7 +/- 27.6% of predicted, p less than 0.05) and FVC (98.0 +/- 12.6% to 94.3 +/-9.5%, p less than 0.05), whereas TLC, FEV1, and DLCO showed no changes. Lymphocytes from BAL were still increased in 9 of 12 subjects, whereas 3 had returned to normal; of the 15 subjects with previous normal values, 3 now had an abnormal lavage lymphocytosis. There was no correlation between lung function variations and the percentage of lymphocytes in the previous or the present BAL. We conclude that a bronchoalveolar lymphocytosis is a persistent phenomenon in a large number of asymptomatic dairy farmers, and that this finding is not related to significant disease, at least in the time span studied.