Alveolar T-cell subsets in pulmonary sarcoidosis. Correlation with disease activity and effect of steroid treatment.

Alveolar lymphocytes, obtained by bronchoalveolar lavage in 35 patients with sarcoidosis, were analyzed with monoclonal antibodies to lymphocyte subsets. Untreated patients had significantly higher percentages of Leu 3a (+) T helper-inducer cells (THI) and significantly lower Leu 2a (+) T cytotoxic-suppressor cells (TCS) within the alveolar lymphocyte population than did normal control subjects (p less than 0.002). The mean ratio of alveolar THI to TCS cells was 6.20 +/- 3.76 versus 1.44 +/- 0.54 in control subjects (p less than 0.002). Untreated patients had a percentual enrichment of THI cells among alveolar lymphocytes relative to blood (p less than 0.0002), whereas TCS cells in percent of lymphocytes were lower in alveolar lavage fluid than in blood (p less than 0.002). These shifts were not observed in the control subjects. Patients with high-intensity alveolitis (i.e., T cells constituted 28% or more of alveolar inflammatory cells) had significantly greater proportions of THI cells among alveolar lymphocytes than did those with low-intensity alveolitis (p less than 0.01). This percent of alveolar THI cells correlated positively with the number of lymphocytes and T cells in percent of alveolar cells (p less than 0.03), which both are indexes of disease activity. In untreated patients who were lavaged at least twice, a decrease in the THI/TCS ratio was found to accompany or precede radiologic and clinical improvement, but the initial THI/TCS ratio was not predictive of further evolution. Steroid treatment decreased the THI/TCS ratio with a marked increase in the proportion of TCS cells. These changes were independent of an effect on the number of alveolar lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)