Pulmonary sarcoidosis: alterations in bronchoalveolar lymphocytes and T cell subsets

Peripheral blood and bronchoalveolar lavage lymphocyte subpopulations have been evaluated in 14 patients with pulmonary sarcoidosis and eight normal subjects, monoclonal antibodies of the leu series being used. No significant alterations of T lymphocyte subpopulations were found in the peripheral blood of sarcoidosis patients. There was, however, a significantly greater proportion of T suppressor-cytotoxic cells (36.0 (SD 17.6%] in the bronchoalveolar lavage fluid of patients than of normal subjects (15% (5.6%); p less than 0.01), but a decrease in the proportion of T helper-inducer cells (51.1% (18%) v 79.3% (9%). These changes correlated with the duration of the disease but not with other clinical, radiological, physiological, or biochemical criteria. Patients were followed up for six to 20 months and five patients had a repeat bronchoalveolar lavage and lymphocyte subpopulation evaluation after three to 14 months. The initial pulmonary T lymphocyte subset proportions were not predictive of clinical, physiological, or radiological alterations during follow up. There was also no consistent pattern in the relationship between change in T subset proportions and change in clinical physiological, and radiological features in the five patients having a repeat lavage. Lymphocyte surface marker studies may indicate immunopathogenetic mechanisms in sarcoidosis but do not appear to be good predictors of clinical outcome.