Prognostic value of Ia+ T lymphocytes in bronchoalveolar lavage fluid in pulmonary sarcoidosis

We investigated the value of the Ia+ T-lymphocyte (CD3+ HLA-DR+) ratio in bronchoalveolar lavage fluid (BALF) for predicting the outcome of pulmonary sarcoidosis. Analysis of the BALF Ia(+) T% in 166 patients with pulmonary sarcoidosis by dual-color flow cytometry revealed a wide range of values, of from 0.5 to 85.3%. Although the majority of patients had less than 40% Ia(+) T cells in their BALF, a minor peak was observed at 50 to 60%. The BALF Ia(+) T% value was not influenced by smoking, sex, or age, thus differing from other BALF activation markers. Fifty patients could be followed up precisely for 3 yr after their initial bronchoalveolar lavage (BAL) to evaluate outcome with respect to chest X-ray findings, clinical symptoms, serum angiotensin converting enzyme (ACE) activity, and extrapulmonary involvement. The 50 patients were divided into two groups, with a BALF Ia(+) T% < 40% (n = 34) and greater than or equal to 40% (n = 16), respectively. Serum ACE activity returned to normal within 1 yr in the < 40% group, but remained high for the entire follow-up period in the greater than or equal to 40% group. The significant difference was observed in the persistence of pulmonary involvement between the two groups except for four patients who showed Stage 0 disease (p < 0.02). Thirteen of 31 patients in the < 40% group showed normalization of chest X-ray findings after three years, whereas only one out of 15 patients in the greater than or equal to 40% group showed resolution of pulmonary involvement. Our results suggest that the BALF Ia+ T% may be a novel marker for predicting the long-term prognosis in pulmonary sarcoidosis.