Spontaneous interleukin 2 release of bronchoalveolar lavage cells in sarcoidosis is a codeterminator of prognosis

There is mounting evidence that activated interleukin 2 (IL-2)-releasing lymphocytes play a central role in the immunopathogenesis of sarcoidosis by directing inflammatory reactions and granuloma formation. In the context that a significant proportion of these cells accumulates in the lung and releases mediators, we hypothesized that different immunologically defined stages of sarcoidosis can be identified. A cohort of 89 sarcoidosis patients was allocated to four groups according to the following criteria: stage A, a low number of bronchoalveolar lavage (BAL) lymphocytes (20%) without IL-2 release (1 unit/ml in BAL cell culture supernatant); stage B, BAL lymphocytes20%, with IL-2 release (…