Immunological studies in sarcoidosis: a comparison of disease activity and various immunological parameters.

We found it valuable to separate the heterogeneous types of sarcoidosis into more homogeneous groups on the basis of activity and duration of the disease. This view is supported in the present study by the finding of a marked depression of T-cell function in patients with chronic-active sarcoidosis. Patients with acute or chronic-inactive disease had only moderately depressed T-cell function as measured by tuberculin skin test and DNCB index. These results are in agreement with those of some previous investigations. The remainder of the abnormal findings, particularly low total number of circulation T lymphocytes, elevated serum IgG levels, and presence of autoantibodies, could not be correlated to disease activity, extent of the disease, or T-cell function. We have found no explanation for the presence of autoantibodies but suspect that they may be nonspecifically related to the disease process.