Cellular immunity during follow-up of patients with sarcoidosis of varying duration.

Cellular immunity was followed up at 3 month intervals for 1 year in 43 patients with sarcoidosis representing three well defined categories of the disease viz acute (12), subacute (20) and chronic (11). Twelve apparently healthy individuals served as controls. Each follow-up included the following tests: total number of blood lymphocytes, T cells, B cells, leucocyte migration tests with PPD, BCG and Kveim test material and stimulation tests of lymphocytes in vitro in the presence of PHA, Con A, PPD and PWM. Statistically, the most abnormal initial findings in all the tests were noted in acute sarcoidosis, followed by the subacute group. The acute group showed the most marked changes also during the follow-up. The smallest changes during the follow-up were seen in the patients with the chronic form of the disease. However, the inter-individual variation was considerable and no definite conclusions could be drawn from findings in a given case. Alterations in cellular immunity occur in sarcoidosis. They differ between different subgroups of patients and vary differently in course of time. Well defined criteria for inclusion of patients in an investigation and repeated studies of included patients will increase the information available from investigations of cellular immunity in sarcoidosis.