Markers of activity in clinically recovered human leukocyte antigen-DR17-positive sarcoidosis patients.

Scandinavian human leukocyte antigen-DR17-positive (DR17+) sarcoidosis patients are characterised by a good prognosis. They also reveal an accumulation in bronchoalveolar lavage fluid of T-lymphocytes expressing the T-cell receptor V gene segment AV2S3 at disease onset. The authors of this study wished to establish whether AV2S3 T-lymphocyte accumulation changes from disease onset to clinically resolved disease and how this relates to other activity parameters. Bronchoalveolar lavage fluid and serum from nine DR17+ sarcoidosis patients were examined at disease onset and after spontaneous resolution of clinical and radiographical signs of disease. Nine DR17+ patients with lung accumulated CD4+ AV2S3+ T-cells were investigated after clinically recovery. At re-examination the percentage of CD4+ AV2S3+ lymphocytes in bronchoalveolar lavage fluid was normalised (29 versus 5.4%). A significant reduction in lymphocyte percentage (14 versus 4.4%) and a decrease in cellular concentration (179x10(6) x L(-1) versus 111x10(6) x L(-1)) and CD4/CD8 ratio (5.2 versus 2.4) were also seen. In serum, the activity of angiotensin-converting enzyme (24.9 versus 14.0 U x mL(-1)) as well as the levels of neopterin (7.8 versus 5.3 nmol x L(-1)) decreased significantly after recovery. These results indicate that the locally accumulated AV2S3 positive T-lymphocytes in bronchoalveolar lavage are involved in the pathogenic process of sarcoidosis in this patient group.