CIRCULATING Y-DELTA-T-CELL-RECEPTOR-POSITIVE LYMPHOCYTES IN SARCOIDOSIS

We investigated phenotypic surface markers of peripheral blood lymphoc ytes including expression of gamma delta T cell receptor (TCR(gamma de lta)) in 185 patients with sarcoidosis and 42 normal subjects. The pro portion of TCR(gamma delta)+ lymphocytes in peripheral blood of patien ts with sarcoidosis (5.5 +/- 5.4%) was significantly higher than in no rmal subjects (3.6 +/- 2.2%; p < 0.05). A number of patients with sarc oidosis had prominently increased levels of circulating TCR(gamma delt a)+ lymphocytes. Successive measurements of circulating TCR(gamma delt a)+ lymphocytes demonstrated the persistence of increased levels of ci rculating TCR(gamma delta)+ lymphocytes. We divided the patients with sarcoidosis into two groups, one with high, the other with low TCR(gam ma delta)+ expression. Compared with the low-value group, the high-val ue group had significantly decreased levels of circulating CD4+ lympho cytes, decreased incidence of a positive tuberculin reaction, and high er levels of serum angiotensin-converting enzyme and lysozyme, suggest ing that these two groups may differ in their immunological response a nd disease activity of sarcoidosis. Measurement of TCR(gamma delta)+ e xpression in the circulation seems to be useful for estimating the dis ease activity of sarcoidosis.