Circulating TCR gamma delta cells in the patients with systemic lupus erythematosus

SYSTEMIC lupus erythematosus (SLE) is a disorder with a wide range of immun ological abnormalities. The results of the studies undertaken ill the last decade indicated that SLE pathogenesis was mainly connected with the breakd own of the activation control of B and T cells, generating humoral or cell- mediated responses against several self-antigens of affected cells. The las t studies demonstrate that the role of gamma delta T lymphocytes in autoimm une diseases can be especially important. Flow cytometry techniques were us ed to investigate the number and percentage of TCR gamma delta T cells and their most frequent subtypes in peripheral. blood of 32 patients with SLE a nd 16 healthy volunteers. We also correlated TCR ya cells number with the l evel of T CD3(+), T CD4(+), T CD8(+), and NK (CD16) cells (cytometric measu rements) and SLE activity (on the basis of clinical investigations). Our st udies were preliminary attempts to evaluate the role of that minor T cell s ubpopulation in SLE. Absolute numbers of cells expressing gamma delta TCR i n most SLE blood specimens were significantly lower than in the control gro up (P<0.006). However, since the level of total T cell population was also decreased in the case of SLE, the mean values of the percentage gamma delta T cells of pan T lymphocytes were almost the same in both analysed populat ions (7.1% vs 6.3%, respectively). In contrast to V delta 2(+) and V gamma 9(+) subtypes of pan gamma delta T cells, V delta 3(+) T cells number was h igher in SLE patients (20 x 10 cells/mu l) than in healthy control group (2 x 2 cells/mu l) (P=0.001). However, we found no differences between the nu mbers of pan gamma delta T lymphocytes and studied their subtypes in the pa tients with active and inactive disease. These cell subpopulations were dou bled In the treated patients with immunosuppressive agents In comparison wi th untreated ones; however, data were not statistically significant. Our st udy indicated that V delta 3(+) subtype of gamma delta T cells seems to be involved in SLE pathogenesis; however, we accept the idea that the autoimmu nity does not develop from a single abnormality, but rather from a number o f different events.