[Cell-mediated immunity in patients with Sjogren's syndrome]

Sjögren's syndrome (SS) is considered an autoimmune immunopathological disease, which is characterized by disorders of humoral and cell-mediated immunity. The objective of the work was to assess the ratio of T and B lymphocytes, subpopulations of T lymphocytes and NK cells in the peripheral blood of patients suffering from SS.

The investigated group was formed by 22 patients with the diagnosis of primary SS (mean age 55.7 years, range 39-83 years), 17 patients with the diagnosis of secondary SS (mean age 60.5 years, range 45-79 years). The ration of CD3-, CD4-, CD8-, CD19-, CD5-, CD25- HLA DR- cells in full blood was assessed by the monoclonal antibody technique of direct immunofluorescence, using evaluation by means of a flow cytometer. The results were compared by statistical methods with a control group of blood donors using Student's t-test, A relative increase of the ratio of CD3- T lymphocytes was revealed in patients with primary SS (75.3 +/- 17.9 %, p = 0.380) and secondary SS (73.7 +/- 11.8, p = 0.326), as compared with controls (65.3 +/- 10.3%). The absolute number of the subpopulation of suppressor helper inducer CD4+ T lymphocytes was markedly lower in patients with primary SS (0.056 +/- 0.27 - 10(9)/l, p = 0.0154), as compared with controls (0.81 +/- 0.27, 10(9)/l. The relative number of suppressor cytotoxic CD8- T lymphocytes was significantly higher in patients with primary SS (33.7 +/- 15.0%, p = 0.0001 and secondary SS (30.5 +/- 11.0%, p = 0.0002), as compared with controls (17.2 +/- 6.0%). The absolute number of inhibitory cytotoxic T lymphocytes was significantly higher in patients with primary SS (0.47 +/- 0.3. 10(9)/1, p = 0.0084) and patients with secondary SS (0.48 +/- 0.3, 10(9)/l, p = 0.0072). The relative number of CD57+ NK cells was significantly higher in patients with primary SS (21.1 +/- 11.0%, p = 0.0001) and secondary SS (19.3 +/- 11.7%, p = 0.0023). The absolute number of NK cells was significantly higher in patients with primary SS (0.28 +/- 0.20, 10(9)/l, p = 0.0025 and in patients with secondary SS (0.31 +/- 0.23, 10(9)/l, p = 0.01).

The revealed statistically significant increases in the number of T lymphocytes in patients with Sjögren's syndrome is probably caused by a significant increase of the subpopulation of CD8+ suppressor cytotoxic T lymphocytes. The latter probably overlap with the population of NK cells. These immunological abnormalities are even more marked in patients with primary Sjögren's syndrome due to the decrease of the absolute number of CD4+ helper inducer T lymphocytes.