Cytotoxic effector function in HLA-associated autoimmune diseases.

Abstract

BACKGROUND: The mechanisms by which cytotoxic-T-lymphocytes (CTLs) and natural killer (NK) cells recognize and kill target cells are the subject of intense research. Previous observations in patients with HLA-associated autoimmune diseases show a major impact of cell-mediated immunity as compared to antibody-mediated immunity. This study analyzes the possible co-operation of NK cells in the autoimmune process, comparing their increase to that of cytotoxic-T-lymphocytes. METHODS: This research examines the incidence of CD8+ T cells and NK cells increases in 1065 patients with various autoimmune diseases. Tissue typing for HLA antigens was carried out in all patients by conventional serologic methods. Lymphocyte subsets (CD4+, CD8+, CD3-HLA-DR+, NK cells, sIg+ B cells) were detected with monoclonal antibodies by a fluorescent cytometer. Results were statistically compared to normal control values by the Student's "t"-test. RESULTS: The analysis of results shows the incidence of CTLs and NK cell increases in patients with different autoimmune syndromes. In some diseases (uveitis, multiple sclerosis, and other neurological autoimmune disorders) raised frequencies of NK cell increase are most evident. These results suggest some possible relationships between CTLs and NK cells in the pathogenesis of the autoimmune process. CONCLUSIONS: The present results show that CTLs and NK cells are implicated in immune dysregulation, which characterizes the complex pathogenesis of autoimmune diseases.