Opposite changes of regulatory T cell blood content may differentially contribute to atherosclerosis or lymphoproliferative disorders

Background. Chronic autoimmune inflammation in arterial wall may lead to atherosclerosis progression. Objective. The aim of this study was to investigate the association between Treg, Th17 and B1a cell blood frequencies as well as IgM autoantibodies to oxLDL and the abundance of carotid atherosclerosis. Material and methods. 18 patients with increased IMT (intima-media thickness) and 65 patients with different severity of carotid atherosclerotic plaques were included. Treg, Th17 and B1a cell blood frequencies were assessed via direct immunofluorescence staining and flow cytometry, oxLDL as well as IgM autoantibodies to oxLDL were measured with commercial kits. Results. We observed higher values of Treg in patients without carotid atherosclerosis. Patients with intact carotid arteries as compared to patients with mild atherosclerotic plaques had decreased Th1 levels. OxLDL IgM levels were higher in patients with intact carotid arteries. Patients who received statin treatment had higher levels of Treg. Immunophenotyping of B cells revealed two cases of monoclonal B-cell lymphocytosis and 1 case of B-CLL (B-cell chronic lymphocytic leukemia) in elderly patients with intact carotid arteries. Conclusion. We hypothesize that certain parameters of cell immunity may hamper atherosclerosis while protecting from lymphoproliferative disorders.