CD5⁺ B Lymphocytes and CD4⁺CD45RA⁺T Cells in Graves' Disease

Abstract

Fifteen patients affected by new-onset Graves' disease with ophthalmopathy have been examined for lymphocyte subset phenotypes by two -colour cytometric analysis. CD5⁺B cells were significantly increased in comparison to the normal population (43.2±20.6% versus 19.5±6.9%; p<0.0009); total T cells showed a normal amount (70.4±9.6%), but the levels of THLADR⁺ cells were significantly increased in comparison to the control group (13.7±10.5% versus 4.7±3.2%; p<0.007). The characterization of the subset suppressor-inducer CD4⁺CD45RA⁺, evaluated as percentage of the total CD4⁺ T cells, showed a significant decrease in comparison with the control group (43.8±13.5% versus 52.3±6.5%; p<0.03). Serum immunoglobulin evaluation showed a statistically significant increase of IgM (p<0.05) and a significant decrease of IgA (p<0.02). A statistical correlation between IgM levels and percentage of CD5⁺ B cells has been found (p<0.04). The defect of suppressor-inducer T cell subset, along with the increase of CD5⁺ B cells may contribute to the pathogenetic mechanism of the disease in patients with a genetically-induced aberrant immune response.