CD5 B Cells in autoimmune and non immune-mediated thyroid dysfunctions.

In a previous study we demonstrated a significant increase of CD5+ B subset in patients with Graves' disease (GD) compared with normal controls. The aim of this study was to compare the percentage of CD5+ B and CD5- B cells in GD with that in different forms of autoimmune and non immune-mediated thyroid diseases.Seventy-two patients were studied: 28 patients with GD, 20 with silent thyroidltis (ST), 12 with Hashimoto's disease (HD), and 12 subjects affected by hyperthyroidism due to toxic adenoma (TA). Eleven out of 28 patients with GD were also evaluated after six months of methimazole treatment. The study was performed by cytometric analysis.In GD the percentage and the absolute number of CD5+ B cells were significantly increased compared with normal controls (42.5±18.2% versus 19±6.3%, p<0.0001; 142.1±153.3/cmm versus 46.9±22/cmm, p<0.003, respectively). CD5+ B cells tended to normalise after six months of treatment. In ST the percentage of CD5+ B cells was increased (28.6±10.2%); conversely the absolu...