CD5 + B lymphocytes secrete IL-10 rather than TGF-β1 which control the immune response in autoimmune haemolytic anaemia/Evans syndrome.

Objective: To investigate the quantity and secretion function of cytokines-secreted CD5(+) B lymphocytes in Autoimmune Haemolytic Anaemia (AIHA)/Evans syndrome (ES) patients. Methods: Twenty-five untreated AIHA/ES patients, 28 remission AIHA/ES patients and 25 healthy controls (HCs) were enrolled in this study. The quantity of CD5(+)B lymphocytes which produce interleukin-10 (IL-10) (CD5(+)IL-10(+)) and transforming growth factor (TGF-beta 1) (CD5(+)TGF-beta 1(+)) were detected by flow cytometry (FCM). CD5(+) B lymphocytes were sorted from peripheral blood (PB) by FCM and the expression of IL-10 and TGF-beta 1 mRNA in CD5(+) B cells were measured by real-time PCR (RT-PCR). Results: The percentage of CD5(+)IL-10(+)B cells in CD5(+) B lymphocytes in newly diagnosed patients was 82.18 +/- 14.78%, which being significantly higher than that of remission AIHA/ES patients (56.68 +/- 24.39%) and HCs (51.90 +/- 22.95%) (p < .05). The percentage of CD5(+)IL-10(+) B cells in CD5(+) B lymphocytes in newly diagnosed patients was negatively correlated with haemoglobin (Hb), complement 3 (C3) (p < .05) and positively correlated with lactate dehydrogenase (LDH), total bilirubin (TBIL) and indirect unconjugated bilirubin (IBIL) (p < .05). The expression level of IL-10 mRNA in CD5(+) B lymphocytes of newly diagnosed patients (49.34 +/- 22.84) was higher than that of remission patients (3.97 +/- 3.83) and HCs (1.78 +/- 1.66) (p < .05). There was no significant difference among three groups with the proportion of CD5(+)TGF-beta 1(+) B lymphocytes and the expression level of TGF-beta 1 mRNA in CD5(+)B lymphocytes (p > .05). Conclusions: CD5(+) B lymphocytes could secrete IL-10 rather than TGF- beta 1 which control the immune response in AIHA/ES.