Abstract
Objective:
Autoimmune hemolytic anemia (AIHA)/Evans syndrome is a form of immune-related cytopenia characterized by autoantibodies directed against red blood cells. A subset of B lymphocytes expressing CD5 is found in patients with AIHA/Evans syndrome. Previous studies have shown that the number of CD5+ B lymphocytes is correlated with the severity of AIHA/Evans syndrome. IL-10 can be induced in various types of human B cells, including naive, memory, and CD5+B cells, following B-cell activation by Th-cell-dependent and TLR-dependent signals. This study is to investigate the secretion function of CD5+ B lymphocytes in AIHA/Evans syndrome (ES) patients.
Methods:
25 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+) were detected by flow cytometry. CD5+ B lymphocytes were sorted from Peripheral blood (PB) by CytoFLEX Flow Cytometer. The expression of IL-10 mRNA in CD5+ B cells were measured by real-time PCR (RT-PCR). The concentrations of IL-10 in serum were detected by Enzyme-linked Immunosorbent assay (ELISA).
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 HC (51.90±22.95%)(p<0.05). The percentage of CD5+IL-10+ B cells in CD5+ B lymphocytes in newly diagnosed patients was negatively correlated with their serum level of hemoglobin, C3 (P<0.05) and positively correlated with their serum level of LDH, TBIL and IBIL (P<0.05).
The expression level of CD5+ B lymphocytes IL-10 mRNA in newly diagnosed patients (49.34±22.84) was higher than that of remission patients (3.97±3.83) and HC (1.78±1.66) (P<0.05).
The concentration of IL-10 in serum in newly diagnosed patients (4.01±1.54 pg/ml) was lower than that of remission patients (5.08±1.72pg/ml) and HC (5.70±1.60pg/ml) (P<0.05).
Conclusions:
Most CD5+ B lymphocytes secrete IL-10 in AIHA/Evans patients and are positively correlated with the severity of the disease. The increased quantity of CD5+IL-10+ B cells and the decreased cytokines-secreted level maybe involved in the occurrence of AIHA/Evans syndrome.
No relevant conflicts of interest to declare.
