The Expression of BTK/p-BTK Is Different between CD5+ and CD5- B Lymphocyte from Autoimmune Hemolytic Anemia/Evans Syndromes

Abstract Objective To investigate the expression level of Bruton's tyrosine kinase (Btk) on CD19+B lymphocytes in peripheral blood (PB) of autoimmune hemolytic anemia (AIHA)/Evans patients. Methods The expression of Btk and Phosphorylated Btk(p-Btk) on CD5+CD19+B and CD5-CD19+B lymphocytes were detected using flow cytometry in AIHA/ Evans patients with different disease states, healthy controls (HC) and chronic lymphocytic leukemia (CLL) patients and analyzed its correlation with clinical parameters. Results 36 AIHA/ES patients (16 hemolytic, 20 remission), 11 CLL patients and 15 healthy controls (HC) were enrolled in this study. The expression of Btk and p-Btk on CD5+B lymphocytes in AIHA/Evans patients were higher than those in HCs and CLL patients, the latter two groups had no significant difference, and were positively correlated with the quantity of IgE. The ratio of p-Btk to Btk on CD5+B lymphocytes of hemolytic group and remission group was obviously higher than that on CD5-B lymphocytes [(74.62±6.42)%, (29.63±10.19)%, P=0.001], [(77.95±9.57)%, (26.29±6.86)%, P=0.006]. The ratio of p-BTK to BTK on CD5+B lymphocytes [(54.89±9.56)%] and CD5-B lymphocytes [(30.86±12.47)%, P=0.109)] showed no significant difference in HCs. There was no significant difference of Btk on CD5+B and CD5- B lymphocytes in AIHA/Evans patients, but the expression of p-Btk on CD5+B lymphocytes significantly higher than that on CD5-B lymphocytes in AIHA/Evans patients. Conclusion The expression levels of p-BTK in different B cell subsets of AIHA/Evans patients were significantly different, the expression levels of p-BTK in CD5+B cells were obviously higher than that in CD5-B cells, and higher than that in CD5+ B cells in CLL patients, and positively correlated with the number of serum IgE. Key words: anemia hemolytic autoimmune; Bruton's tyrosine kinase, Phosphorylated Bruton's tyrosine kinase; B cell subsets Disclosures No relevant conflicts of interest to declare.