Expression of TRAF6 in peripheral blood B cells of patients with myasthenia gravis

Abstract

Abstract Background Tumor necrosis factor receptor-associated factor 6 (TRAF6) can regulate the activation of inflammatory signaling pathways by acting as an E3 ubiquitin ligase, which enhances B cell activation. This study aimed to evaluate the expression of TRAF6 in the peripheral blood B cells of myasthenia gravis (MG) patients and analyze the relationships between TRAF6 expression and clinical characteristics. Method In our study, the expression level of TRAF6 in peripheral blood B cells of 89 patients was measured by flow cytometry compared with that of healthy subjects. The effects of disease severity, MG classification and immunotherapy on TRAF6 expression level were also analyzed. Results In our study, TRAF6 expression was elevated in CD19+ B cells and CD19+CD27+ memory B cells in generalized MG (GMG) patients compared with ocular MG (OMG) patients (p = 0.03 and p = 0.03, respectively). There was a significant positive correlation between the TRAF6 expression level and disease severity in both OMG patients and GMG patients (CD19+ B cells: OMG: p < 0.001, r = 0.89; GMG: p = 0.001, r = 0.59; CD29+CD27+ B cells: OMG: p = 0.001, r = 0.80; GMG: p = 0.048, r = 0.38). TRAF6 expression was significantly elevated in CD19+ B cells and CD19+CD27+ memory B cells in GMG with acute aggravation compared with GMG in MMS (p = 0.009 and p = 0.028, respectively). In the eleven MG patients who were followed, TRAF6 expression in B cells and memory B cells was significantly decreased after treatment (p = 0.03 and p < 0.01, respectively). Conclusion TRAF6 is potentially a useful biomarker of inflammation in patients with MG, and might be used to evaluate the effectiveness of treatment.

Keywords

• Myasthenia gravis
• Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6)
• B cell
• Memory B cell
• ADL-score