Tumor necrosis factor receptor-associated factor 6 (TRAF6) may be a potentially useful biomarker of inflammation and treatment effectiveness in patients with myasthenia gravis (MG), according to a study published in BMC Neurology.
Expression levels of TRAF6 were found to be elevated in CD19+ B cells and CD19+CD27+ memory B cells in patients with MG during the study, and the upregulated expression was significantly associated with the severity of MG. A significant decrease in TRAF6 levels was observed in patients after treatment with immunotherapy.
Compared to healthy controls, TRAF6 levels were significantly higher in CD19+ B cells and CD19+27+ memory B cells in patients with MG (P <.001 for both cell types). TRAF6 expression was also found to be greater in patients with generalized MG (GMG) than in those with ocular MG (OMG) (P =.03 for both cell types).
An increasing trend was observed in TRAF6 expression from MG Foundation of America classification class I to class IV, although this trend was not significant, possibly due to the small number of patients with class IV. No correlations were found between TRAF6 expression and sex, age, age at onset, or the presence of thymoma.
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A significant positive correlation was observed between TRAF6 expression and MG Activities of Daily Living (MG-ADL) score. This relationship was observed in both patients with OMG and those with GMG with acute aggravation.
“A strong relationship between the TRAF6 expression in B cells and ADL score was identified, indicating that the TRAF6 expression level in CD19+ B cells was closely related to the severity of MG and might be an indicator for predicting disease severity,” the authors said.
During the study, 11 patients with acute aggravation before immunotherapy were followed, and blood samples were collected again when the patients reached the minimal manifestation state (MMS) after immunotherapy. A significant decrease was observed in both CD19+ B cells (2.30 vs 0.40) and CD19+CD27+ memory B cells (1.71 vs 0.56).
“Our study is limited by the [comparison] of MG patients before and after immunotherapy in one center. In addition, the sample size of the study was small. Whether the effect of immunosuppressive therapy on TRAF6 is directly related to MG regression will require further study,” the authors said.
The study enrolled 89 MG patients and 43 healthy controls at a single clinical site in China. Acute aggravation was observed in 42 patients, 14 with OMG and 28 with GMG. MMS was ultimately achieved in 58 patients.
Li T, Li Y, Li JW, et al. Expression of TRAF6 in peripheral blood B cells of patients with myasthenia gravis. BMC Neurol. 2022;22:302. doi:10.1186/s12883-022-02833-9