The Role Of IL-27 In Myasthenia Gravis And Its Correlation With Anti-AchR-IgG Class Switching

Objective:This study is aimed to investigate the role of IL-27 in the pathogenesis of myasthenia gravis by detecting the serum concentration of IL-27,the expression of IL-27 receptor subunit WSX-1 mRNA in both of PBMC and B lymphocytes,measuring the serum level of anti-AchR-IgG and it's isotype in MG patients,analyzing the relationship between these results,so as to offer a theoretical basis of the targeted therapy with IL-27.Methods:44 MG patients and 22 healthy controls were investigated by retrospective study.The PBMCs was extraced from the peripheral blood,and the B cell was extraced by immunomagnetic beads. The mRNA expressions of WSX-1 on PBMCs and on B cells were detected by RT-PCR,the serum concentrations of IL-27 and the levels of anti-AchR-IgG and it's isotype IgG₁,IgG₂,IgG₃were tested by ELISA, and the correlation among them were analyzed.Results:(1)The concentration of IL-27 in serum of MG group was higher than that of control group(28.09±6.41pg/ml VS 25.67±4.03pg/ml) and the difference were significant(p＜0.05), however,there was no significant difference between ocular MG subgroup and generalised MG subgroup(27.41±6.65 pg/ml VS 29.27±6.22 pg/ml,p＞0.05).(2) The relative OD values of WSX-1 mRNA on PBMCs of MG group was higher than that of control group (0.736±0.176 VS 0.539±0.267),and the differences were significant(p＜0.05);But,among the MG group,the different of relative OD values of WSX-1 mRNA between ocular MG group and generalised MG group (0.705±0.198 VS 0.778±0.447) was no significant(p＞0.05).(3) The concentration of IL-27 in serum was positive correlation with the level of anti-AchR-IgG(p＜0.05),but was not significant correlation with the levels of anti-AchR IgG₁,IgG₂,IgG₃ isotype(p＞0.05).(4)In anti-AchR-Ab positive MG subgroup,the relative OD values of WSX-1 mRNA on PBMCs was not significant correlation with the levels of the anti-AchR-IgG and it's isotypes IgG₁,IgG₂,IgG₃(p＞0.05), However the relative OD values of WSX-1 mRNA on B cell was positive significant correlation with levels of the anti-AchR-IgG and it's IgG₁ isotype(p＜0.05,p＜0.01),but was not significant correlation with it's IgG₂and IgG₃ isotype(p＞0.05).Conclusions:IL-27 may encourage the class switch of anti-AChR antibodies to anti-AchR-IgG₁ in the peripheral blood of MG patients through the IL-27 receptor on B cells,which may play an important role in MG invasion.