FOXP1在重症肌无力患者外周血B 淋巴细胞中的表达和临床意义

Expression and clinical significance of FOXP1 in peripheral blood B lymphcytes of patients with myasthenia gravis

目的：探讨重症肌无力（ MG）患者外周血B淋巴细胞中叉头框蛋白P1（ FOXP1） mRNA表达水平和临床意义。方法收集34例MG患者及24例健康体检者（健康对照组）的静脉血样，并根据MG患者病情程度将其分为眼肌型重症肌无力（ OMG）组和全身型重症肌无力（ GMG）组，根据定量重症肌无力（ QMG）量表评分。荧光实时定量PCR检测CD19＋B细胞中FOXP1 mRNA的表达水平，流式细胞术检测外周血中CD138＋浆细胞的表达频率，间接ELISA法检测血清IgG型抗乙酰胆碱受体（ AChR）抗体滴度。分析OMG组和GMG组CD19＋B细胞中FOXP1 mRNA的表达水平与QMG评分、CD138＋浆细胞频率、抗AChR抗体滴度的相关性。结果与健康对照组相比，OMG组和GMG组外周血CD19＋B细胞中FOXP1 mRNA表达水平均降低，抗AChR抗体滴度均增加，差异有统计学意义（P＜0．01），且GMG组变化较OMG组更为显著（P＜0．01）。 OMG组和GMG组外周血CD19＋B细胞中FOXP1 mRNA的表达水平与QMG评分、CD138＋浆细胞频率、抗AChR滴度均呈显著负相关。结论FOXP1在MG患者B细胞中表达减少，与临床严重程度及浆细胞频率负相关，提示FOXP1可能在B细胞向浆细胞分化中发挥负调控作用。

Objective To detect the level of FOXP1 mRNA in peripheral blood B lymphocytes of patients with my-asthenia gravis （ MG） and to explore the clinical significance of FOXP 1 in MG.Methods A total of 34 MG patients and 24 healthy subjects （ a control group ） were included into the current study .The MG patients were sub -divided into two groups：an ocular myasthenia gravis （ OMG） group and a general myasthenia gravis （ GMG） group.Both the QMG and GMG groups were scored using the quantitative MG （QMG） scale.The level of FOXP1 mRNA in CD19 ＋B cells was de-termined by quantitative real -time PCR.The frequencies of CD138 ＋plasma cells were detected by flow cytometry .The titers of anti-acetylcholine receptor （AchR）-IgG were tested by ELISA.Meanwhile, the associations between the level of FOXP1 mRNA in CD19 ＋B cells in the OMG and GMG groups and QMG scores , the frequencies of CD 138 ＋plasma cells and the titers of anti -AchR-IgG were analyzed .Results Compared with the control group , the OMG and GMG groups produced reduced levels of FOXP 1 mRNA in CD19 ＋B cells, increased frequencies of CD 138 ＋plasma cells and higher anti-AchR-IgG titers （each P〈0.01）.Meanwhile, the changes in the GMG group was more remarkable than those in the OMG group （each P〈0.01）.The level of FOXP1 mRNA in CD19 ＋B cells was negatively associated with QMG scores, CD138 ＋plasma cell frequency and anti -AchR -IgG titers.Conclusion The decreased expression of FOXP1 mRNA in B cells of MG patients is negatively associated with clinical severity and plasma cell frequency , indica-ting the potential role of FOXP 1 in negative regulation of the differentiation of B cells into plasma cells in the pathogenesis of MG.