Clinical feature and serum markers in patients with myasthenia gravis and connective tissue disorder

Background: The coexistence of myasthenia gravis (MG) and connective tissue disorder (CTD) disease is rarely reported and until now few published studies have been found on MG-CTD disease. In this study we aimed to investigate the clinical features of MG-CTD patients and explore the relationship between the expression level of several serum factors and clinical features of MG-CTD patients. Methods: 24 patients diagnosed with MG-CTD syndrome were collected in our study. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the expression levels of serum factors including IL-17, IL-23, PTP, PTK, AChR-Ab, and MuSK-Ab. In addition, the difference of expression levels of serum factors in patients and control groups was analyzed by T test. Chi-squared test was used to analyze the relationship between serum factors and clinical features. Results: The results indicated that the expression of serum factors including IL-17, IL-23, PTP and AChR-Ab were significantly increased in MG-CTD patients compared to the normal control group (P<0.05). Moreover, the outcome showed that the serum factor were closely related with clinical features, as IL-23 positive expression affecting Thymectomy (P=0.006, OR=0.063, 95% CI=0.007-0.590), and AChR-Ab affecting CTD type (P=0.019, OR=0.111, 95% CI=0.016-0.789) and Thymectomy (P=0.003, OR=0.040, 95% CI=0.003-0.477). Conclusion: Several serum factors showed increased expression levels in MG-CTD patients and the factors might be potential useful serum markers for MG-CTD.