The Correlation Of S-Formylglutathione Hydrolase With Rheumatoid Arthritis

Rheumatoid arthritis(RA) is defined as a systemic autoimmune disorder and a recurring disease that bothers lots of people. In clinic, RA is featured with death, disability, discomfort, dollar costs and drug toxicity. If it is not diagnosed early and treated properly, it may cause various complications which implicate other important organs except for joints and may threaten the life of patients. Unfortunately, the current clinical sciences do not have a very definite and complete understanding about its pathological mechanism. This makes the disease sometimes misdiagnosed in the early stage. Therefore, there is a clear clinical need for early and valid diagnosis index with high specificity and sensitivity. To identify new specific diagnostic markers could provides not only new possible diagnosis tool but also potential new target for clinical intervention.To identify new autoantigen of RA, we got protein profile of serum from RA patients by using two-dimensional gel electrophoresis. By comparison with western blot with RA patient’s and the healthy’s serum, we identified S-formylglutathione hydrolase(EsD) is high expression of RA patients and low expression of healthy individuals. Next, we tested levels of EsD in the serum of patients with early RA, late RA, non-RA(other autoimmune disease) and healthy individual by ELISA. We found that EsD is specifically elevated in the serum of early RA and late RA patients but not in non-RA diseases and healthy, indicating EsD is a potential marker for diagnosis of RA. Thirdly, we investigated the relationship of EsD with currently available RA markers in a cohort of patients. We found that Es D levels in serum were significantly correlated with ESR, CCP and DAS28 score(P<0.05), but exhibited no significant correlation with RF(P>0.05), indicating expression level of Es D is positively correlated with activity of RA. In the end, eight patients receiving steroids treatment or not were selected for analysis and it was found that Es D was negatively correlated with response after treatment, demonstrating possible application of EsD as a marker for evaluation of treatment efficacy.In conclusion, we find EsD is a potential autoantigen for RA by two-dimensional gel electrophoresis and MALDI-TOF-MS. Because EsD is of high concentration in serum of patients with early RA and correlated with erythrocyte sedimentation rate(ESR), anti-cyclic peptide containing citrulline(CCP)and disease activity score in 28 joints(DAS28), it is a possible diagnostic marker for early RA. The negative correlation of EsD with steroids therapy treatment demonstrated it reflects the activity of illness. However, the diagnostic value of serum Es D for early RA requires larger cohort validation, and the role of EsD in the pathogenesis of RA needs further elucidation in the future.