Patients
Two ACPA+ and two ACPA- RA patients from Peking University Third Hospital who fulfilled the 2010 European League Against Rheumatism/American College of Rheumatology classification criteria for RA(2) were enrolled in the study. All 4 patients were newly diagnosed, treatment naive, menopausal, and non-smoker women from the northern Han population with symptom duration of less than 6 months, and none had any other chronic diseases. Three matched healthy individuals were included in the study.
PBMC collected from 40 ACPA+, 40 ACPA- RA patients, and 40 healthy controls were applied for quantitative PCR to validate candidate genes expression. Serum CXCL2 levels were detected by ELISA in a cohort consisted of 70 ACPA+, 37 ACPA- RA patients, and 40 healthy controls. The clinical and laboratory data of the patients were collected from electronic medical records. In all comparisons mentioned, the groups were age and sex matched. The present study was conducted in accordance with the Declaration of Helsinki. The Ethics Committee of Peking University Third Hospital approved the study. All procedures involving specimens obtained from humans were performed with informed consent from each patient.