Correlation between interleukin-34 (IL-34) levels and inflammation in rheumatoid arthritis (RA) patients. (A) IL-34 levels were determined in plasma of healthy controls (normal), OA or RA patients by n enzyme-linked immunosorbent assay (ELISA) (*P < 0.05, N.S., not significant, compared to normal). (B) and (C) Plasma was collected from individual RA patients (n = 10) and the same patients were administrated disease-modifying anti-rheumatic drugs (DMARDs) and followed-up for 1 year. Disease Activity Score 28 (DAS28) activity (A) and IL-34 levels (ELISA) (B) were determined for each patient in plasma samples collected before and after administration of DMARDs. Symbols indicate individual data points; horizontal bars show group means (P < 0.01, after versus before DMARDs administration).
Hwang et al. Arthritis Research & Therapy 2012 14:R14 doi:10.1186/ar3693