To systematically review evidence regarding the relationship between circulating interleukin-17 (IL-17) levels and rheumatoid arthritis (RA), and associations between polymorphisms in IL-17 genes and RA susceptibility.
We performed a meta-analysis of serum/plasma IL-17 levels in patients with RA and controls, and evaluated evidence of associations between the rs2275913, rs3819024, rs4711998 and rs8193036 polymorphisms in 
Fourteen studies including 3118 patients with RA and 2725 controls were included. Our meta-analysis revealed that IL-17 levels were significantly higher in the RA group than in the control group (p=3.1×10
Our meta-analysis revealed significantly higher circulating IL-17 levels in patients with RA, and found evidence of associations between the 