Overall, the IL-21 rs6822844 G/T polymorphism was found to be significantly associated with decreased RA risk (eg: T-allel</span>e vs. G-allele: OR= 0.81, 95% CI= 0.72-0.91, P < 0.001).
This study indicates for the first time that there is a strong association between IL2/IL21 rs6822844 variant and susceptibility to RA in the Algerian population, and that this association was independent from the autoantibodies status of RA patients.
When combined in a meta-analysis using data from a total of 9,772 cases and 10,909 controls there was a genome-wide level of significance supporting association of rs6822844 with RA (OR=0.86 (0.82 to 0.91), P=8.8x10(-8), P=2.1x10(-8) including North American Rheumatoid Arthritis Consortium data).
We detected significant associations of rs6822844 with SLE (P = 0.008), type 1 DM (P = 0.014), RA (P = 0.019), and primary SS (P = 0.033) but not with BD (P = 0.34) or CD (P = 0.98).
We tested SNP rs6822844 for association with disease in 350 T1D-affected and 1,047 rheumatoid arthritis (RA)-affected Dutch patients and in 929 controls.