RESEARCH ARTICLE Putative IL-10 Low Producer Genotypes Are Associated with a Favourable Etanercept Response in Patients with Rheumatoid Arthritis

Outcome predictors of biologic therapeutic drugs like TNF inhibitors are of interest since side effects like serious infections or malignancy cannot be completely ruled out. Response rates are heterogeneous. The present study addressed the question whether in patients with rheumatoid arthritis (RA) interleukin-10 (IL-10) promoter genotypes with potential rele-vance for IL-10 production capacity are associated with response to long-term treatment with etanercept. Caucasian RA patients that, according to the EULAR criteria, responded well (n = 25), moderately (n = 17) or not (n = 8) to etanercept therapy (median 36 months, range 4–52), and 160 matched controls were genotyped for the IL-10 promoter SNPs-2849 G>A (rs6703630),-1082 G>A (rs1800896),-819 C>T (rs1800871) and-592 C>A (rs1800872). Haplotypes were reconstructed via mathematic model and tested for associa-tions with disease susceptibility and therapy response. We identified the four predominan