Interleukin-10 (IL-10) signaling has been suggested to play a role in systemic sclerosis (SSc). IL10RB codes for IL-10 receptor 2 (IL-10R2), a component shared in receptor complexes for IL-10, IL-22, IL-26 and interferon (IFN)-gamma. In this study, we examined association of IL10RB polymorphism with susceptibility to SSc. Genotype A/A at rs2834167 (47K/K) was significantly increased in diffuse cutaneous SSc (dcSSc) (41.3% in dcSSc, 20.9% in controls, P= 0.0018, odds ratio = 2.67). A SNP in the 5' flanking region of IL10RB, rs999788, also showed association with dcSSc; however, this association was shown to be secondarily caused by linkage disequilibrium with rs2834167. Significant association was not observed in limited cutaneous SSc (1cSSc). Presence of anti-topoisomerase I antibody was also associated with rs2834167A/A genotype (P=0.0019). Serum IL-10 level was significantly associated with the number of rs2834167A allele (P=0.007). These findings suggested that signaling through IL-10R2 may play a causative role in dcSSc. (c) 2008 Elsevier Inc. All rights reserved.