The role of interleukin-10 promoter polymorphisms in primary Sjogren's syndrome

Objective: To determine the impact of a broad spectrum of different polymorphisms within the interleukin-10 (IL-10) promoter gene on disease susceptibility to primary Sjogren's syndrome (pSS), clinical manifestations, and autoantibody production. Methods: We genotyped 111 unrelated German Caucasian patients with pSS and 145 healthy controls for the single nucleotide polymorphisms (SNPs) at positions -2849, -2776, -2769, -2763, -1349, -1082, -851, -819, -657, and -592 and for the microsatellites IL10.R and IL10.G. Allele and haplotype distributions were compared between patients and controls and between subgroups of patients with different clinical and laboratory findings. Results: We found no significant differences in the allele or haplotype frequencies between pSS patients and healthy controls. After Bonferroni correction we found a significant association of the ACC haplotype (at the -1082, -819, and -592 loci) with immunoglobulin (Ig)A antibodies to anti--fodrin. Conclusion: Overall we found no associations of IL-10 promoter polymorphisms with the susceptibility to pSS in our cohort. The finding that the production of IgA anti--fodrin antibodies is associated with polymorphisms within the IL-10 promoter region suggests a genetic contribution to the generation of these antibodies.