Although the cause of Sjögren's syndrome remains unknown, many arguments suggest a role for both environmental and genetic factors. An association with HLA molecules has been established. Other genes on the short arm of chromosome 6 may be involved, most notably the TNF gene, which may be pivotal in the development of the epithelial lesions.
We investigated TNFalpha microsatellites in 35 patients with primary Sjogren's syndrome and in 146 healthy controls.
The frequency of the TNFalpha10 allele showed a non-significant increase in the Sjögren's disease group (28.6% vs 15.8%; P = NS). We found significant increases when we considered only those Sjögren's disease patients with joint manifestations (N = 24; 37.5% vs 15.7%; P < 0.05) or only those with anti-Ro(SSA) antibodies (N = 10; 50% vs 15.7%; P < 0.05).
Our data support a role for the TNFalpha10 allele in primary Sjögren's syndrome, particularly those forms with joint symptoms and anti-Ro(SS-A) antibodies.