HSP70 GENE POLYMORPHISMS IN ANKYLOSING-SPONDYLITIS

Despite the strength of the association of ankylosing spondylitis (AS) with HLA B27, other genetic elements could play a possible role in th e pathophysiology of AS. Because of the localization, in the proximity of the HLA-B locus, and the involvement of heat shock proteins (HSP) in the immune response, we analyzed the influence of HSP70 gene polymo rphism on the susceptibility to AS. HSP70-1, HSP70-2 and HSP70-hom gen otypes were analyzed by PCR-RFLP in patients with AS and in healthy co ntrols. The results obtained in the present study showed that there ar e not significant differences in the distribution of HSP70-hom genotyp es, whereas significant differences in HSP70-1 and HSP70-2 genotypes b etween AS patients and random controls were found. However, when the d istribution of these genotypes were compared in B27-matched AS patien ts and controls, the differences disappeared. These data suggest that the polymorphism of HSP70 genes was not independently associated with AS, and that the differences in HSP70-1 and HSP70-2 genotypes among AS patients and controls appears to be due to the linkage disequilibrium between HSP70 alleles and HLA-B27.