The DRB1/3/4/5 loci from 97 patients with MS and 100 normal control subject
s were analyzed. DRB1*15 increased the risk of MS (OR = 4.2, p < 0.0001), w
hereas DR1 decreased the risk (OR = 0.30, p(c) = 0.005). In analyses of the
DR1 risk in relation to DR51, DR52, and DR53 alleles, DR1 in combination w
ith DR53 was found to have the strongest protective effect against MS in al
l subjects (OR = 0.05, p < 0.0001) and in DRB1*15-negative subjects (OR = 0
.09, p(c) = 0.026). DR53 may be an important allele or haplotype, acting to
gether with DR1 to protect against MS.