V. Taneja et al., POLYMORPHISM OF HLA-DRB, HLA-DQA1, AND HLA-DQA1 IN RHEUMATOID-ARTHRITIS IN ASIAN INDIANS - ASSOCIATION WITH DRB1-ASTERISK-0405 AND DRB1-ASTERISK-1001, Human immunology, 46(1), 1996, pp. 35-41
We investigated the DRB, DQA1, and DQB1 polymorphism and haplotypes in
sporadic and familial RA subjects of Asian Indian origin by PCR oligo
typing using biotinylated SSOPs. Molecular subtyping of DRB104 in RA
patients showed strongest association with highest relative risk with
DRB10405, followed by DRB1*0401. A significant decreased frequency of
DRB11502 was observed in patients compared to controls (chi(2) = 4.5
). Among other alleles, DRB1001 was found to be significantly increas
ed. A total of 73.3% of patients carried the shared sequence of the th
ird HVR (67-74) of DRB1 domain compared to its presence in only 37.6%
of controls. A significant number of patients carried DR4 haplotypes o
n DQB10302 (58%) as against loci. DQB1*0301 which was present only on
10.5% of the haplotypes. When compared to controls, the difference wa
s significant for the latter allele only. Few unique DR-DQ haplotypes
were observed in Asian Indians. Among DR-DQ haplotypes, DRB10401-DQB1
0302 gave the highest risk whereas DRB1*0403-DQB1*0301 was negatively
associated. Alleles with negative charge at position 70 confer protec
tion or are negatively associated with RA whereas among the associated
alleles, glycine at position 86 resulted in higher risk than those wi
th valine at this position. A heterogenous association of DQB1 alleles
with DR4 subtypes, influencing susceptibility to RA, suggests the DQB
locus is not primarily associated with RA and susceptibility lies in
the sequence 67-74 of the DRB1 loci.