Molecular analysis of major histocompatibility complex allelic associations with systemic lupus erythematosus in Taiwan

Objective. To investigate the association of HLA class II alleles/haplotypes, type I C2 deficiency gene, and tumor necrosis factor alpha gene promoter allele (TNF2) with systemic lupus erythematosus (SLE) in the Chinese population in Taiwan. Methods. The HLA-DRE1 and DQB1 alleles were studied in 105 SLE patients and 115 controls by the polymerase chain reaction (PCR)sequence-specific oligonucleotide probe method, the subtyping of DRB1*15/16 and DRB5 by PCR with sequence-specific primers, type I C2 deficiency gene by PCR, and TNF2 by PCR-Nco I restriction fragment length polymorphism. Results. The frequencies of the HLA class II alleles DRB1*02, DRB1*1502, DRB5*0102, DQB1*0501, and DQB1*0602 and DR2-associated haplotypes DRB1*1501, DRB5*0101, DQB1*0602 and DRB1*1502, DRB5*0102, DQB1*0501 were higher among SLE patients than among controls; however, only DQB1*0501 was statistically significantly associated with SLE, No specific allele/haplotype was significantly associated with lupus nephritis. No subject had type I C2 deficiency, SLE patients had a marginally higher percentage of TNF2, which was in linkage disequilibrium with DR3, Since DR3 was not associated with SLE in this Taiwanese Chinese population, TNF2 might play a role in the immunopathogenesis of SLE. Conclusion. Although no HLA-DRB1 allele was found to be significantly associated with SLE, the associations with DQB1*0501 and TNP2 suggest that DQB1 and tumor necrosis factor alpha mag be important genetic factors in SLE susceptibility in the Chinese population in Taiwan.