ASSOCIATION OF DM GENES IN SYSTEMIC-SCLEROSIS IS SECONDARY TO THE ASSOCIATION WITH HLA GENES

The contribution of polymorphism of DMA and DMB alleles to the pathoge nesis of Japanese Systemic Sclerosis (SSc) was studied in 55 Japanese SSc patients and 77 normal Japanese subjects using the PCR-RFLP (restr iction fragment length polymorphism) method. The allele frequencies of DMB0101 allele were increased in SSc with diffuse scleroderma (70.0% vs 49.4%, p<0.05, pc=not significant (NS)) and in SSc with antitopois omerase I antibody (a-Scl-70), (68.2%, p<0.05, pc=NS). The phenotype f requencies of DMB0101 in these subgroups of SSc were increased signif icantly (95.0%, p=0.014, pc<0.05; 95.5%, p=0.0088, pc<0.05, respective ly). In contrast, DMB0102 and DMB*0103 alleles tended to decrease in diffuse scleroderma and SSc with a-Scl-70, but the decreases were not significant. Association analysis among DMA, DMB, and DRB11502 in Jap anese SSc with diffuse scleroderma and SSc with a-Scl-70 indicated tha t the increase in DMA0101 was not primary, but reflected an increase in KLA DRB11502.