HLA class II alleles in Japanese patients with inflammatory bowel disease

The association of various HLA class II loci with Crohn's disease (CD) and ulcerative colitis (UC) has yet to be fully elucidated. To determine whethe r then is an association of HLA class II genes (DR, DQ and DP alleles) with inflammatory bowel disease (IBD), HLA class II genes for polymorphisms wer e analyzed at the DNA level in 111 patients with CD, 81 with UC and 525 hea lthy controls by the polymerase chain reaction-sequence specific oligonucle otide probe method. Allele and haplotype frequencies were compared between these populations Results were as follows: 1) the presence of DQB1*0402 (RR =3.90, P-c=0.0001) was positively associated with CD; 2) the presence of DR B1*1502 (RR= 4.51, P-c<1x10(-8)), DRB5*0102 (RR= 4.70, P-c<1x10(-8)), DQA1* 0103 (RR=3.72, P-c=1x10(-5)), DRB1*06011 (RR=3.78, P-c=1x10(-4), DPA1*0301 (RR=3.23, P-c=0.0001) and DPB1*0901 (RR=4.83, P-c<1x10-8) was positively as sociated and that of DRBA*0101B1 (RR=0.20, P-c<1x10(-8)) and DQA1*0302 (RR= 0.34, P-c=0.001) negatively associated with UC; 3) haplotype analysis showe d a positive association between the presence of DRB1*0410-DQA1*0302-DQB1*0 402 and DRB1*0802 DQA1*0401-DQB1*0402 with CD, and a negative association b etween the presence of DRB1*1502-DQA1*0103-DQB1*06011 and CD, there was no association of DRB1*08032 DQA1*0103-DQB1*06011 with CD; and 4) in UC, a pos itive association with the presence of DRB1*1502-DQA1*0103- was found, but DRB1*C08032-DQA1*0103-DQB1*06011 was not associated with it. In conclusion, in CD in the Japanese population, HLA linked disease susceptibility allele s appear to he DQB1*0402 and DRB1*1502, a disease resistance allele. In UC, DRB1*1502 appears to be a disease susceptibility allele.