ANALYSIS OF MHC CLASS-II DP, DQ AND DR ALLELES IN CROHNS-DISEASE

Background-Although inflammation in Crohn's disease is believed to be mediated by activated T cells, genotyping of all MHC class II alleles in white people with this disease has not been reported. Aims-To perfo rm a detailed molecular analysis of HLA DPB, DQB, and DRB genes in whi te patients with Crohn's disease and controls in order to determine if the inheritance of any class II genes confers susceptibility or resis tance to this disease. Methods-Complete molecular typing of HLA class II DPB, DQB, and DRB alleles was performed in 58 white patients with C rohn's disease and 93 healthy controls using a polymerase chain reacti on-sequence specific oligonucleotide based approach. Results-No signif icant association with any DPB or DQB alleles was noted in patients wi th Crohn's disease. Since our previous studies had shown a strong asso ciation of an HLA DRB3(star)0301/DRB1(star)1302 haplotype with Crohn's disease, we re-examined this association using more stringent genotyp ing criteria. This haplotype was present in 20.7% of patients and 5.4% of controls (p = 0.0066; relative risk = 4.59). Conclusions-The DRB3( star)0301/DRB1(star)1302 haplotype is the only significant MHC class I I association noted in white people with Crohn's disease and represent s the strongest association of any MHC or non-MHC locus with this dise ase.