Molecularly defined HLA-DR2 alleles in ulcerative colitis and an antineutrophil cytoplasmic antibody-positive subgroup.

ABSTRACT

BACKGROUND/AIMS: Although HLA-DR2 is associated with Japanese ulcerative colitis, data regarding an HLA-DR2 association in other populations are conflicting. A recent study suggests that HLA-DR2 is only associated with antineutrophil cytoplasmic antibody-positive ulcerative colitis. The aim of this study was to determine whether HLA-DR2 or the molecularly defined alleles within the HLA-DR2 group are associated with ulcerative colitis or a perinuclear antineutrophil cytoplasmic antibody-positive subgroup. METHODS: Unrelated white patients with a history of ulcerative colitis (n = 97) and control subjects matched to patients for Jewish ethnicity and sex (n = 149) were studied. An immunofluorescence assay was used to detect perinuclear antineutrophil cytoplasmic antibodies. A molecular, DNA-based method was used to perform HLA-DR2 typing. RESULTS: HLA-DRB1*1601 was present in 11 of 149 controls and 1 of 97 patients (P = 0.031, corrected P, not significant; Fisher's Exact Test). There were no other significant differences between ulcerative colitis or ulcerative colitis stratified by perinuclear antineutrophil cytoplasmic antibody status and controls. CONCLUSIONS: The HLA-DR2 group of alleles is not associated with ulcerative colitis or a perinuclear antineutrophil cytoplasmic antibody-positive subgroup. The unexpected finding of a decreased frequency of HLA-DRB1*1601 in ulcerative colitis should be further investigated.