Significance of HLA-B[*]51 allele expression in Crohn's disease: a case-control study.

OBJECTIVES: Crohn's disease (CD) and Behcet's disease (BD) are two autoinflammatory diseases that share clinical and pathogenic features. Furthermore, when BD involves the gastrointestinal tract, it is extremely difficult to distinguish endoscopic lesions from CD lesions. HLA-B*51 allele expression is highly associated with BD diagnosis. In this study we analysed HLA-B*51 status in 70 Argentine patients with confirmed CD diagnosis and compared it to our previous Argentine BD cohort, with the aim of finding similarities or differences between these two diseases regarding HLA-B*51 status. METHODS: This is a multi-centre case-control study, including 70 patients with confirmed CD diagnosis, who underwent HLA-B*51 allele status testing; the results were compared to our previous BD cohort of 34 patients. RESULTS: Among patients with CD, 12.85% were positive for the HLA-B*51 allele, compared with 38.24% patients with BD (OR=0.238; 95% CI=0.089-0.637; p=0.004). CONCLUSIONS: Our finding suggests that determination of HLA-B*51 allele status may contribute to the differential diagnosis between CD and BD.