Objective: To investigate the association between the exon 2, 3, 4 of MHC class I chain-related gene-B (MICB) and ulcerative colitis (UC) in Chinese Han.
Methods: Using polymerase chain reaction single-stranded conformation polymorphism, allele frequency of MICB exon 2, 3 and 4 in 105 patients with UC and 213 age and sex matched healthy controls were genotyped. All of the studied individuals were Chinese Han.
Results: Allele frequency of MICB 0106 was increased in patients with UC as compared with normal controls (19.0% vs 8.9%, P = 0.000, Pc < 0.001, OR = 2.402, 95% CI: 1.488-3.879). The frequency of MICB 0106 was increased significantly in patients with extensive colitis (24.4% vs 8.9%, P = 0.000, Pc < 0.001, OR = 3.294, 95% CI: 1.800-6.027), moderate and severe disease (24.1% vs 8.9%, P = 0.000, Pc < 0.001, OR = 3.294, 95% CI: 1.893-5.576) and in those with extra intestinal manifestations (20.5% vs 8.9%, P = 0.002, Pc = 0.012, OR = 2.626, 95% CI: 1. 18 4. 61). Furthermore, MICB 0106 allele was higher in frequency in the male patients with UC (22. % vs 8. % P = 0. 01, Pc =0 . 06, OR =3 . 76, 95% CI:1 . 37 6. 78) and the patients more than4 0 years old (28.8% vs 8.3% P = 0.000, Pc <0 .001, OR= 4 .500, 95% I:2 . 81 8.504) as compared with healthy controls.
Conclusion: MICB 0106 allele is positively associated with UC, especially with extensive colitis, moderate and severe disease, presence of extra intestinal manifestations, male gender and age of more than 40 years in Chinese Han in Hubei province.