[The relationship between major histocompatibility complex class I chain-related antigens A (MICA)-129 gene polymorphism, soluble MICA level and ulcerative colitis].

OBJECTIVE

To investigate the association of the major histocompatibility complex class I chain-related antigens A (MICA)-129 gene polymorphism and soluble MICA (sMICA) levels with ulcerative colitis (UC) in Hubei Han nationality.

METHODS

The genetic polymorphism of MICA-129 was examined using a polymerase chain reaction-sequence based test (PCR-SBT) in 256 UC patients and 460 healthy controls. From the above subjects, 80 patients and 90 healthy individuals were randomly selected for determining serum sMICA concentrations by ELISA.

RESULTS

The frequencies of variant allele (G) and genotype (GG) in MICA-129 gene were significantly higher in the UC patients than in the controls (76.8% vs 72.2%, P = 0.060; 55.9% vs 46.3%, P = 0.016). Serum sMICA levels were significantly elevated in the patients compared to the controls [(576.47 ± 279.02) ng/L vs (182.17 ± 73.11) ng/L, P < 0.001]. In addition, the sMICA levels were higher in the patients carrying MICA-129 GG genotypes than in those carrying (GA + AA) genotypes [(638.87 ± 347.15) ng/L vs (507.51 ± 152.87) ng/L, P = 0.035].

CONCLUSIONS

The genetic polymorphism of MICA-129 and sMICA levels are correlated with the UC patients in Hubei Han nationality. Our findings demonstrate that MICA-129 gene may contribute to the pathogenesis of UC.