MICB0106 gene polymorphism is associated with ulcerative colitis in central China.
BACKGROUND
The highly polymorphic nonclassical MHC class I chain-related genes A and B (MICA and MICB) encode stress-inducible glycoproteins expressed on various epithelial cells including intestinal epithelial cells. MICA and MICB gene polymorphisms and expressions are associated with autoimmune diseases but not known in ulcerative colitis (UC).


OBJECTIVE
To investigate the association of MICB exon 2-4 polymorphisms and soluble MICA (sMICA) expression with the susceptibility of UC in central China.


METHODS
Genomic DNA was isolated from peripheral blood. The allele frequencies of MICB exon 2-4 were genotyped in 105 UC patients and 213 healthy controls by PCR single-stranded conformation polymorphism method. Thirty-two patients and 32 controls were selected for determining serum sMICA expression by ELISA.


RESULTS
Allele frequency of MICB0106 was significantly higher in UC patients than in healthy controls (19.0% vs. 8.9%, corrected P (Pc) = 0.0006), especially in patients with extensive colitis (24.4% vs. 8.9%, Pc = 0.0006), moderate and severe disease (24.1% vs. 8.9%, Pc = 0.0006), extraintestinal manifestations (20.5% vs. 8.9%, Pc = 0.012), male patients (22.1% vs. 8.0%, Pc = 0.006), and patients over the age of 40 years (28.8% vs. 8.3%, Pc = 0.0006). The sMICA level was significantly higher in UC than in healthy controls (604.41 +/- 480.43 pg/ml vs. 175.37 +/- 28.31 pg/ml, P = 0.0001) but not associated with the MICB0106 genotypes.


CONCLUSIONS
Overall, MICB0106 allele was positively associated with UC in the Han Chinese in central China. sMICA was highly expressed in UC but not associated with the MICB0106 genotype.
Li
Yi
Y
Department of Gastroenterology and Research Center of Digestive Diseases, Zhongnan Hospital, Wuhan University School of Medicine, Wuhan, People's Republic of China.
Xia
Bing
B
Lü
Min
M
Ge
Liuqing
L
Zhang
Xiaolian
X
D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D003093:Colitis, Ulcerative / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005091:Exons; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D015395:Histocompatibility Antigens Class I / Q000097:blood / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; C098080:MICB antigen