title: Mannose-binding lectin in chronic hepatitis B virus infection.
abstract: Mannose binding lectin (MBL) is a pattern-recognition molecule of the innate immune system. The roles of MBL and its gene (mbl2) polymorphisms, -221X/Y and codon 54A/B, in hepatitis B virus (HBV) infection were investigated in this study. We recruited 320 nonprogressed hepatitis B surface antigen (HBsAg) carriers; 199 progressed HBsAg carriers with hepatocellular carcinoma or cirrhosis; 87 spontaneously recovered individuals who were HBsAg negative and anti-HBs and anti HBc positive; and 484 controls who were naïve to HBV. There was no significant difference between nonprogressed carriers, spontaneously recovered individuals, and controls in terms of serum MBL levels and mbl2 polymorphisms distributions. However, the low MBL genotypes had a dose-dependent correlation with the cirrhosis and hepatocellular carcinoma in progressed carriers with odds ratios of 1.36 and 3.21 for the low and extremely low MBL genotypes, respectively (P = .01). The low-expression promoter haplotype XA (OR = 1.97) and the mutant haplotype YB (OR = 1.90) were also associated with the cirrhosis and hepatocellular carcinoma (P = .002). As expected, the lower serum MBL levels in progressed carriers as compared with nonprogressed carriers were due to an overrepresentation of low and extremely low MBL genotypes. Moreover, MBL could bind HBsAg in a dose- and calcium-dependent and mannan-inhibitable manner in vitro, suggesting that binding occurs via the carbohydrate recognition domains. This binding also enhanced C4 deposition. In conclusion, these results suggest that low MBL genotypes associate with the occurrence of cirrhosis and hepatocellular carcinoma in progressed HBsAg carriers, and MBL can bind HBsAg.
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Hong Kong Jockey Club Clinical Research Centre, Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
authors.forename: Wai Po
authors.initials: WP
authors.lastname: Chong
authors.forename: Yuk Fai
authors.initials: YF
authors.lastname: To
authors.forename: Wai Kee
authors.initials: WK
authors.lastname: Ip
authors.forename: Man Fung
authors.initials: MF
authors.lastname: Yuen
authors.forename: Tung Ping
authors.initials: TP
authors.lastname: Poon
authors.forename: Wilfred H S
authors.initials: WH
authors.lastname: Wong
authors.forename: Ching Lung
authors.initials: CL
authors.lastname: Lai
authors.forename: Yu Lung
authors.initials: YL
authors.lastname: Lau
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003062:Codon; D003181:Complement C4 / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000378:metabolism; D019694:Hepatitis B, Chronic / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D008103:Liver Cirrhosis / Q000235:genetics; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D011110:Polymorphism, Genetic
chemical_list: D003062:Codon; D003181:Complement C4; D006514:Hepatitis B Surface Antigens; C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin