ASSOCIATION OF MANNOSE-BINDING LECTIN GENE HAPLOTYPE LXPA AND LYPB WITH INTERFERON-RESISTANT HEPATITIS-C VIRUS-INFECTION IN JAPANESE PATIENTS

Background/Aims: Mannose-binding lectin, a key factor of the innate im mune system, has genetic polymorphism, and individuals who carry certa in genotypes of mannose-binding lectin are known to be more prone to s evere or prolonged infectious diseases. We aimed to find any relevance of mannose-binding lectin polymorphism to hepatitis C virus infection . Methods: We determined the mannose-binding lectin genotypes by seque nce specific priming-polymerase chain reaction in 159 hepatitis C viru s-infected chronic hepatitis patients and 218 healthy controls in Japa n by looking at 4 polymorphic loci: 2 (H/L and X/Y) within the promote r region and 2 (P/Q and A/B) within exon-1 of the mannose-binding lect in gene. Results: A group of mannose-binding lectin genotypes designat ed ''XB-type'' (containing LXPA or LYPB haplotype at least heterozygou sly) was less frequently found in interferon-responsive patients (38.5 %) than in interferon-resistant patients (60.7%, p=0.008) and controls (57.3%, p=0.014). Individuals with the ''XB-type'' had lower serum co ncentrations of mannose-binding lectin, compared to those with ''YA-ty pe'', which is defined by homozygous carriage of both Y and A alleles: 0.63+/-0.61 vs 2.06+/-1.17 mg/l, p<0.001. Conclusions: Our results su ggest that the mannose-binding lectin-related innate immune system pla ys an important role in elimination of hepatitis C virus during interf eron therapy Determining mannose-binding lectin genotypes may help in selecting the hepatitis C virus-infected patients to be treated with i nterferon.