Genetic analysis of complement component 9 (C9) polymorphisms with clearance of hepatitis B virus infection.

Abstract

BACKGROUND:

The complement component 9 (C9), a major cytolytic protein in the complement system, plays an important role in the immunological process. However, associations between genetic variations of the complement factor and chronic hepatitis B virus infection still need to be investigated.

AIMS:

We hypothesized that genetic variations in the complement component 9 gene can influence the clearance of chronic hepatitis B virus infection, hepatocellular carcinoma occurrence, and onset age of hepatocellular carcinoma. To investigate the relationship between complement component 9 variations and these disease phenotypes, we performed a case-control association analysis in a Korean population.

METHODS:

Genetic variations were identified through direct DNA sequencing and genotyped using TaqMan assay (n = 1,103). In order to investigate the relationship of complement component 9 with chronic hepatitis B virus clearance and hepatocellular carcinoma occurrence, differences in SNP and haplotype frequency distributions were analyzed using logistic and multiple regression analyses with adjusted age and gender as covariates.

RESULTS:

Although +23189C>T polymorphism in exon 4 and C9_ht2 [T-G-C-A-C] were significantly associated with clearance of chronic hepatitis B virus infection and hepatocellular carcinoma occurrence, the association signals were not retained after multiple testing corrections.

CONCLUSIONS:

We conclude that variations in the complement component 9 gene are unlikely to influence clearance of chronic hepatitis B virus infection and hepatocellular carcinoma occurrence. Although this preliminary result provides meaningful information, further functional investigations in other genetic factors for pathway analyses are required.

• Authors: Joon Seol Bae, Charisse Flerida A Pasaje, Byung Lae Park, Hyun Sub Cheong, Jeong-Hyun Kim, Tae Joon Park, Jason Yongha Kim, Jin Sol Lee, In Song Koh, Hyo-Suk Lee, Yoon Jun Kim, Hyoung Doo Shin
• Journal: Digestive diseases and sciences (Dig Dis Sci) Vol. 56 Issue 9 Pg. 2735-41 (Sep 2011) ISSN: 1573-2568 [Electronic] United States
• PMID: 21380615 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Complement C9

Topics

• Adult
• Aged
• Aged, 80 and over
• Alleles
• Complement C9 (genetics)
• Female
• Genetic Predisposition to Disease
• Genotype
• Hepatitis B (genetics)
• Humans
• Male
• Middle Aged
• Polymorphism, Genetic
• Promoter Regions, Genetic