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Published on: December 15, 2023
Association between TLR7 copy number variations and hepatitis B virus infection outcome in Chinese
Fang Li1, Xu Li1, Gui-Zhou Zou1
1Fang Li, Gui-Zhou Zou, Yu-Feng Gao, Jun Ye, Department of Infectious Disease, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601, Anhui Province, China.
Insights
Low copy number of toll-like receptor 7 (TLR7) is a significant risk factor for developing chronic hepatitis B virus (HBV) infection in both males and females. This genetic variation does not influence disease progression to cirrhosis or cancer.
Area of Science:
- Immunogenetics
- Hepatology
- Virology
Background:
- Hepatitis B virus (HBV) infection poses a significant global health burden.
- Toll-like receptor 7 (TLR7) plays a crucial role in innate immune responses.
- Genetic variations, such as copy number variations (CNVs), may influence susceptibility to viral infections.
Purpose of the Study:
- To investigate the association between TLR7 gene copy number variations (CNVs) and the susceptibility to chronic HBV infection.
- To determine if TLR7 CNVs correlate with disease progression in chronic hepatitis B patients.
Main Methods:
- Case-control study involving 623 chronic hepatitis B (CHB) patients and 300 acute hepatitis B (AHB) patients.
- TLR7 gene copy numbers were quantified using the AccuCopy method.
- Statistical analyses, including chi-squared tests, odds ratios, and confidence intervals, were employed to assess associations.
Main Results:
- A significant association was observed between low TLR7 copy number and increased susceptibility to chronic HBV infection in both male (OR=0.329) and female (OR=0.292) patients.
- No significant differences in TLR7 copy number were found among different stages of chronic HBV infection (CHB, liver cirrhosis, hepatocellular carcinoma).
- TLR7 copy number did not correlate with HBV e antigen titers.
Conclusions:
- Reduced copy number of the TLR7 gene represents a genetic risk factor for developing chronic HBV infection.
- TLR7 CNVs are not associated with the progression of liver disease in patients with chronic hepatitis B.
Aim:
To explore whether copy number variations (CNVs) of toll-like receptor 7 (TLR7) are associated with susceptibility to chronic hepatitis B virus (HBV) infection.
Methods:
This study included 623 patients (495 males and 128 females) with chronic hepatitis B virus infection (CHB) and 300 patients (135 females and 165 males) with acute hepatitis B virus infection (AHB) as controls. All CHB patients were further categorized according to disease progression after HBV infection (CHB, liver cirrhosis, or hepatocellular carcinoma). Copy numbers of the TLR7 gene were measured using the AccuCopy method. χ tests were used to evaluate the association between TLR7 CNVs and infection type. P values, odds ratios, and 95% confidence intervals (CIs) were used to estimate the effects of risk.
Results:
Among male patients, there were significant differences between the AHB group and CHB group in the distribution of TLR7 CNVs. Low copy number of TLR7 was significantly associated with chronic HBV infection (OR = 0.329, 95%CI: 0.229-0.473, P < 0.001). Difference in TLR7 copy number was also found between AHB and CHB female patients, with low copy number again associated with an increased risk of chronic HBV infection (OR = 0.292, 95%CI: 0.173-0.492, P < 0.001). However, there were no significant differences in TLR7 copy number among the three types of chronic HBV infection (CHB, liver cirrhosis, or hepatocellular carcinoma). In addition, there was no association between TLR7 copy number and titer of the HBV e antigen.
Conclusion:
Low TLR7 copy number is a risk factor for chronic HBV infection but is not associated with later stages of disease progression.
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02:26Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
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