Association between CTLA-4 exon-1 +49A& gt; G polymorphism and primary biliary cirrhosis risk: a meta-analysis. Arch Med Res. 2011;42:235-238. [PMID: 21722820 DOI: 10.1016/j.arcmed.2011.04.004]

Genetic Polymorphisms of Cytotoxic T-Lymphocyte Antigen 4 in Primary Biliary Cholangitis: A Meta-Analysis

Background and Aim

The connection between gene polymorphisms of cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and primary biliary cholangitis (PBC) is still vague and blurred. The purpose of this study is to precisely estimate the association of the polymorphisms of CTLA4 with the risk of PBC by using a meta-analysis.

Methods

PubMed and the Chinese National Knowledge Infrastructure (CNKI) database were used to search correlative literatures, and the documents which were about the relationships between the polymorphisms of CTLA4 (rs231775, rs231725, rs3087243, and rs5742909) and PBC were collected as of June 2016. The strength of correlation based on odds ratios (ORs) and its 95% confidence intervals (95%CIs) was computed by STATA.

Results

Generally, in rs231775, a significant risk was found in G allele, the value of OR was 1.32, and its 95%CI was 1.19 to 1.47. The same situation was found in A allele of rs231725, the value of OR was 1.33, and its 95%CI was 1.22 to 1.45. As genotypic level, different genotypic models were also found to have obvious relevance with PBC in rs231775 and rs231725. No obvious connections were found in other SNPs.

Conclusion

This study indicated that the polymorphisms of rs231775 and rs231725 would be the risk factors of PBC.

Association between cytotoxic T-lymphocyte antigen 4 gene polymorphisms and primary biliary cirrhosis in Chinese population: data from a multicenter study

BACKGROUND AND AIMS

The cytotoxic T-lymphocyte antigen 4 (CTLA4) gene polymorphisms have been shown to be associated with the risk of primary biliary cirrhosis (PBC). The study aimed to confirm the associations of CTLA4 gene polymorphisms with risk of PBC and patients' quality of life in Chinese population.

METHODS

A total of 312 female PBC patients from Chinese Han population were included as case, and 375 age-matched female healthy volunteers were included as control. Four single nucleotide polymorphisms (SNPs) including rs231775, rs3087243, rs231725, and rs5742909 were genotyped. The differences of genotype and allele distributions between PBC patients and healthy controls were assessed. The relationship between CTLA4 gene polymorphisms and healthy status of PBC patients were then investigated through comparisons of the domain scores of PBC-40 questionnaire between different genotype categories of each single nucleotide polymorphism.

RESULTS

The frequencies of G allele at rs231775 and A allele at rs231725 were both significantly increased in PBC patients when compared with normal controls (P < 0.001, odds ratio = 1.44, 95% confidence interval = 1.24-1.67 for rs231775; P < 0.001, odds ratio = 1.29, 95% confidence interval = 1.12-1.48 for rs231725). Besides, patients carrying A allele of rs3087243 had significantly lower score of fatigue domain than those carrying G allele (2.5 ± 0.8 vs 3.9 ± 1.3, P < 0.001).

CONCLUSIONS

This study revealed that CTLA4 gene polymorphism might be associated with susceptibility of PBC. G allele of rs231775 and A allele of rs231725 were significantly associated with the risk of PBC. In addition, patients carrying A allele of rs3087243 could have significantly better quality of life than those carrying G allele.

The role of vitamin d in primary biliary cirrhosis: possible genetic and cell signaling mechanisms

Primary biliary cirrhosis (PBC) is an immune-mediated chronic inflammatory disease of the liver of unknown etiology. Vitamin D deficiency is highly prevalent in patients with PBC, and many studies have demonstrated the significant effect of calcitriol on liver cell physiology. Vitamin D has antiproliferative and antifibrotic effects on liver fibrosis. Genetic studies have provided an opportunity to determine which proteins link vitamin D to PBC pathology (e.g., the major histocompatibility complex class II molecules, the vitamin D receptor, toll-like receptors, apolipoprotein E, Nramp1, and cytotoxic T lymphocyte antigen-4). Vitamin D also exerts its effect on PBC through cell signaling mechanisms, that is, matrix metalloproteinases, prostaglandins, reactive oxygen species, and the transforming growth factor betas. In conclusion, vitamin D may have a beneficial role in the treatment of PBC. The best form of vitamin D for use in the PBC is calcitriol because it is the active form of vitamin D3 metabolite, and its receptors are present in the sinusoidal endothelial cells, Kupffer cells, and stellate cells of normal livers, as well as in the biliary cell line.

Transforming growth factor-β genetic polymorphisms on development of liver cirrhosis in a meta-analysis

Transforming growth factor-β (TGF-β) protein has been supposed to be a risk factor for liver cirrhosis; however, the associations between its genes (TGF-β -509C>T and +869T>C) and liver cirrhosis remained unclear. This study was to quantitatively analyze the correlations by using a meta-analysis. Pubmed, Embase, Wanfang databases were retrieved up to November 1st, 2011. Odds ratio (OR) and 95 % confidence interval (95 %CI) were used to demonstrate the strength of association, and P < 0.05 of Z test indicated statistical significance. Combined analyses were performed by using fixed or random-effect model, depending on between-study heterogeneity. Seven studies were for TGF-β -509C>T polymorphism, and eight studies were for +869T>C polymorphism. Combined results indicated that neither TGF-β -509C>T nor +869T>C polymorphisms were associated with risk of liver cirrhosis [OR (95 % CI): 0.79 (0.60-1.04) for CT vs. TT of -509C>T and 0.87 (0.68-1.12) for CT vs. CC of +869T>C], with no between-study heterogeneity. In addition, subgroups analyses still inferred that two polymorphisms were not associated with risk of liver cirrhosis for HBV-infected patients, Asians and for Population-based studies. This meta-analysis indicated that neither TGF-β -509C>T nor +869T>C polymorphisms were associated with risk of liver cirrhosis, regardless of HBV infection or not.

Recent advances in understanding the pathogenesis of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic autoimmune liver disease characterized by the destruction of small intrahepatic bile ducts and the presence of highly specific serum antimitochondrial antibodies (AMAs). The human leukocyte antigen (HLA) gene has been proved to have strongest association with PBC susceptibility, and non-HLA genes, including IL12A, IL12RB2, STAT4, IRF5-TNPO3, ORMDL3/IKZF3, MMEL1, SPIB, CTLA-4, FCRL3 and A2BP1, are also closely associated with PBC susceptibility. Four AMAs including anti-M2, anti-M4, anti-M8 and anti-M9, and antinuclear antibodies (ANAs), such as antinuclear dot antibodies (SP100, PML, NDP52, SP140), antinuclear pore antibodies (gp210, p62), antinuclear envelope antibodies (Lamin and Lamin B receptor), and anti-centromere antibodies, may also be involved in the pathogenesis of PBC. The imbalance between Th17 cells and regulatory T lymphocytes (Treg) may also play an important role in the pathogenesis of PBC. In addition, senescence, autophagy, apoptosis of biliary epithelial cells (BECs), and environmental factors, such as Epstein-Barr virus (EBV) infection and smoking, may also contribute to the pathogenesis of PBC. Understanding of the mechanisms responsible for the pathogenesis of PBC has important implications for the treatment of PBC.

Cytotoxic T-lymphocyte associated antigen-4 gene polymorphisms and primary biliary cirrhosis: a systematic review

BACKGROUND AND AIM

The cytotoxic T-lymphocyte antigen 4 (CTLA4) is an inhibitory receptor expressed on activated and regulatory T lymphocytes. Polymorphisms could have remarkable effects on susceptibility to autoimmunity. However, the associations between CTLA-4 polymorphisms and primary biliary cirrhosis (PBC) remain ambiguous. The aim of this meta-analysis is to determine more precise estimations of the relationship.

METHODS

From literature retrieval from PubMed, Web of Science, Science Direct, and the Chinese National Knowledge Infrastructure (CNKI) Database, the publications on the associations between rs231775, rs3087243, rs5742909, rs231725 and rs11571317 polymorphisms of CTLA4 and PBC through June 2011 were collected. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated in fixed or random model, I(2) was calculated to examine heterogeneity, and funnel plots were plotted to examine small study effects with Revman 5.1 and Stata 11.

RESULTS

Overall, a significantly increased risk was found for G versus A allele for rs231775 (OR = 1.28, 95% CI = 1.17-1.41). For rs3087243, a significant association was found for AA versus GG genotype (OR = 0.66; 95% CI = 0.55-0.80). When subgroup analysis by ethnicity was performed, the same association was only found in Caucasians. For rs231725, the OR values (95% CI) for GG versus AA, GA versus AA and G versus A allele were 0.52 (0.40-0.68), 0.74 (0.60-0.92) and 0.73 (0.61-0.88). No significant associations were found for other polymorphisms.

CONCLUSION

The G allele of rs231775 is a risk factor for PBC, while AA genotype of rs3087243 and GG, GA and G allele of rs231725 show negative associations with PBC.