The influence of the human genome on chronic viral hepatitis outcome

Gestational Weight Gain: Is the Role of Genetic Variants a Determinant? A Review

Excessive or insufficient gestational weight gain (GWG) leads to diverse adverse maternal and neonatal outcomes. There is evidence that pregestational body mass index (pBMI) plays a role in GWG, but no genetic cause has been identified. In this review, we aim to analyze genotype variants associated with GWG. Results: We identified seven genotype variants that may be involved in GWG regulation that were analyzed in studies carried out in Brazil, Romania, the USA, Turkey, Ukraine, and Canada. Some genetic variants were only associated with GWG in certain races or depending on the pBMI. In women who were obese or overweight before gestation, some genetic variants were associated with GWG. Environmental and genetic factors together showed a greater association with GWG than genetic factors alone; for example, type of diet was observed to have a significant influence. Conclusions: We found little scientific evidence of an association between genotype variants in countries with a high prevalence of women of reproductive age who are overweight and obese, such as in Latin America. GWG may be more dependent on environmental factors than genetic variants. We suggest a deeper study of genetic variants, cytokines, and their possible association with GWG, always with the respective control of potential cofounding factors, such as pBMI, diet, and race.

Association of deleted in liver cancer-1 gene polymorphism with increased risk of chronicity of disease among Malaysian patients with hepatitis B infection

OBJECTIVE

The aim of this study is to examine the association between genetic variations in deleted in liver cancer 1 (DLC1) gene with progression of the hepatitis B virus (HBV) infection.

METHODS

A total of 623 subjects were included in this study, of whom, 423 were chronic hepatitis B (CHB) patients without liver cirrhosis or hepatocellular carcinoma (HCC), 103 CHB with either liver cirrhosis ± HCC and 97 individuals who had resolved HBV. Two single-nucleotide polymorphisms rs3739298 and rs532841 of DLC1 gene were genotyped using the Sequenom MassARRAY platform.

RESULTS

Our results indicated significant differences between the chronic HBV and resolved HBV groups in genotype and allele frequencies of DLC1-rs3739298 [odds ratio (OR) = 2.23; 95% confidence interval (CI): 1.24-3.99; P = 0.007] and (OR = 1.54; 95% CI: 1.07-2.22; P = 0.021), respectively. Moreover, haplotype analysis revealed significant associations between chronicity of HBV with TG and GA haplotypes (P = 0.041 and P = 0.042), respectively.

CONCLUSION

A significant association exists between the rs3739298 variant and susceptibility to CHB infection.

Relationship between HLA-DRB1 gene polymorphism and breast cancer: A protocol for systematic review and meta-analysis

BACKGROUND

Breast cancer is one of the common malignant tumors in women, which seriously affects women's physical and mental health and even life-threatening. The occurrence and development of breast cancer are closely related to genetic factors. Many studies have shown that human leukocyte antigen DRB1 is associated with the development of breast cancer, but lack evidence. This study aims to systematically evaluate the relationship between HLA-DRB1 gene polymorphism and breast cancer.

METHODS

The retrieval time of this study was from the establishment of the database to February 2021. The retrieval databases included CNKI, Wanfang, VIP and China Biomedical Database, PubMed, Embase, Web of Science, and the Cochrane Library. The retrieval objects were observational studies on the relationship between HLA-DRB1 gene polymorphism and breast cancer (including case--control studies, cross-sectional studies, and cohort studies). The language restrictions were English and Chinese. Two researchers independently extracted the data and assessed the quality of the included studies, and Stata 16.0 software was used for statistical analysis.

RESULTS

This study will systematically evaluate the relationship between HLA-DRB1 gene polymorphism and breast cancer based on existing studies.

CONCLUSION

This study will explore the early warning signal of breast cancer genetic susceptibility, and provide evidence-based medical evidence for clarifying the role of HLA-DRB1 gene polymorphism in breast cancer.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/847FQ.

HLA-G gene 14-bp deletion variant protects Iranian subjects against chronic hepatitis B infection

To investigate whether 14-bp Ins/Del polymorphism in HLA-G gene is associated with the risk of chronic hepatitis B (CHB) infection. This study was performed on a total of 396 individuals including 199 CHB patients and 197 healthy subjects from a south-east Iranian population. We genotyped 14-bp Ins/Del polymorphism in the HLA-G gene using polymerase chain reaction method. The results of our study revealed that the HLA-G 14-bp deletion polymorphism was associated with a reduced risk of CHB at both allele and genotypic levels. The 14-bp Del allele and Ins/Del genotype were more frequent in control group than in CHB patients (37% vs 28% for Del allele with OR = 0.68 and p-value = .015; 73% vs 52% for Ins/Del genotype with OR = 0.43 and p-value = .001) and both were protective factors against CHB. However, no difference was found in the distribution of HLA-G 14-bp genotypes among subjects with varied levels of HBV DNA or hepatic enzymes (p > .05). Our findings, for the first time, suggest that the HLA-G 14-bp Ins/Del polymorphism may be a marker for genetic susceptibility to CHB infection.

Lack of relationship between PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms and chronic hepatitis B virus infection

TP53 and phosphate and tension homolog (PTEN) are two tumor suppressor genes that regulate cell proliferation, migration, and death. P53 and PTEN deficiency has been associated with hepatic fibrosis, a prominent pathological feature associated with chronic hepatitis B (CHB). The present study is aimed to assess the association of PTEN 32-bp Ins/Del (rs34421660) and TP53 16-bp Ins/Del polymorphisms with CHB infection susceptibility. A total of 411 subjects were recruited in this case-control study of 213 patients with CHB infection and 198 healthy individuals as controls. PTEN and TP53 deletions were detected by polymerase chain reaction method. We found no significant association between PTEN 32-bp Ins/Del polymorphism and the risk for CHB using either of codominant (Ins/Del vs. Ins/Ins: P = 0.427; Del/Del vs. Ins/Ins: P = 0.235), dominant (Ins/Del + Del/Del vs. Ins/Ins P = 0.343) or recessive genetic model (Del/Del vs. Ins/Ins + Ins/Del: P = 0.516). At allelic level although the PTEN Del variant allele was more common in CHB patients compared to controls (55 vs. 51), but the difference did not reach the statistical significant range (OR 0.87, P = 0.327). Similarly, no association was observed between TP53 16-bp Ins/Del and the risk for CHB infection at both genotype and allele levels (P > 0.05). In summary, our study demonstrated that the PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms did not affect the risk of CHB infection in the Iranian population.

Association between TGFβ1 polymorphisms and chronic hepatitis B infection in an Iranian population

INTRODUCTION:

Transforming growth factor-beta 1 (TGFβ1) is a potent suppressive cytokine that contributes to chronic hepatitis B (CHB) infection. Disparities in TGFβ1 production among individuals have been attributed to TGFβ1 genetic polymorphisms. We examined whether three putative polymorphisms in TGFβ1[-509 C/T (rs1800469), +869 C/T (rs1800470), and +11929 C/T (rs1800472)]are associated with CHB infection in a South-Eastern Iranian population.

METHODS:

In total, 341 subjects were recruited, including 178 patients with CHB and 163 healthy individuals as controls. Genotyping of the three TGFβ1 SNPs was performed by tetra amplification refractory mutation system-PCR.

RESULTS:

TheTGFβ1 +869 TT vs.CC genotype in codominant (OR=0.445, p=0.012) and TT vs. TC+CC in the recessive (OR=0.439, p=0.003) model as well as the variant allele T vs. C(OR=0.714, p=0.038) were associated with lower CHB infection risk. However, the +11929 C/T polymorphism was associated with increased CHB risk, and the CT vs. CC genotype (OR=2.77, P=0.001) and T variant allele (OR=2.53, P=0.002) were risk factors for CHB. Furthermore, TTT (+869/-509/+11929) and CCC haplotypes were risk and protective factors for CHB, respectively. We found no significant association between viral DNA load and TGFβ1 genotype or hepatic enzyme levels (p >0.05).

CONCLUSIONS:

Results indicated that the TGFβ1+869TT genotype and T allele were protective factors, whereas the +11929 CT genotype and T allele were risk factors for CHB infection.

Human Platelet Polymorphism can be a genetic marker associated with HIV/HCV coinfection

To evaluate the associations of HPA polymorphisms -1, -3, and -5 with HIV/HCV coinfection were included in this study 60 HIV/HCV-coinfected patients from the Sao Paulo State health service centers. Data reported by Verdichio-Moraes et al. (2009: J. Med Virol 81:757-759) were used as the non-infected and HCV monoinfected groups. Human Platelet Polymorphism genotyping was performed in 60 Patients co-infected with HIV/HCV by PCR-SSP or PCR-RFLP. HIV subtyping and HCV genotyping was performed by RT-PCR followed sequencing. The data analyses were performed using the χ2 test or Fisher's Exact Test and the logistic regression model. Patients coinfected with HIV/HCV presented HCV either genotype 1 (78.3%) or non-1 (21.7%) and HIV either subtype B (85.0%) or non-B (15%). The Human Platelet Polymorphism-1a/1b genotype was more frequent (P < 0.05) in HIV/HCV coinfection than in HCV monoinfection and the allelic frequency of Human Platelet Polymorphism-5b in the Patients coinfected with HIV/HCV was higher (P < 0.05) than in HCV monoinfected cases and non-infected individuals. These data suggest that the presence of specific HPA allele on platelets could favor the existence of coinfection. On the other hand, Human Platelet Polymorphism-5a/5b was more frequent (P < 0.05) in HIV/HCV coinfected and HCV monoinfected groups than in the non-infected individuals, suggesting that this platelet genotype is related to HCV infection, regardless of HIV presence. Results suggest that the Human Platelet Polymorphism profile in HIV/HCV coinfected individuals differs from the one of both HCV monoinfected and non-infected population. So, the Human Platelet Polymorphism can be a genetic marker associated with HIV/HCV coinfection.

Association between TGFB1 915G/C polymorphism and susceptibility to chronic hepatitis C virus infection: A meta-analysis

The human transforming growth factor-β1 (TGF-β1) gene, namely TGFB1, contains several single-nucleotide polymorphisms (SNPs) and some of the polymorphic variants were shown to affect the TGF-β1 protein levels. A number of studies reported the association between 915G/C polymorphism and susceptibility to chronic hepatitis C virus (HCV) infection. However, the results were inconsistent. This meta-analysis was conducted to assess the association of TGFB1 915G/C polymorphism with susceptibility to chronic HCV infection. PubMed, ISI Web of Knowledge, ScienceDirect and Google Scholar databases were systematically searched up to August, 2013 to identify relevant studies. The pooled odds ratios (ORs) with their corresponding 95% confidence intervals (95% CIs) were calculated in 5 genetic comparison models (C vs. G, CC vs. GG, GC vs. GG, CC vs. GG+GC and CC+GC vs. GG). The Galbraith plot and subgroup analyses based on ethnicity, genotyping methods, sample size and fibrosis were performed to investigate possible sources of heterogeneity. A sensitivity analysis and assessment of publication bias were also conducted. Finally, 8 eligible case-control studies on TGFB1 915G/C polymorphism, including a total of 910 cases and 632 controls, were included in this meta-analysis. Overall, there was no evidence of any gene-disease association obtained from the subgroup analyses. Therefore, this meta-analysis demonstrated that there is no association between TGFB1 915G/C polymorphisms and susceptibility to chronic HCV infection.

IL28B and IL10R -1087 polymorphisms are protective for chronic genotype 1 HCV infection and predictors of response to interferon-based therapy in an East-Central European cohort

BACKGROUND

Previous studies have shown that single nucleotide polymorphisms (SNP) in IL28B and IL10R are associated with sustained virological response (SVR) in chronic hepatitis C patients treated with pegilated interferon plus ribavirin (P/R). The present study extends our earlier investigations on a large East-Central European cohort. The allele frequencies of IL28B and IL10R in genotype 1 HCV infection were compared with that of healthy controls for the purpose of examining the relationship between the polymorphisms and the SVR to P/R treatment.

METHODS

A total of 748 chronic HCV1 infected patients (365 male, 383 female; 18-82 years) and 105 voluntary blood donors as controls were enrolled. Four hundred and twenty HCV patients were treated with P/R for 24-72 weeks, out of them 195 (46.4%) achieved SVR. The IL28 rs12979860 SNP was determined using Custom Taqman SNP Genotyping Assays. The IL10R -1087 (also known as IL10R -1082 (rs1800896) promoter region SNP was determined by RT-PCR and restriction fragment length polymorphism analysis.

RESULTS

The IL28B CC genotype occurred with lower frequency in HCV patients than in controls (26.1% vs 51.4%, p<0.001). P/R treated patients with the IL28B CC genotype achieved higher SVR rate, as compared to patients with CT (58.6% vs 40.8%, p=0.002). The prevalence of IL10R -1087 GG genotype was lower in patients than in controls (31.8 % vs 52.2%, p<0.001). Among patients achieving SVR, the IL10R -1087 GG genotype occurred with higher frequency than the AA (32.0% vs 17.4%, p=0.013). The IL28B T allele plus IL10R A allele combination was found with higher prevalence in patients than in controls (52% vs 20.7%, p<0.001). The IL28B CC plus IL10R A allele combination occurred with higher frequency among patients with SVR than in non-responders (21.3% vs 12.8%, p=0.026). Both the IL28B CC plus IL10R GG and the IL28B CC plus IL10R A allele combinations occurred with lower frequency in patients than in controls.

CONCLUSIONS

In our HCV1 patients, both the IL28B CC and IL10R GG genotypes are associated with clearance of HCV. Moreover, distinct IL28B and IL10R allele combinations appear to be protective against chronic HCV1 infection and predictors of response to P/R therapy.

Association of Interleukin-1β and Gene Polymorphisms with Liver Pathogenesis in Hepatitis B Virus Infection among Eastern Indian Population

BACKGROUND

Interleukin-1β (IL-1β) is an important member of the family of the proinflammatory cytokines that modulate outcome of hepatitis B virus (HBV) infection.

OBJECTIVES

This study was designed to investigate the relationship between the polymorphic genotypes of the interleukin-1β (IL-1β) promoter region and the interleukin-1 receptor antagonist gene (IL-1RN) and disease outcome in HBV-infected individuals.

METHODS

DNA was extracted from 395 study subjects including HBV carriers with varying clinical presentations, as well as healthy controls and spontaneously recovered cases (SRC). Polymorphisms in IL-1β (at position -511) and IL-1RN (variable nucleotide tandem repeats, VNTR) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR based assay respectively.

RESULTS

Among the study subjects, different IL-1β (at position -511) (CC, CT and TT) and IL-1RN (1/1, 1/2, 2/2 and 1/3) polymorphic genotypes were found at variable proportions. Logistic regression analysis revealed, no notable difference at the level of IL-1β promoter (P = 0.244; OR = 0.78; 95% CI = 0.52-1.18) or IL-1RN genotype polymorphism (P = 0.840; OR = 1.03; 95% CI = 0.78-1.36) among the HBV carriers and controls or SRC cases. Pairwise proportion testing showed, IL-1β -511 genotype CC was significantly higher among asymptomatic carriers (ASC) in comparison with liver cirrhosis (LC) patients (P value = 0.028) and healthy control group (P-value = 0.036). IL-1RN genotype 2/2 was considerably higher in LC group than SRC as well as control group. Combinations of IL-1β (-511) and IL-1RN polymorphisms were associated with disease progression, such as CC-1/2 with ASC and TT-2/2 with LC.

CONCLUSION

IL-1β polymorphisms are found to be associated with disease severity. Different polymorphic combinations are associated with degree of disease severity. Overall this is the first report from Eastern India, which shows association of IL-1β polymorphisms with HBV-related hepatic complications.

Host genetic factors in hepatitis B infection, liver cancer and vaccination response: a review with a focus on Africa

The disease burden due to hepatitis B virus (HBV) infection remains significant; 350 million people are infected world-wide, and around half a million deaths each year are due to HBV-related liver disease and hepatocellular carcinoma (HCC). Infant immunisation against infection was introduced in the early 1980s, the vaccine is routinely administered across regions where the disease is endemic and has been shown to be safe and effective. However, the large number of older individuals with persistent infection means that disease will not be reduced significantly for several decades. Furthermore, failure to respond to the vaccination has been observed in about 5% of vaccinees and to date we have limited information on the durability of vaccine protection against infection. Hepatitis B infection and disease pathogenesis are known to be influenced by a number of factors including host genetics factors. This review aims to give an overview of the role of genetic variation in persistent HBV infection and the development of liver disease including HCC. Vaccine-induced immunity is, at least in part, heritable and we also discuss findings on the genetic control of responses to HBV vaccination. The epidemiology of HBV infection differs by world region, as does the genetic makeup of individuals originating from different regions. This review focuses on the situation in Africa, where hepatitis B is highly endemic.

The influence of HLA alleles and HBV subgenotyes on the outcomes of HBV infections in Northeast China

Hepatitis B virus (HBV) infection has a wide variety of clinical outcomes, it could be spontaneouly recovered and also could develop fulminant liver failure or cirrhosis with hepatocellular carcinoma. Human leukocyte antigen (HLA) polymorphism and HBV (sub)genotypes have been speculated to associate with the outcome of HBV infection because the data obtained from various populations who bear different HLA alleles have shown a HLA polymorphism associated outcome of HBV infection. However, as the most important viral and host genetic factors, the impact of HBV (sub)genotypes in combination with HLA polymorphism on the clinical outcomes of HBV infections remains unclear. To demonstrate the association of HLA allele polymorphism in combination with HBV subgenotypes with the outcome of HBV infection in Northeastern Han Chinese population, a total of 230 HBV-infected individuals (Infection group) were compared to 210 random selected controls (Control group) who are negative for HBV infection for their HLA alleles frequency as well as the associations with the virus infection, clearance and persistence in combination with HBV subgenotypes. Of the 230 HBV-infected subjects, 54 were acute self-limited hepatitis (ASH) with HBV subgenotype C2 (ASH-C2), 144 were chronic hepatitis (CH) with HBV subgenotype C2 and B2 (CH-C2 and CH-B2), and 32 were spontaneously recovered (SR) without subgenotype results. When two groups are compared, the results suggest that B*48, B*51 and DRB1*12 carrier may have a high risk for HBV infection, but B*51 is likely association with spontaneous recovery and DRB1*07, 12 may be implied in viral persistence. HLA-B*15, DRB1*11 and 14 associated with viral clearance in the cases of HBV-C2 infection; HLA-B*54 carriers in chronic group are more sensitive to with the infection of HBV subgenotype B2; HLA-B*07 and DRB1*13 may protect subjects from HBV infection. The data presented a link between HLA polymorphism and HBV pathogenesis and suggested potential therapeutic targets for hepatitis B.

Secreted protein acidic and rich in cysteine (SPARC) gene polymorphism association with hepatocellular carcinoma in Italian patients

BACKGROUND AND AIM

Hepatocellular carcinoma (HCC) is a multifactorial disease driven by both genetic and epigenetic factors. Infection, inflammation and the immune response against hepatitis B virus and hepatitis C virus have been shown to play an important role in increasing cancer risk and promoting tumor development. In order to investigate the genetic component influencing HCC development, we analyzed 50 single nucleotide polymorphisms (SNP) spanning 34 different genes in 230 Italian patients affected by HCC and 230 controls.

METHODS

Genes were selected on the basis of their known biological function and their possible involvement in the progression or in the susceptibility to HCC was considered. SNP genotyping was performed using allelic-specific fluorescent probes.

RESULTS

For most SNP, no differences were identified between HCC patients and controls, with the exception of rs2304052, localized on the secreted protein acidic and rich in cysteine (SPARC) gene, which was significantly associated to the disease. The C allele was significantly more frequent in the HCC patients than in the healthy controls (23% vs 10%, corrected P < 0.001), as well as the CC genotype (13% vs 1%, corrected P < 0.001).

CONCLUSION

Since the presence of the rs2304052 C allele is associated with an increased risk (odds ratio: 2.76) of developing hepatocarcinoma, our results allowed us to identify a SNP in the SPARC gene correlating to HCC susceptibility.

Influence of a single nucleotide polymorphism in the P1 promoter of the furin gene on transcription activity and hepatitis B virus infection

Hepatitis B e antigen (HBeAg) is a viral strategy of immune response evasion associated with hepatitis B virus (HBV) persistence. Spontaneous HBeAg seroconversion is usually accompanied by liver disease remission. Unfortunately, this goal is difficult to achieve and requires expensive and time-consuming treatment. Furin, a proprotein convertase, is involved in HBeAg maturation and is therefore a potential therapeutic target or indicator for predicting disease progression and antiviral response. Here we demonstrate that healthy Han Chinese from southern China (an endemic area of HBV infection) harbor a common single nucleotide polymorphism (SNP; -229 C/T) in a 1268-bp region of the P1 promoter of the furin gene [FES upstream region (Fur)]. A luciferase reporter gene assay showed that transcription activity is about 3 times higher in allele T carriers than in allele C carriers of this SNP. Allele T includes a suboptimal transcription factor NF-E2 [i.e., nuclear factor (erythroid-derived 2)]-binding motif according to bioinformatics and studies using site-directed mutagenesis. We also observed that individuals carrying allele T were more likely to become persistently infected. When persistently infected patients were divided into subgroups according to recent guidelines and HBeAg-defective virus infection was taken into account, patients with allele T or genotype TT had a decreased likelihood of HBeAg seroconversion or an increased likelihood of progressing to HBeAg-negative chronic hepatitis B or liver cirrhosis if accompanied by HBeAg-defective virus infection.

CONCLUSION

The common SNP in the P1 promoter of the Fur gene affects furin transcription activity and HBV infection outcome, possibly by increasing furin messenger RNA expression, and this suggests that furin is a potential therapeutic target and that this SNP is a potential predictor of disease progression or therapeutic response.

Genetic factors in mother-to-child transmission of HCV infection

HCV infection transmission rate in infants born to HCV-positive mothers is about 5%. HIV co-infection and high maternal RNA viral load are associated with increased transmission. The only genetic factor previously evaluated is HLA. We investigated the role of genetic factors already associated in adults with HCV infection evolution (HLA-DRB1, MBL2, TNF-alpha, IFN-gamma and IL-10), or liver disease progression (HFE and TGF-beta1). 384 Italian subjects were recruited, including 38 HCV-positive mother/child pairs; 104 infected, non-transmitting mothers with their 114 children; 21 vertically infected children and 69 HCV-exposed, uninfected children. Samples were analysed for previously described gene polymorphisms. Maternal HLA-DRB104 correlated with protection from vertical transmission (p=0.023), while HLA-DRB110 in children was a risk factor (p=0.036). Investigation of concordance degree in HLA-DRB1 locus revealed that a HLA mismatch between mother and child was a protective factor (p=0.017) indicating that alloreactive immune responses are involved in preventing HCV vertical transmission.

Polymorphisms and plasma soluble levels of E-selectin in patients with chronic hepatitis B virus infection

BACKGROUND

Infections with hepatitis B virus (HBV) may lead to a distinct clinical outcome which is partially related to host genetic variability. Our aim was to investigate the relationships between the polymorphisms of the E-selectin gene and disease progression in a HBV-infected Chinese Han population, and also to determine the plasma soluble E-selectin (sE-selectin) levels in this population.

METHODS

Genomic DNA was extracted from the peripheral blood of 367 HBV carriers and 281 healthy controls. Two polymorphisms (PstI for A561C and HphI for G98T) of the E-selectin gene were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Circulating sE-selectin levels were measured by specific enzyme-linked immunosorbent assay (ELISA).

RESULTS

The frequency of the C allele (AC or CC) of the A561C polymorphism was significantly higher in patients with liver cirrhosis (LC) compared to controls (p=0.002). There was no difference in allele distribution of the G98T polymorphism. But in patients with LC, classified according to the Child-Pugh classification, the frequency of the T carrier (GT and TT) was significantly different between Child-Pugh class A and class B plus C (p=0.009). Levels of plasma soluble E-selectin (sE-selectin) were significantly increased in HBV carriers with chronic hepatitis (CH) and LC (mean+/-SD 68.94+/-34.09 and 43.39+/-18.00 ng/mL) compared to controls (13.96+/-7.50 ng/mL) (p<0.01). In the LC subgroup, levels of sE-selectin were significantly decreased from Child-Pugh class A to class C (p<0.05). In each group, individuals with the C allele showed higher sE-selectin levels than those with the A allele (p<0.05).

CONCLUSIONS

This is the first report describing the association between E-selectin polymorphisms and HBV-related chronic liver diseases. Our data suggest that the A561C polymorphism of the E-selectin gene may be associated with disease progression in patients with chronic HBV infection and control the expression of plasma soluble levels, while the G98T polymorphism may be related to fibrotic severity in the Chinese population.

The association between the genetic polymorphism of HLA-DQA1, DQB1, and DRB1 and serum alanine aminotransferase levels in chronic hepatitis C in the Chinese population

BACKGROUND AND AIM

To investigate a possible association between HLA genes with serum alanine aminotransferase (ALT) levels and evaluate whether the HLA-DQA1, DQB1, and DRB1 genes could influence the development of liver damage in chronic hepatitis C.

METHODS

A total of 145 patients with chronic hepatitis C virus (HCV) infection (36 patients with persistently normal ALT values; 109 patients with elevated ALT levels) and 160 uninfected healthy controls were examined for HLA-DQA1, DQB1, and DRB1 molecules by using polymerase chain reaction-sequencing based typing (PCR-SBT).

RESULTS

Among the patients chronically infected with HCV, the frequencies of DQA1*0501, DQB1*0301, and DRB1*0401 alleles were significantly increased in the normal ALT group compared with those with abnormal ALT levels, whereas that of DQB1*0201 was significantly lower. As compared to uninfected healthy controls, DQA1*0501, DQB1*0301, and DRB1*0401 allele frequencies were also statistically higher in the normal ALT group, whereas that of DQB1*0201 was the inverse. The haplotype frequencies of DQA1*0301-DQB1*0301, DQA1*0501-DQB1*0301, and DRB1*1101-DQB1*0301 were found to be significantly higher in the normal ALT group. Multivariate logistic regression indicated that female sex, and the DQB1*0301 allele and DRB1*0401 allele were independently associated with normal ALT values, whereas DQB1*0201 allele was the inverse.

CONCLUSIONS

These results suggest that particular HLA alleles may have an influence on the serum ALT level of chronic HCV infection as a host genetic factor in the Chinese population. The DQA1*0501, DQB1*0301, and DRB1*0401 alleles, and the DQA1*0301-DQB1*0301, DQA1*0501-DQB1*0301, and DRB1*1101-DQB1*0301 haplotypes seem to be associated with low hepatitis activity; whereas DQB1*0201 allele is closely correlated with the progression of liver injury in chronic HCV infection.

Spontaneous and influenza virus-induced sleep are altered in TNF-alpha double-receptor deficient mice

Tumor necrosis factor-alpha (TNF-alpha) is associated with sleep regulation in health and disease. Previous studies assessed sleep in mice genetically deficient in the TNF-alpha 55-kDa receptor. In this study, spontaneous and influenza virus-induced sleep profiles were assessed in mice deficient in both the 55-kDa and 75-kDa TNF-alpha receptors [TNF-2R knockouts (KO)] and wild-type (WT) strain controls. Under baseline conditions the TNF-2R KO mice had less non-rapid eye movement sleep (NREMS) than WTs during the nighttime and more rapid eye movement sleep (REMS) than controls during the daytime. The differences between nighttime maximum and daytime minimum values of electroencephalogram (EEG) delta power during NREMS were greater in the TNF-2R KO mice than in WTs. Viral challenge (mouse-adapted influenza X-31) enhanced NREMS and decreased REMS in both strains roughly to the same extent. EEG delta power responses to viral challenge differed substantially between strains; the WT animals increased, whereas the TNF-2R KO mice decreased their EEG delta wave power during NREMS. There were no differences between strains in body temperatures or locomotor activity in uninfected mice or after viral challenge. Analyses of cortical mRNAs confirmed that the TNF-2R KO mice lacked both TNF-alpha receptors; these mice also had higher levels of orexin mRNA and reduced levels of the purine P2X7 receptor compared with WTs. Results reinforce the hypothesis that TNF-alpha is involved in physiological sleep regulation but plays a limited role in the acute-phase response induced by influenza virus.

Association between toll-like receptor polymorphisms and the outcome of liver transplantation for chronic hepatitis C virus

BACKGROUND

Experimental models suggest that immune cells recognize hepatitis C virus (HCV) through toll-like receptor (TLR)-2 and TLR4. We assessed the association between the single nucleotide polymorphism in genes that encode for these receptors and the outcome of liver transplantation for chronic HCV.

METHODS

A historical cohort of 92 liver transplant patients with chronic HCV were screened for TLR2 Arg753Gln and TLR4 Asp299Gly and Thr399Ile polymorphisms. The results were correlated with the predefined composite primary outcome of cirrhosis, retransplantation, and death. Statistical analysis was performed using Kaplan-Meier estimation and Cox proportional hazard model.

RESULTS

The mean patient age was 49+/-9 years. Sixty percent were male and 84% were white. Twelve (13%) patients had TLR2 Arg753Gln and 32 (35%) had TLR4 Asp299Gly and/or Thr399Ile polymorphism. During the mean follow-up period of 32 months after liver transplantation, the composite primary outcome occurred in 19 (24%) of 80 patients without TLR2 polymorphism, one (14%) of seven patients with heterozygous TLR2 polymorphism, and in all five (100%) patients with homozygous TLR2 polymorphism (P=0.0007). Time-to-event analysis showed a significant association between homozygous TLR2 polymorphism and the primary outcome (P<0.0001). After adjusting for donor age and azathioprine use, homozygous TLR2 mutation (RR 5.20 [1.65-13.9]; P=0.007) remained associated with the primary outcome. TLR4 polymorphisms were not associated with primary outcome.

CONCLUSION

Homozygous TLR2 Arg753Gln polymorphism is associated with allograft failure and mortality after liver transplantation for chronic HCV. The potential clinical relevance of this observation should encourage studies to assess its biologic mechanism.

Influence of IL-10RA and IL-22 polymorphisms on outcome of hepatitis C virus infection

BACKGROUND

Two receptor chains, IL-10RA and IL-10RB, are known to mediate the functions of interleukin-10 (IL-10), which has been shown to be involved in the progression of persistent hepatitis C virus (HCV) infection. Little information is available on the role of host genetic variation in IL-10 receptor genes and outcome of HCV infection. IL-22, an IL-10 homologue, shares the IL-10RB receptor chain with IL-10 and has antiviral properties. We investigated the possible role of polymorphisms in the IL-10RA and IL-22 genes in hepatitis C disease pathogenesis.

METHODS

This study population consisted of 631 HCV patients, recruited from several hepatology clinics across Europe. We genotyped four single-nucleotide polymorphisms (SNPs) in the IL-10RA and six SNPs in the IL-22 gene by ligation detection reaction or restriction fragment length polymorphism. Outcome of HCV infection was assessed according to viral clearance, treatment response, severity of fibrosis and overall inflammation.

CONCLUSIONS

Variation in IL-10RA appeared to be correlated with response to treatment and inflammation. Two SNPs in IL-22 affected treatment response and viral clearance respectively. We furthermore report on allele and haplotype frequencies and linkage disequilibrium for IL-10RA and IL-22. Our results indicate that genetic variation in these genes may play a modulatory role in the outcome of hepatitis C infection.

A promoter polymorphism in the interferon alpha-2 gene is associated with the clinical presentation of hepatitis B

Cytokine gene polymorphisms influence the severity of infectious diseases of viral and parasitic origin. Interferon alpha (IFN-alpha) is known to be involved in the defence against hepatitis B. The promoter of the IFN-alpha-2 gene was investigated for mutations in 344 hepatitis B virus (HBV)-infected Vietnamese patients and 293 uninfected Vietnamese. We found a deletion in the promoter, which was present significantly more frequently in HBV-infected patients than in control individuals; 20% of the healthy, whereas 35% of the HBV-infected cohort carries this deletion (P<0.001). Reporter gene assays showed that a construct with the deletion had a lower level of transcription in comparison to the wild type (P=0.011). These findings indicate that the deletion in the promoter of the IFN-alpha-2 gene reduces the transcription of this gene in vitro. This reduction could explain the individually different interferon levels in humans and could also be one cause of susceptibility to hepatitis B.

Genetic predisposition of responsiveness to therapy for chronic hepatitis C

Background: A combination of interferon-α (IFN-α) and ribavirin has been the choice for treating chronic hepatitis C (CHC) patients. It achieves an overall sustained response rate of approximately 50%; however, the treatment takes 6–12 months and often brings significant adverse reactions to some patients. It would therefore be beneficial to include a pretreatment evaluation in order to maximize the efficacy. In addition to viral genotypes, we hypothesize that patient genotypes might also be useful for the prediction of treatment response. Methods: We retrospectively analyzed the genetic differences of CHC patients that are associated with IFN/ribavirin responses. The DNA polymorphisms among 195 sustained responders and 122 nonresponders of CHC patients of Taiwanese origin were compared. Statistical and algorithmic methods were used to select the genes associated with drug response and single nucleotide polymorphisms (SNPs) that permitted the construction of a predictive model. Results: Association studies and haplotype reconstruction revealed selection of seven genes: adenosine deaminase, RNA-specific (ADAR), caspase 5, apoptosis-related cysteine peptidase (CASP5), fibroblast growth factor 1 (FGF1), interferon consensus sequence binding protein 1 (ICSBP1), interferon-induced protein 44 (IFI44), transporter 2, ATP-binding cassette, subfamily B (TAP2) and transforming growth factor, β receptor associated protein 1 (TGFBRAP1) for the responsiveness trait. Based on confirmed linkage disequilibrium block in the population, a minimal set of 26 SNPs in the seven selected genes was inferred. To predict treatment outcome, a multiple logistic regression model was constructed using susceptible genotypes of SNPs. The performance of the resultant model had a sensitivity of 68.2% and specificity of 60.7% on 317 CHC patients treated with IFN-combined therapy. In addition, a prediction model with both the host genetic and viral genotype information was also constructed which enhanced the performance with a sensitivity of 80.7% and specificity of 67.2%. Conclusions: A genetic model was constructed to predict outcomes of the combination therapy in CHC patients with high sensitivity and specificity. Results also provide a possible process of selecting targets for predicting treatment outcomes and the basis for developing pharmacogenetic tests.

Human leukocyte antigen class II DQB1*0301, DRB1*1101 alleles and spontaneous clearance of hepatitis C virus infection: a meta-analysis

AIM

To assess the associations of human leukocyte antigen (HLA) class II DQB1*0301 and/or DRB1*1101 allele with spontaneous hepatitis C virus (HCV) clearance by meta-analysis of individual dataset from all studies published till date.

METHODS

To clarify the impact of HLA class II polymorphisms on viral clearance, we performed a meta-analysis of the published data from 11 studies comparing the frequencies of DQB1*0301 and DRB1*1101 alleles in individuals with spontaneous resolution to those with persistent infection. As we identified the heterogeneity between studies, summary statistical data were calculated based on a random-effect model.

RESULTS

Meta-analyses yielded summary estimates-odds ratio (OR) of 2.36 [95%CI (1.62, 3.43), P<0.00001] and 2.02 [95%CI (1.56, 2.62), P<0.00001] for the effects of DQB1*0301 and DRB1*1101 alleles on spontaneous clearance of HCV, respectively.

CONCLUSION

These results support the hypothesis that specific HLA class II alleles might influence the susceptibility or resistance to persistent HCV infection. Both DQB1*0301 and DRB1*1101 are protective alleles and present HCV epitopes more effectively to CD4(+)T lymphocytes than others, and subjects with these two alleles are at a lower risk of developing chronic HCV infection. Large, multi-ethnic confirmatory and well-designed studies are needed to determine the host genetic determinants of HCV infection.

Association of polymorphisms of interleukin-18 gene promoter region with chronic hepatitis B in Chinese Han population

AIM: To investigate the polymorphisms of interleukin-18 (IL-18) gene promoters, and to disclose whether such polymorphisms are associated with susceptibility to chronic hepatitis B in Chinese Han population.

METHODS: Using polymerase chain reaction with sequence specific primers (PCR-SSP) method, the single nucleotide polymorphisms (SNPs) of the promoter region of IL-18 gene at position -607 and -137 were detected in 231 patients with chronic hepatitis B and 300 normal controls.

RESULTS: Allele C at position -607 in the promoter of IL-18 gene was detected in 48.7% of normal controls and 51.9% of patients, while allele A at position -607 was detected in 51.3% of normal controls and 48.1% of patients. The frequencies of -607CC, -607 CA and -607AA genotypes in normal controls were 22.0%, 53.3% and 24.7% respectively and in chronic hepatitis B patients were 26.8%, 50.2% and 23.0% respectively. Allele G at position -137 in the promoter of IL-18 gene was detected in 82.3% of normal controls and 88.5% of chronic hepatitis B patients, while allele C at position -137 was detected in 17.7% of normal controls and 11.5% of patients. The frequencies of -137GG, GC and CC genotype were 67.3%, 30.0% and 2.7% in normal controls respectively, while in chronic hepatitis B patients were 78.8%, 19.5% and 1.7% respectively. The frequency of -137GG genotype in chronic hepatitis B groups was significantly higher than that in normal controls (χ² = 8.55, P = 0.003 <0.05), whereas the frequencies of -607C/-137C and -607A/-137C haplotypes in chronic hepatitis B groups were significantly lower than that in normal controls. The association between genotypes of IL-18 promoter region polymorphisms and HBV copies showed that the frequency of -607AA genotype in high HBV-DNA copies groups was lower than that in low HBV-DNA copies groups (χ² = 6.03, P = 0.014 <0.05).

CONCLUSION: The polymorphisms of the promoter region of IL-18 gene at position -607 and -137 are closely associated with susceptibility to chronic hepatitis B. The people with allele C at position -137 in the promoter of IL-18 gene may be protected against HBV infection; moreover AA genotype at position -607 may be closely linked to inhibit HBV-DNA replication. These findings give some new clues to the study of pathogenesis of chronic hepatitis B.