Association of genetic variations in CCR5 and its ligand, RANTES with clearance of hepatitis B virus in Korea

G protein-coupled receptor (GPCR) pharmacogenomics

The field of pharmacogenetics, the investigation of the influence of one or more sequence variants on drug response phenotypes, is a special case of pharmacogenomics, a discipline that takes a genome-wide approach. Massively parallel, next generation sequencing (NGS), has allowed pharmacogenetics to be subsumed by pharmacogenomics with respect to the identification of variants associated with responders and non-responders, optimal drug response, and adverse drug reactions. A plethora of rare and common naturally-occurring GPCR variants must be considered in the context of signals from across the genome. Many fundamentals of pharmacogenetics were established for G protein-coupled receptor (GPCR) genes because they are primary targets for a large number of therapeutic drugs. Functional studies, demonstrating likely-pathogenic and pathogenic GPCR variants, have been integral to establishing models used for in silico analysis. Variants in GPCR genes include both coding and non-coding single nucleotide variants and insertion or deletions (indels) that affect cell surface expression (trafficking, dimerization, and desensitization/downregulation), ligand binding and G protein coupling, and variants that result in alternate splicing encoding isoforms/variable expression. As the breadth of data on the GPCR genome increases, we may expect an increase in the use of drug labels that note variants that significantly impact the clinical use of GPCR-targeting agents. We discuss the implications of GPCR pharmacogenomic data derived from the genomes available from individuals who have been well-phenotyped for receptor structure and function and receptor-ligand interactions, and the potential benefits to patients of optimized drug selection. Examples discussed include the renin-angiotensin system in SARS-CoV-2 (COVID-19) infection, the probable role of chemokine receptors in the cytokine storm, and potential protease activating receptor (PAR) interventions. Resources dedicated to GPCRs, including publicly available computational tools, are also discussed.

Do CCR5 (CCR5Δ32) and TLR3 (RS5743313) gene polymorphisms prevent chronic hepatitis B infection?

Hepatitis B virus (HBV) is still a significant health problem in human. HBV severity or sensitivity of patients may be based on the individual genetic factors significantly. The aim of this study is to investigate the association of CCR5 (CCR5Δ32), TLR3 (rs5743313) functional gene polymorphisms, interferon-gamma (IFN-ɣ) level in HBV infection, which are thought to play an important role in innate and acquired immunity in patients who have undergone HBV seroconversion and those who have chronic hepatitis B disease and receive treatment. One hundred patients who are became naturally immune against HBV infection (HBsAg negative, anti-HBc IgG, and anti-HBs IgG positive), and 100 patients with chronic hepatitis B infection (>6 months HBsAg positive) who are receiving oral antiviral therapy were compared for CCR5Δ32, TLR3 (rs5743313) genotypes and serum IFN-ɣ level. It was found that CCR5Δ32 polymorphism (Wt/Δ32 and Δ32/Δ32) was significantly higher in the chronic hepatitis B group (p = 0.048) but not for TLR3 gene polymorphism. However, serum IFN-ɣ level was significantly higher in the HBV seroconversion group (75 ± 89 ng/ml) than in the chronic hepatitis B group (4.35 ± 17.27 ng/ml) (p < 0.001). In conclusion, a higher CCR5Δ32 allele frequency in patients with chronic hepatitis B might be considered as a marker of progression to chronic hepatitis.

Beyond HIV infection: Neglected and varied impacts of CCR5 and CCR5Δ32 on viral diseases

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CCR5 regulates multiple cell types (e.g., T regulatory and Natural Killer cells) and immune responses.

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The effects of CCR5, CCR5Δ32 (variant associated with reduced CCR5 expression) and CCR5 antagonists vary between infections.

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CCR5 affects the pathogenesis of flaviviruses, especially in the brain.

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The genetic variant CCR5Δ32 increases the risk of symptomatic West Nile virus infection.

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The triad “CCR5, extracellular vesicles and infections” is an emerging topic.

The interactions between chemokine receptors and their ligands may affect susceptibility to infectious diseases as well as their clinical manifestations. These interactions mediate both the traffic of inflammatory cells and virus-associated immune responses. In the context of viral infections, the human C-C chemokine receptor type 5 (CCR5) receives great attention from the scientific community due to its role as an HIV-1 co-receptor. The genetic variant CCR5Δ32 (32 base-pair deletion in CCR5 gene) impairs CCR5 expression on the cell surface and is associated with protection against HIV infection in homozygous individuals. Also, the genetic variant CCR5Δ32 modifies the CCR5-mediated inflammatory responses in various conditions, such as inflammatory and infectious diseases. CCR5 antagonists mimic, at least in part, the natural effects of the CCR5Δ32 in humans, which explains the growing interest in the potential benefits of using CCR5 modulators for the treatment of different diseases. Nevertheless, beyond HIV infection, understanding the effects of the CCR5Δ32 variant in multiple viral infections is essential to shed light on the potential effects of the CCR5 modulators from a broader perspective. In this context, this review discusses the involvement of CCR5 and the effects of the CCR5Δ32 in human infections caused by the following pathogens: West Nile virus, Influenza virus, Human papillomavirus, Hepatitis B virus, Hepatitis C virus, Poliovirus, Dengue virus, Human cytomegalovirus, Crimean-Congo hemorrhagic fever virus, Enterovirus, Japanese encephalitis virus, and Hantavirus. Subsequently, this review addresses the impacts of CCR5 gene editing and CCR5 modulation on health and viral diseases. Also, this article connects recent findings regarding extracellular vesicles (e.g., exosomes), viruses, and CCR5. Neglected and emerging topics in “CCR5 research” are briefly described, with focus on Rocio virus, Zika virus, Epstein-Barr virus, and Rhinovirus. Finally, the potential influence of CCR5 on the immune responses to coronaviruses is discussed.

Role of the genetic variant CCR5Δ32 in HBV infection and HBV/HIV co-infection

CCR5 is a chemokine receptor that mediates the action of inflammatory cells, besides acting as an HIV co-receptor. CCR5Δ32 states for a genetic variant containing a 32 base pair deletion in the coding region of the CCR5 gene. In homozygosis, CCR5Δ32 results in the lack of CCR5 expression on the cell surface, which was associated with protection against HIV infection. Heterozygous individuals for CCR5Δ32 have a reduced CCR5 expression. Recent evidence demonstrates that CCR5 and CCR5Δ32 are involved in the pathogenesis of other viral infections besides HIV infection. Nevertheless, the role of CCR5 and CCR5Δ32 in HBV infection is not clear and conflicting results have been reported. Thus, the objective of this study was to investigate the role of CCR5Δ32 in HBV mono-infection and HBV/HIV co-infection in a population from southern Brazil. A total of 1113 individuals were evaluated, divided in controls (n = 334), HBV+ (n = 335), HBV+/HIV+ (n = 144), and including an HIV+ group to complement the analyses (n = 300, obtained from a previous study of our research team). The CCR5Δ32 allele frequencies found were 7.5 %, 9.0 %, and 3.1 %, respectively for controls, HBV+, and HBV+/HIV+ patients. The individuals were classified in CCR5Δ32 allele carriers and CCR5Δ32 allele non-carriers and the groups were compared using binary logistic regression adjusted for covariates. No significant effect of the CCR5Δ32 variant was observed on the susceptibility or protection against HBV mono-infection in individuals from southern Brazil. A potential protective effect of CCR5Δ32 on HBV/HIV co-infection was observed. However, it can be due to the effect of CCR5Δ32 in the protection against HIV infection or external factors not covered in the study. Finally, this study contributes to the understanding of the role of CCR5 in HBV infection, suggesting no effect of CCR5Δ32 on susceptibility to HBV mono-infection.

CCR5, MCP-1 and VDR Gene Polymorphisms Are Associated with the Susceptibility to HBV Infection

Genetic variants of chemokine and regulatory cytokines play functional roles in chronic HBV infection. The objective of the study, was to evaluate the association between the CCR5D32, CCR5-2459A/G, MCP-1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C SNPs and HBV susceptibility, in samples of Iranian populations. The CCR5D32, CCR5-2459A/G, MCP1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C polymorphisms were analyzed by polymerase chain reaction and PCR-RFLP using 100 chronic HBV infected (HBV) patients, 40 spontaneously recovered HBV (SR) subjects and 100 healthy controls (C). Also, serum levels of protein were monitored. The study showed that the existence of CCR5-2459A, MCP1-2518G and VDR-CC alleles significantly increased risk of chronic HBV infection. In addition, WtAGCC haplotype had a higher frequency in HBV patients than C and SR groups and might relate to the natural history of the infection. Statistical analysis indicated positive correlations between CCR5-2459A/G, MCP1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C genotypes and serum levels of the CCR5, MCP-1 and VDR in HBV patients. According to the statistical analysis, significant associations with susceptibility to chronic HBV infection was observed with CCR5-2459A/G, MCP1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C polymorphisms. In addition, no association of the CCR5D32 SNP with the disease was found.

Correlations between polymorphisms in the uridine diphosphate-glucuronosyltransferase 1A and C-C motif chemokine receptor 5 genes and infection with the hepatitis B virus in three ethnic groups in China

Objective

To determine whether genetic polymorphisms in the uridine diphosphate-glucuronosyltransferase 1A (UGT1A) and the C-C motif chemokine receptor 5 (CCR5) genes are associated with hepatitis B virus (HBV) infection in Yi, Yao and Han ethnic groups in the Guizhou Province of China.

Methods

The study enrolled subjects with and without HBV infection. Whole blood was used for DNA genotyping using standard techniques. The study determined the frequencies of several polymorphic alleles (UGT1A6 [rs2070959], UGT1A1 [rs8175347], CCR5-59029 [rs1799987] and CCR5Δ32 [rs333]) and then characterized their relationship with HBV infection.

Results

A total of 404 subjects were enrolled in the study: 138 from the Yao group, 101 from the Yi group and 165 from the Han group. There was a significant difference in the frequency of UGT1A1 rs8175347 polymorphisms among the three groups. The rates of 7TA carriers of UGT1A1 rs8175347 in all three groups were significantly higher than the other genotypes. Individuals with genotype AA of UGT1A6 rs2070959 in the Yi group had a higher risk for HBV infection than in the Yao and Han groups. The frequency of genotype GG in CCR5-59029 in the Yao group was significantly higher than in the Yi group. The genotypes of CCR5Δ32 were not associated with HBV infection.

Conclusion

These findings provide genetic and epidemiological evidence for an association of UGT1A and CCR5-59029 polymorphisms with HBV infection in Chinese Yi and Yao populations.

Possible Impact of 190G > A CCR2 and Δ32 CCR5 Mutations on Decrease of the HBV Vaccine Immunogenicity-A Preliminary Report

Background: Chemokine genetic variations are involved in infectious diseases such as hepatitis B virus (HBV). Several allelic variants might, in theory, affect the outcome of vaccination. Objectives: This study was carried out to examine the associations of Δ32 CCR5 and 190G > A CCR2 polymorphisms with a response to a primary course of three HBV vaccinations. Methods: Between December 2014 and December 2016, patients from three randomly selected primary care clinics in the West Pomeranian region (Poland), 1 month after receiving the third dose of HBV vaccine, were enrolled. Enzyme-linked immunosorbent assay (ELISA) system version 3.0 was used to detect anti-HBs and anti-HBc totals. The identification of polymorphisms were performed by a polymerase chain reaction technique using a single primer extension assay. Genotype distributions of responders versus non-responders to HBV vaccination were compared on the basis of anti-HBs level. Results: In 149 patients (mean age 60 years) the mean anti-HBs level was 652.2 ± 425.9 mIU/mL (range: 0–1111.0 mIU/mL). There were 14.1% (n = 21) non-responders to the HBV vaccine (anti-HBs < 10.0 mIU/mL). The wild type/Δ32 genotype of CCR5 gene was found in 18.1% participants, and 1.3% were Δ32/Δ32 homozygotes. The frequency of allele A of the CCR2 gene was 11.1%. Lower anti-HBs levels in Δ32/Δ32 homozygotes were observed (Me = 61 mIU/mL vs. Me = 660.2 mIU/mL; p = 0.048). As age was found to be a correlate to the anti-HBs titer (r = −0.218, p = 0.0075; 95% CI: −0.366–−0.059)—an analysis of a co-variance was performed which found a statistically significant (p = 0.04) difference in anti-HBs titres between Δ32/Δ32 homozygotes and other CCR5 genotypes. The association between anti-HBs titres and CCR2 genotypes was not statistically significant. Conclusions: Our study—which is a preliminary report that suggest this topic deserves further observation with larger sample sizes, different ethnicities, and other single nucleotide poly-morphisms (SNPs)—suggests the possible involvement of CCR5 polymorphism in impairing the immunologic response to HBV vaccination, predominantly in relation to the passage of time.

CCR5 Polymorphism as a Protective Factor for Hepatocellular Carcinoma in Hepatitis B Virus-Infected Iranian Patients

The CC chemokine receptor 5 (CCR5) delta 32 allele results in a nonfunctional form of the chemokine receptor and has been implicated in a variety of immune-mediated diseases. CCR5Δ32 may also predispose one to chronic liver disease or be linked with resistance to HBV infection. This study was undertaken to investigate any association between CCR5 polymorphism with resistance to hepatitis B or susceptibility to HBV infection. A total of 812 Iranian individuals were enrolled into two groups: HBV infected cases (n=357), who were HBsAg-positive, and healthy controls (n=455). We assessed polymorphisms in the CCR5 gene using specific CCR5 oligonucleotide primers surrounding the breakpoint deletion. Genotype distributions of the HBV infected cases and healthy controls were determined and compared. The CCR5/CCR5 (WW) and CCR5/CCR5Δ32 (W/D) genotypes were found in (98%) and (2%) of HBV infected cases, respectively. The CCR5 Δ32/Δ32genotype was not found in HBV infected cases. Genotype distributions of CCR5 in healthy controls were W/W genotype in (87.3%), W/D genotype in (11.2%) and D/D genotype in (1.5%). Heterozygosity for CCR5/CCR5Δ32 (W/D) in healthy controls was greater than in HBV infected cases (11.2% vs 2%, p < 0.001). W/D and D/D genotypes were more prominent in healthy controls than in HBV infected cases. This study provides evidence that the CCR5Δ32 polymorphism may have a protective effect in resistance to HBV infection at least in the Iranian population.

Human genes involved in hepatitis B virus infection

Persistent hepatitis B virus (HBV) infection is a significant public health problem because it is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC). Roughly one-third of the world population has been infected with HBV and there are about 350 million (5%-6%) persistent carriers. HBV causes 80% of all liver cancer cases and is the second most important carcinogen, after smoking tobacco. There is an approximate 90% risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30% risk in pre-school children. Only 5%-10% of adults become persistent carriers following infection. Of individuals persistently infected with HBV, 10%-30% will develop liver cirrhosis and HCC. These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological, viral or environmental factors. Thus, differences in host genetic factors may affect the natural history of hepatitis B.

CCR5 on the NK Cells and its Ligand (RANTES) Expressions are Disrupted in South-Eastern Iranian Patients With Chronic Hepatitis B Infection

Background:

CCR5 is a receptor for CCL3 (MIP-1 α), CCL4 (MIP-1 α) and CCL5 (regulated on activation normal T cell expressed and secreted (RANTES)) and play important roles in recruitment of NK cells to the HBV infected liver.

Objectives:

The main purpose of this study was to investigate the expression levels of CCR5 on the NK cells and also serum levels of RANTES in chronic HBV infected (CHI) patients.

Materials and Methods:

In this descriptive study 63 CHI patients and 96 healthy controls were evaluated regarding CCR5 expression on the NK cells and serum levels of RANTES using flow cytometry and ELISA techniques, respectively. Real-Time PCR technique also was used for HBV-DNA quantification.

Results:

The results revealed that CCR5 expressing NK cells and serum levels of RANTES were decreased significantly in the CHI patients in compare to healthy control.

Conclusions:

Based on the results it can be concluded that NK cells of Iranian CHI patients are unable to express adequate levels of CCR5 and expression levels of RANTES by immune cells also are defected in CHI patients, hence, the migration of NK cells to the infected hepatocytes and HBV eradication from the cells is interrupted.

CCR5 plays important roles in hepatitis B infection

In humans, hepatitis B virus (HBV) is the most prevalent and the main infectious agent that leads to liver disease. Previous investigations identified that long-term HBV-infected patients are unable to eradicate HBV completely from hepatocytes. The main mechanisms responsible for long-term forms of the infections are yet to be clarified. However, researchers believe that the differences in genetic and immunological parameters in the patients in comparison to subjects who successfully clear HBV infections may be the causes for long-term infection. Previous studies demonstrated that chemokines play important roles in the regulation of immune cell migration and activation, which is crucial for a comprehensive immune response against HBV. RANTES, MIP-1α, and MIP-1β are important CC chemokines which act through CC chemokines receptor 5 (CCR5). This receptor is expressed on several effector immune cells including NK cells, T lymphocytes, and macrophages, and plays a crucial role in the regulation of activation and migration of the immune cells during immune responses against viruses, including HBV. Therefore, alterations in its expression or functions could be associated with attenuated immune responses against HBV. In addition, previous studies identified that a 32 base pair deletion (Δ32) in exon 1, as well as three polymorphisms in the promoter region of the CCR5 gene results in downregulation of the molecule. Previous studies revealed that CCR5 expression was altered in hepatitis B but the role of the CCR5 Δ32 mutation and CCR5 promoter polymorphisms in this disease is controversial. This review addresses the recent information regarding the status of CCR5 expression on immune cells and the association of CCR5 promoter polymorphisms with HBV-infected patients.

Pharmacogenetics of the G protein-coupled receptors

Pharmacogenetics investigates the influence of genetic variants on physiological phenotypes related to drug response and disease, while pharmacogenomics takes a genome-wide approach to advancing this knowledge. Both play an important role in identifying responders and nonresponders to medication, avoiding adverse drug reactions, and optimizing drug dose for the individual. G protein-coupled receptors (GPCRs) are the primary target of therapeutic drugs and have been the focus of these studies. With the advance of genomic technologies, there has been a substantial increase in the inventory of naturally occurring rare and common GPCR variants. These variants include single-nucleotide polymorphisms and insertion or deletions that have potential to alter GPCR expression of function. In vivo and in vitro studies have determined functional roles for many GPCR variants, but genetic association studies that define the physiological impact of the majority of these common variants are still limited. Despite the breadth of pharmacogenetic data available, GPCR variants have not been included in drug labeling and are only occasionally considered in optimizing clinical use of GPCR-targeted agents. In this chapter, pharmacogenetic and genomic studies on GPCR variants are reviewed with respect to a subset of GPCR systems, including the adrenergic, calcium sensing, cysteinyl leukotriene, cannabinoid CB1 and CB2 receptors, and the de-orphanized receptors such as GPR55. The nature of the disruption to receptor function is discussed with respect to regulation of gene expression, expression on the cell surface (affected by receptor trafficking, dimerization, desensitization/downregulation), or perturbation of receptor function (altered ligand binding, G protein coupling, constitutive activity). The large body of experimental data generated on structure and function relationships and receptor-ligand interactions are being harnessed for the in silico functional prediction of naturally occurring GPCR variants. We provide information on online resources dedicated to GPCRs and present applications of publically available computational tools for pharmacogenetic studies of GPCRs. As the breadth of GPCR pharmacogenomic data becomes clearer, the opportunity for routine assessment of GPCR variants to predict disease risk, drug response, and potential adverse drug effects will become possible.

Downregulation of CCR5 expression on the peripheral blood CD8+ T cells of southeastern Iranian patients with chronic hepatitis B infection

Studies indicated that CC receptor 5 (CCR5), as a receptor for CC ligand 3, CCL4, and CCL5, plays important roles in the recruitment of T cytotoxic lymphocytes to the liver of chronic HBV (CHB)-infected patients. The main purpose of this study was to investigate the expression levels of CCR5 on the CD8(+) T lymphocytes of CHB patients. This clinical study was performed on 63 CHB patients and 96 healthy controls. Flow cytometric analysis was performed to examine the expression of CCR5 on CD8(+) T cells of CHB patients. Real-time PCR was also used for HBV-DNA quantification. The results of our study demonstrated that CCR5 expressing T cytotoxic cells were decreased significantly in CHB patients in comparison to healthy control. Based on our results, it can be concluded that the percent of CCR5(+)/CD8(+) T cells in Iranian CHB patients is significantly decreased, hence their migration to the infected liver, and HBV eradication from the hepatocytes is disrupted.

High Serum Levels of TGF-β in Iranians With Chronic HBV Infection

BACKGROUND

The transforming growth factor-β (TGF-β) is an important cytokine with anti-inflammatory properties.

OBJECTIVES

The main purpose of this study was to compare the serum levels of TGF-β in a group of chronic HBV infected (CHB) patients as well as healthy individuals from South-East of Iran.

PATIENTS AND METHODS

Sixty patients with CHB as well as sixty healthy individuals were enrolled in the study. ELISA technique was applied to measure the serum levels of TGF-β in both groups.

RESULTS

Our results revealed that the serum levels of TGF-β were significantly increased in CHB patients in compare to healthy controls.

CONCLUSIONS

According to this result, it may be concluded that high serum levels of TGF-β may be a mechanism by which immune response against HBV is suppressed.

Antiviral therapies: focus on hepatitis B reverse transcriptase

Hepatitis B virus (HBV) is the etiologic agent of mankind's most serious liver disease. While the availability of a vaccine has reduced the number of new HBV infections, the vaccine does not benefit the approximately 350 million people already chronically infected by the virus. Most of the drugs approved by the FDA for the treatment of hepatitis B target the reverse transcriptase (RT or P gene product) and are nucleoside RT inhibitors (NRTIs) that suppress viral replication. However, prolonged monotherapies directed against a single target result in the emergence of viral resistance. HBV genotypic differences affect NRTI resistance, and because the reading frames of the S (surface antigen) and P genes partially overlap, genomic differences that affect the surface of the virus may also alter the viral polymerase sequence, function and drug susceptibility. The scope of this review is to assess the effects of HBV genotypic variation on the development of drug resistance to NRTIs. Some RT residues that vary among different genotypes are in the vicinity of residues that mutate and give rise to NRTI resistance. Interactions between these amino acids can help explain the effect of HBV genotype on the development of NRTI resistance during antiviral therapies, and might help in the design of improved therapeutic strategies.

RANTES gene polymorphisms (-403G>A and -28C>G) associated with hepatitis B virus infection in a Saudi population

Besides the host immune response, genetic and environmental factors play crucial roles in the manifestation of hepatitis B virus (HBV) infection. "Regulated on activation normal T-cell expressed and secreted" factor (RANTES) plays a vital role in CD4(+), CD8(+) T-lymphocyte and dendritic cell activation and proliferation in inflammation. Single nucleotide polymorphisms (SNPs) in the RANTES gene are associated with several viral and non-viral diseases. Association studies have invariably indicated a lack of association between RANTES gene SNPs and HBV infection in ethnic populations, even though RANTES gene SNPs exhibit distinct ethnic distributions. Despite the high prevalence of HBV infections in Saudi Arabia, no studies have been made concerning a possible relationship between RANTES gene polymorphisms and susceptibility to and progression of HBV infection. We examined -403G>A and -28C>G RANTES gene variants in 473 healthy controls and 484 HBV patients in ethnic Saudi populations. Significant differences were found in the genotype and allele distributions of the SNPs between the controls and the HBV patients. Both SNPs were significantly linked to viral clearance in these subjects. Our data demonstrate for the first time in a Saudi population, a relationship between the RANTES gene polymorphisms and the clinical course of HBV infection and underscore the importance of evaluating the genetic background of the affected individual to determine how it may affect disease progression.

Hepatitis B virus coinfection negatively impacts HIV outcomes in HIV seroconverters

BACKGROUND

Understanding the impact of hepatitis B virus (HBV) in human immunodeficiency virus (HIV) coinfection has been limited by heterogeneity of HIV disease. We evaluated HBV coinfection and HIV-related disease progression in a cohort of HIV seroconverters.

METHODS

Participants with HIV diagnosis seroconversion window of ≤ 3 years and serologically confirmed HBV infection (HB) status were classified at baseline into 4 HB groups. The risk of clinical AIDS/death in HIV seroconverters was calculated by HB status.

RESULTS

Of 2352 HIV seroconverters, 474 (20%) had resolved HB, 82 (3%) had isolated total antibody to hepatitis B core antigen (HBcAb), and 64 (3%) had chronic HB. Unadjusted rates (95% confidence intervals [CIs]) of clinical AIDS/death for the HB-negative, resolved HB, isolated HBcAb, and chronic HB groups were 2.43 (2.15-2.71); 3.27 (2.71-3.84); 3.75 (2.25-5.25); and 5.41 (3.41-7.42), respectively. The multivariable risk of clinical AIDS/death was significantly higher in the chronic HB group compared to the HB-negative group (hazard ratio [HR], 1.80; 95% CI, 1.20-2.69); while the HRs were increased but nonsignificant for those with resolved HB (HR, 1.17; 95% CI, .94-1.46) and isolated HBcAb (HR, 1.14; 95% CI, .75-1.75).

CONCLUSIONS

HBV coinfection has a significant impact on HIV outcomes. The hazard for an AIDS or death event is almost double for those with chronic HB compared, with HIV-monoinfected persons.

Analytical and clinical performances of a restriction fragment mass polymorphism assay for detection and genotyping of a wide spectrum of human papillomaviruses

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry-based restriction fragment mass polymorphism (RFMP) assay was adapted to human papillomavirus (HPV) genotyping. The analytical sensitivity and the clinical utility were evaluated by testing defined HPV genome equivalents and a total of 426 specimens composed of normal cytology, atypical squamous cells of undetermined significance, low grade squamous intraepithelial lesion, high grade squamous intraepithelial lesion and invasive squamous cell carcinoma. The RFMP assay was able to detect 38.4-114.6 genomic equivalents of a wide variety of HPV types. The RFMP assay detected 34 different HPV genotypes in cervical samples of which 8% were found to be multiple-type infections. The high-risk HPV positivity rate according to the histological diagnosis was 7.9% (8/101), 31.7% (38/120), 50% (55/110), 86% (37/43), 96.2% (50/52) in normal, atypical squamous cells of undetermined significance, low grade squamous intraepithelial lesion, high grade squamous intraepithelial lesion and squamous cell carcinoma subgroups, respectively. Diagnostic sensitivities/specificities for the cervical lesions of squamous cell carcinoma and high grade squamous intraepithelial lesion or worse histology were found to be 96.2%/92.1% and 91.6%/92.1%, respectively. The sensitivity, accuracy, wide range of genotype identification and high-throughput capacity with cost-effectiveness of the test consumables make the RFMP assay suitable for mass screening and monitoring of HPV-associated cervical cancer.

Polymorphisms of CCL3L1/CCR5 genes and recurrence of hepatitis B in liver transplant recipients

BACKGROUND

The genetic diversity of chemokines and chemokine receptors has been associated with the outcome of hepatitis B virus infection. The aim of this study was to evaluate whether the copy number variation in the CCL3L1 gene and the polymorphisms of CCR5Δ32 and CCR5-2459A→G (rs1799987) are associated with recurrent hepatitis B in liver transplantation for hepatitis B virus infection-related end-stage liver disease.

METHODS

A total of 185 transplant recipients were enrolled in this study. The genomic DNA was extracted from whole blood, the copy number of the CCL3L1 gene was determined by a quantitative real-time PCR based assay, CCR5Δ32 was detected by a sizing PCR method, and a single-nucleotide polymorphism in CCR5-2459 was detected by restriction fragment length polymorphism PCR.

RESULTS

No CCR5Δ32 mutation was detected in any of the individuals from China. Neither copy number variation nor polymorphism in CCR5-2459 was associated with post-transplant re-infection with hepatitis B virus. However, patients with fewer copies (<4) of the CCL3L1 gene compared with the population median in combination with the CCR5G allele had a significantly higher risk for recurrent hepatitis B (odds ratio=1.93, 95% CI: 1.00-3.69; P=0.047).

CONCLUSION

Patients possessing the compound decreased functional genotype of both CCL3L1 and CCR5 genes might be more likely to have recurrence of hepatitis B after transplantation.

Concordance of CCR5 genotypes that influence cell-mediated immunity and HIV-1 disease progression rates

We used cutaneous delayed-type hypersensitivity responses, a powerful in vivo measure of cell-mediated immunity, to evaluate the relationships among cell-mediated immunity, AIDS, and polymorphisms in CCR5, the HIV-1 coreceptor. There was high concordance between CCR5 polymorphisms and haplotype pairs that influenced delayed-type hypersensitivity responses in healthy persons and HIV disease progression. In the cohorts examined, CCR5 genotypes containing -2459G/G (HHA/HHA, HHA/HHC, HHC/HHC) or -2459A/A (HHE/HHE) associated with salutary or detrimental delayed-type hypersensitivity and AIDS phenotypes, respectively. Accordingly, the CCR5-Δ32 allele, when paired with non-Δ32-bearing haplotypes that correlate with low (HHA, HHC) versus high (HHE) CCR5 transcriptional activity, associates with disease retardation or acceleration, respectively. Thus, the associations of CCR5-Δ32 heterozygosity partly reflect the effect of the non-▵32 haplotype in a background of CCR5 haploinsufficiency. The correlations of increased delayed-type hypersensitivity with -2459G/G-containing CCR5 genotypes, reduced CCR5 expression, decreased viral replication, and disease retardation suggest that CCR5 may influence HIV infection and AIDS, at least in part, through effects on cell-mediated immunity.

Hepatitis B virus acquisition and pathogenesis in childhood: host genetic determinants

The clinical course of hepatitis B virus (HBV) infection varies from spontaneous recovery to chronic persistent infection leading to severe liver injury. Mounting evidence has recently highlighted the influence of host genotype in the complex interplay between viral and host factors. Studies in adults have suggested the existence of a genetic predisposition to HBV infection secondary to certain defects in the host response. These defects include opsonic deficiency, compromised antigen processing and presentation by human leucocyte antigen variations, attenuated T- and B-cell response, impaired cytokine and chemokine release, and production of receptors for several pertinent factors such as vitamin D and estrogen. By contrast, little is known about the genetic factors involved in the susceptibility to HBV transmission in early childhood. Herein, we review the literature regarding the association between host genetics and susceptibility to primary HBV infection, and we discuss the prospects of investigation in this field. A better understanding of HBV infection immunopathogenesis in the critical period of infancy may allow the development of optimal and innovative prevention and treatment.

Viral hepatitis: human genes that limit infection

Treatment response and susceptibility to chronic viral hepatitis C and B may be modified by host genetic factors. The majority of genetic variants that confer a significant risk have been localized in genes involved in immune response. However, many findings could not be replicated and almost none of the identified risk factors had a noticeable impact on clinical decisions. In contrast, recent findings in independent large genome wide association studies confirmed genetic variants in the interferon gamma gene locus as strong predictors of outcome with outstanding clinical relevance. This review gives an overview on significant genetic susceptibility factors for susceptibility and treatment outcome in chronic viral hepatitis C and B that have been identified by the classical candidate gene approach and genome wide studies and also highlights some recent findings on genetic factors for common adverse drug reactions.

Association between polymorphism of tumor necrosis factor-alpha promoter and response to lamivudine treatment in patients with chronic hepatitis B

BACKGROUND

TNF-alpha promoter polymorphism is known to play an important role in the immunopathogenesis of infection of hepatitis B virus.

AIMS

We investigated whether polymorphisms of TNF-alpha promoter at position -308 or -238 had associations with the response to lamivudine treatment.

METHODS

A total of 89 healthy subjects (control group) and 225 patients with chronic hepatitis B treated with lamivudine were included in this study. Polymorphisms of TNF-alpha promoter at position -308 and -238 were analyzed by polymerase chain reaction. Recruited patients were classified according to the outcome of lamivudine treatment into the responder (103 patients) or non-responder (122 patients) group.

RESULTS

The numbers of A allelic polymorphism of TNF-alpha promoter at position -238 were four (2.2%) in the control, five (2.4%) in the responder and 19 (7.8%) in the non-responder group. The A allele was noted significantly more frequently in the responder than non-responder group (P = 0.012). At position -308, a significant difference was observed between the control group (14; 7.9%) and total chronic hepatitis B patients (15; 3.3%) (P = 0.015).

CONCLUSIONS

Our study demonstrated that the non-response to lamivudine treatment in patients with chronic hepatitis B might be related to the A allelic polymorphism of TNF-alpha promoter at position -238.

Association of CCR5-Δ32 polymorphism with HBV infection in special population of Guizhou Province

AIM: To investigate the distribution of CCR5-Δ32 polymorphism in Han nationality, Yi and Yao minorities of Guizhou and analyze the association between CCR5-Δ32 polymorphism and HBV infection.

METHODS: Blood samples were taken from 92 Chinese Yi ethic individuals in Qianxi, 101 Chinese Yi ethic individuals in Weining, 138 Chinese Yao ethic individuals in Libo and 165 Chinese Han ethic individuals in Bijie. The coding region of the CCR5 gene was amplified by PCR and resolved by agarose gel electrophoresis to analyze the polymorphism of CCR5-Δ32. DNA sequencing was performed to verify the above results.

RESULTS: The 32-base pair deletion allele in the CCR5 gene was not found in all 496 samples. DNA sequencing verified that no CCR5-Δ32 allele was detected in all samples.

CONCLUSION: No CCR5-Δ32 allele is detected in this study in special population of Guizhou Province though the distribution of CCR5-Δ32 allele has geographical and ethnic differences.

Genetic interactions between the donor and the recipient for susceptibility to acute rejection in kidney transplantation: polymorphisms of CCR5

BACKGROUND

Acute rejection (AR) contributes to the development of chronic allograft nephropathy that is the major cause of graft failure. We analyzed the 59029G>A polymorphism and an internal 32 bp deletion (CCR5 32) of CCR chemokine receptor 5 (CCR5) Delta and tried to prove the hypothesis that genetic interactions between the donor and the recipient influence the development of AR.

METHODS

We detected genetic polymorphisms by the TaqMan(R) method and by sizing PCR amplicons (n = 486). The primary outcomes were early acute rejection (EAR) and repeated early acute rejection (RR). We defined EAR as the occurrence of a biopsy-proven AR within 3 months after transplantation.

RESULTS

The development of EAR was dependent on the number of A alleles in recipients and showed a dose-response relationship (P = 0.002). When we combined the number of A alleles in both donor and recipient, episodes of EAR and RR were more prevalent as the allelic number increased (A allelic number 0 & 1, 2 versus 3 & 4, P = 0.048; 0 & 1 versus 3 & 4, P = 0.006). Statistical significance was preserved after multivariate analysis of sex, HLA mismatch and type of donor with the recipient's age as the continuous term. Also, graft survival was different according to the presence of the A allele, i.e. recipients carrying A allele (+) grafts showed poor graft survival (P = 0.008 by a log-rank test). Again, the number of A alleles affected graft survival as the recipients who carried more A alleles had poor graft survival (A allele number 0 & 1 versus 2 versus 3 & 4, P = 0.011; 0 & 1 versus 3 & 4, P = 0.08; 0 & 1 versus 2, P = 0.002; by a log-rank test). All of the participants were wild-type homozygotes for CCR5Delta32.

CONCLUSIONS

The A allele of CCR5 59029G>A was a risk factor for EAR and RR. As the number of A alleles increased, episodes of EAR were more frequently observed.

Interaction between RANTES promoter variant and CCR5Delta32 favors recovery from hepatitis B

Recovery from acute hepatitis B virus (HBV) infection occurs in 95% of adult-acquired infections. A 32-bp deletion in CCR5 (CCR5Delta32), which encodes for a nonfunctional receptor, increases the likelihood of recovery. Using 181 subjects with persistent HBV infection and 316 who had recovered, we tested the hypothesis that an epistatic interaction between functional polymorphisms in RANTES (a CCR5 ligand) and CCR5 impacts recovery. Specific models designed to assess individual contributions of compound genotypes demonstrated that the only combination associated with recovery from an HBV infection was RANTES -403A with CCR5Delta32 (odds ratio 0.36, p = 0.02). Because the phenotypic consequence of -403A is reported to be higher levels of RANTES, we propose a model in which excess RANTES in combination with low CCR5 favors recovery from an HBV infection, which will require validation through functional testing.

High-resolution human papillomavirus genotyping by MALDI-TOF mass spectrometry

We describe a matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS)-based assay for human papillomavirus (HPV) genotyping--the restriction fragment mass polymorphism (RFMP) assay, which is based on mass measurement of genotype-specific oligonucleotide fragments generated by TypeIIS restriction endonuclease cleavage after recognition sites have been introduced by PCR amplification. The use of a TypeIIS restriction enzyme makes the RFMP assay independent of sequence and applicable to a wide variety of HPV genotypes, because these enzymes have cleavage sites at a fixed distance from their recognition sites. After PCR amplification, samples are subjected to restriction enzyme digestion with FokI and BtsCI and desalting using Oasis purification plates, followed by analysis by MALDI-TOF MS. Overall, the protocol is simple, takes approximately 4-4.5 h and can accurately detect and identify at least 74 different HPV genotypes.

Polymorphisms of microsomal triglyceride transfer protein in different hepatitis B virus-infected patients

AIM: To identify the two polymorphisms of microsomal triglyceride transfer protein (MTP) gene in the Chinese population and to explore their correlation with both hepatitis B virus (HBV) self-limited infection and persistent infection.

METHODS: A total of 316 subjects with self-limited HBV infection and 316 patients with persistent HBV infection (195 subjects without familial history), matched with age and sex, from the Chinese Han population were enrolled in this study. Polymorphisms of MTP at the promoter region -493 and at H297Q were determined by the allele specific polymerase chain reaction (PCR).

RESULTS: The ratio of males to females was 2.13:1 for each group and the average age in the self-limited and chronic infection groups was 38.36 and 38.28 years, respectively. None of the allelic distributions deviated significantly from that predicted by the Hardy-Weinberg equilibrium. There was a linkage disequilibrium between H297Q and -493G/T (D’ = 0.77). As the χ² test was used, the genotype distribution of MTP-493G/T demonstrated a significant difference between the self-limited infection group and the entire chronic group or the chronic patients with no family history (χ² = 8.543, P = 0.015 and χ² = 7.199, P = 0.019). The allele distribution at the MTP-493 position also demonstrated a significant difference between the study groups without family history (χ² = 6.212, P = 0.013). The T allele emerged as a possible protective factor which may influence the outcomes of HBV infection (OR: 0.59; 95% CI: 0.389-0.897).

CONCLUSION: The polymorphism of the MTP gene, T allele at -493, may be involved in determining the HBV infection outcomes, of which the mechanism needs to be further investigated.

High prevalence of significant histology in asymptomatic chronic hepatitis B patients with genotype C and high serum HBV DNA levels

Current treatment guidelines suggest that antiviral therapy be considered for chronic hepatitis B (CHB) patients with high viral load if a biopsy shows significant liver disease despite alanine aminotransferase (ALT) levels two times or less than the upper limit of normal (ULN). We evaluated the histological findings in CHB patients with high viral load and persistently normal or slightly elevated serum ALT levels. Between January 2003 and June 2006, 105 consecutive treatment-naive patients with CHB who underwent ultrasonography-guided percutaneous liver biopsy, had detectable serum HBV DNA (>10(5) copies/mL) in a direct hybridization assay and normal or slightly elevated serum ALT levels (≤2 × ULN) for at least 12 months were included in a prospective study. Histological assessment was based on the METAVIR scoring system. Significant histology was defined as fibrosis stage ≥F2 or necroinflammation grade ≥A2. Among the 105 CHB patients with high viral load and persistently normal or slightly elevated serum ALT levels for at least 12 months, significant fibrosis (F2-F4 fibrosis) was observed in 63 patients (60.0%) and the actual significant histology was found in 65 patients (61.9%). On multivariate analysis, serum ALT levels and age at which they entered the study were independent factors associated with significant histology. Odds ratios for significant histology increased progressively according to serum ALT levels and age. In conclusion, a large proportion of CHB patients with genotype C, high viral load and ALT ≤2 × ULN had significant liver disease on liver biopsy and should be considered for antiviral therapy.

Matrix metalloproteinase-3 genotypes influence recovery from hepatitis B virus infection

The reasons for the viral persistence of hepatitis B virus (HBV) infection are unknown, but are probably related to host immune factors. Several matrix metalloproteinases (MMPs) can regulate an inflammatory response. The aim of this study was to assess the effects of the single nucleotide polymorphisms (SNPs) of MMP-3 and -9 genes on the susceptibility to persistent HBV infection. We studied 489 Korean patients with HBV infection (144 inactive carriers, 182 chronic hepatitis, and 163 liver cirrhosis) and 174 healthy individuals who had recovered from HBV infection. MMP-3 gene SNPs were identified at two polymorphic sites (codon 45 [E45K] and codon 96 [D96D]) and MMP-9 gene SNPs at three polymorphic sites (codon 279 [R279Q], codon 607 [G607G], and codon 668 [Q668R]) in study subjects. The frequency of T allele at third position of codon 96 in the MMP-3 gene was higher in HBV persistence patients when analyzed by co-dominant model (age- and sex-adjusted OR=1.242, 95% CI= 1.001-1.540, p=0.049). In conclusion the T allele at the third position of codon 96 in the MMP-3 gene might be associated with persistent HBV infection.

G protein-coupled receptor pharmacogenetics

Common G protein-coupled receptor (GPCR) gene variants that encode receptor proteins with a distinct sequence may alter drug efficacy without always resulting in a disease phenotype. GPCR genetic loci harbor numerous variants, such as DNA insertions or deletions and single-nucleotide polymorphisms that alter GPCR expression and function, thereby contributing to interindividual differences in disease susceptibility/progression and drug responses. In this chapter, these pharmacogenetic phenomena are reviewed with respect to a limited sampling of GPCR systems, including the beta(2)-adrenergic receptors, the cysteinyl leukotriene receptors, and the calcium-sensing receptor. In each example, the nature of the disruption to receptor function that results from each variant is discussed with respect to the regulation of gene expression, expression on cell surface (affected by receptor trafficking, dimerization, desensitization/downregulation), or perturbation of receptor function (by altering ligand binding, G protein coupling, and receptor constitutive activity). Despite the breadth of pharmacogenetic knowledge available, assessment for genetic variants is only occasionally applied to drug development projects involving pharmacogenomics or to optimizing the clinical use of GPCR drugs. The continued effort by the basic science of pharmacogenetics may draw the attention of drug discovery projects and clinicians alike to the utility of personalized pharmacogenomics as a means to optimize novel GPCR drug targets.