Genetic variants in the CCR gene cluster and spontaneous viral elimination in hepatitis C-infected patients

The Role of Genetic Factors in the Development of Acute Respiratory Viral Infection COVID-19: Predicting Severe Course and Outcomes

The aim of this study was to identify single nucleotide variants in genes associated with susceptibility to or severe outcomes of COVID-19. A total of 319 genomic DNA samples from patients with varying degrees of disease severity and 78 control DNA samples from people who had regular or prolonged contact with patients with COVID-19 but did not have clinical manifestations and/or antibodies to SARS-CoV-2. Seven SNPs were identified that were statistically associated with disease risk or severe course, rs1799864 in the CCR2 gene (OR = 2.21), rs1990760 in the IFIH1 gene (OR = 2.41), rs1800629 in the TNF gene (OR = 1.98), rs75603675 in the TMPRSS2 gene (OR = 1.86), rs7842 in the C3AR1 gene (OR = 2.08), rs179008 in the gene TLR7 (OR = 1.85), rs324011 in the C3AR1 gene (OR = 2.08), rs179008 in the TLR7 gene (OR = 1.85), and rs324011 in the STAT6 gene (OR = 1.84), as well as two variants associated with protection from COVID-19, rs744166 in the STAT3 gene (OR = 0.36) and rs1898830 in the TLR2 gene (OR = 0.47). The genotype in the region of these markers can be the criterion of the therapeutic approach for patients with COVID-19.

Regulation and functional roles of chemokines in liver diseases

Inflammation is a major contributor to the pathogenesis of almost all liver diseases. Low-molecular-weight proteins called chemokines are the main drivers of liver infiltration by immune cells such as macrophages, neutrophils and others during an inflammatory response. During the past 25 years, tremendous progress has been made in understanding the regulation and functions of chemokines in the liver. This Review summarizes three main aspects of the latest advances in the study of chemokine function in liver diseases. First, we provide an overview of chemokine biology, with a particular focus on the genetic and epigenetic regulation of chemokine transcription as well as on the cell type-specific production of chemokines by liver cells and liver-associated immune cells. Second, we highlight the functional roles of chemokines in liver homeostasis and their involvement in progression to disease in both human and animal models. Third, we discuss the therapeutic opportunities targeting chemokine production and signalling in the treatment of liver diseases, such as alcohol-associated liver disease and nonalcoholic steatohepatitis, including the relevant preclinical studies and ongoing clinical trials.

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.

Association of genetic polymorphisms of chemokines and their receptors with clearance or persistence of hepatitis C virus infection

BACKGROUND

Polymorphisms of certain genes may have an effect on either persistence of infection or spontaneous clearance of hepatitis C virus (HCV). We hypothesized that one or more variants of chemokines (CCL2 and CCL5) and chemokine receptors (CC chemokine receptor type 2 [CCR2]) genes are associated with the susceptibility to HCV infection.

METHODS

We recruited 1460 patients with chronic HCV (CHC), 108 subjects with spontaneous virus clearance (SVC) and 1446 individuals as a healthy control group. All were genotyped for single nucleotide polymorphisms: rs13900 C/T of CCL2, rs3817655 T/A of CCL5 and rs743660 G/A and rs1799864 G/A of CCR2 using allelic discrimination real-time PCR technique.

RESULTS

The carriage of the A allele of CCR2 rs743660 was significantly higher in CHC compared to SVC (odds ratio [OR] 4.03) and to controls (1.42) and in controls compared to SVC (2.85) (all P < 0.01). Similarly, the A allele of CCR2 rs1799864 was significantly higher in the CHC group when compared with both SVC (1.97) and controls (2.13) (both P < 0.01), but the OR between controls and SVC was not significant (1.08, P = 0.723). Carriage of C allele of CCL2 rs13900 and the T allele of CCL5 rs3817655 were significantly higher in SVC group when compared with both CHC (OR = 0.19 and OR = 0.24, respectively) and control groups (OR = 0.65 and OR = 0.45, respectively [all P < 0.01]).

CONCLUSIONS

Susceptibility to HCV infection is associated with A alleles of both (rs743660 and rs1799864 G/A) of CCR2 while spontaneous clearance of HCV is associated with the C allele of rs13900 of CCL2 and T allele of rs3817655 of CCL5.

Homozygosity for HLA group 2 alleles predicts treatment failure with interferon-α and ribavirin in chronic hepatitis C virus genotype 1 infection

Host genetic factors influence treatment responses to antiviral therapy in chronic hepatitis C virus (HCV) infection. We retrospectively investigated associations between host genetic markers and treatment-induced virologic responses to dual therapy with interferon-α and ribavirin in chronically infected HCV genotype 1 (g1)- and genotype 3 (g3)-infected individuals. A total of 171 patients (89 HCV g1 and 82 HCV g3 infected) were investigated for genetic markers influencing treatment-induced sustained virologic response (SVR). Overall, SVR was observed for 46/89 (52%) HCV g1- and 57/82 (70%) HCV g3-infected patients. Of the 4 interleukin 28B (IL28B) single-nucleotide polymorphisms (SNPs), rs12979860 was the host genetic marker most significantly associated with failure to achieve an SVR in HCV g1-infected individuals [P=3.83×10(-4); odds ratio (OR)=5.61; confidence interval (CI)=2.07-15.18] and gave a positive predictive value for treatment failure of 81.3% for minor homozygotes (TT). Using additive (P=3.54×10(-4)) and dominant models (P=3.83×10(-4)), a dosage effect of the T allele was observed, with the dominance term not significant for this SNP. Logistic regression showed an association between HLA-C1/C1 and rapid virologic response in HCV g1 infections with an OR relative to the heterozygote of 10.0 (95% CI: 1.6-62.5, P=0.014). HLA-C2 homozygosity was a significant predictor of nonresponse to treatment in HCV g1-infected individuals (P=0.023).

Effects of the Chemokine Receptor 5 (CCR5)-Delta32 Mutation on Hepatitis C Virus-Specific Immune Responses and Liver Tissue Pathology in HCV Infected Patients

BACKGROUND

The specific antiviral T cells provide CC chemokine receptor 5 (CCR5) for the immune response during the hepatitis C virus (HCV) infection. Heterogenous and/or homozygous 32 base pair deletion in CCR5 gene (CCR5Δ32 bpdel) leads to reduced protein expression.

OBJECTIVES

In the current case control study, we aimed to compare the histopathological findings of liver to the CCR5Δ32 bpdel mutation profiles, expression and some other clinical findings in patients with chronic HCV infection.

MATERIALS AND METHODS

Multiple Strip Assay reverse hybridisation and Real Time PCR techniques were used to determine the germline CCR5 mutations and immunohistochemical technique was used to evaluate the gene expression in targer tissue biopsies.

RESULTS

Target CCR5 WT/WT, WT/Δ32, and Δ32/Δ32 genotypes were observed in 91.4%, 8.6% and 0.0% for HCV positive patients and 98.3%, 1.7% and 0.0% for control group respectively. The histologic activity index (HAI) was significantly lower (4.0 ± 1.0) in the mutated group than the non-mutated group (5.7 ± 1.0). Decreased fibrosis levels were detected in HCV positive mutated group.

CONCLUSIONS

Results showed that CCR5 polymorphism was more frequent in HCV positive patients than in healthy population in Turkish population. Current results also showed that mutated CCR5 signalling pathway due to CCR5-Delta32 may potentially result in subtle reduction of HCV specifity to the drug responses due to the positive impact on liver inflammation, fibrosis levels and liver destruction in HCV infection.

CCR5-Δ32 genotype does not improve predictive value of IL28B polymorphisms for treatment response in chronic HCV infection

IL28B polymorphisms strongly predict spontaneous and treatment-induced clearance of hepatitis C virus (HCV) infection. A recent study proposed a 32-base pair deletion in the CC-chemokine receptor 5 (CCR5) gene (CCR5-Δ32) interacting with the IL28B polymorphisms to influence spontaneous HCV clearance. The aim of this study was to clarify the role of CCR5-Δ32 in treatment-induced clearance of chronic hepatitis C (CHC). A cross-sectional cohort of 813 Caucasian patients with CHC genotype 1 (365 responders and 448 non-responders) who had received standard of care dual therapy with interferon (IFN)-α and ribavirin (RBV) was genotyped for the CCR5-Δ32 and IL28B polymorphisms to examine their interaction with respect to treatment response. CCR5-Δ32 did not influence treatment-induced recovery to IFN-α/RBV in CHC, and did not improve prediction of sustained virological response in the context of the IL28B polymorphisms in a multivariate model. CCR5-Δ32 homozygotes were significantly more frequent in those with CHC than healthy controls in the European cohorts (2.9% vs 0.4%, P<0.0001), but not in Australians of European ancestry. In conclusion, CCR5-Δ32 does not influence treatment response in the context of IL28B polymorphisms. Although CCR5-Δ32 may affect viral clearance within closely controlled geographical and genetic environments, we found no effect in larger cohorts treated with dual therapy.

Association between low molecular polypeptide 7 single nucleotide polymorphism and response to therapy in hepatitis C virus infection

AIM

To investigate the relationship between low molecular polypeptide-7 (LMP-7) gene polymorphism and response to interferon (IFN) therapy in chronic hepatitis C virus (HCV) patients.

METHODS

LMP-7 polymorphism at codon 49 with nucleotide substitution from A to C was amplified in 104 chronic HCV patients of genotype 4. The amplicons were digested with restriction endonuclease BsmI and the produced restriction fragment length polymorphism was analyzed. Patients received IFN + regional blood volume therapy for 48 wk and the frequency of this single nucleotide polymorphism (SNP) was statistically correlated with treatment response. The exclusion criteria for these patients were stated by the national health program for treating viral hepatitis. Main exclusion criteria included co-infection with hepatitis B virus or schistosomiasis, thyroid dysfunction, uncontrolled diabetes mellitus, history of long term drug or alcohol intake and autoimmune hepatitis. Multivariate analyses were done to correlate LMP-7 SNP plus several factors such as age, gender, weight, serum alpha-fetoprotein (AFP) and alanine aminotransferase levels, liver activity, fibrosis score and viral load with response to therapy.

RESULTS

The data presented in this study clearly demonstrated statistically significant differences between sustained virological response (SVR) (defined as the absence of HCV RNA levels in the patient's sera at least 6 mo after discontinuation of treatment) and non-response (NR) (where HCV RNA levels in the patient's sera never become undetectable for 6 mo during or after treatment). Variables were described as odds ratio with 95%CI. The data were considered significant if P values were ≤ 0.05; highly significant if P < 0.01 and very highly significant if P < 0.001. Current data showed that 91.7% of patients carrying LMP-7 C/C allele were associated with SVR, while the other two genotypes C/A and A/A were associated with NR patients, 83.3% and 64.3% respectively, showing that genotype CC was strongly associated with response to interferon (95%CI: 12.0719-134.6572, P = 0.0001). The majority of parameters recorded in SVR and NR patients included higher values of mean age (P = 0.004), alanine aminotransferase (P = 0.001), AFP (P = 0.001), body weight (P = 0.025), viral load (P = 0.025), higher fibrosis and histological activity index indices among NR vs SVR patients. Also, the multivariate statistical analysis of the different factors of fibrosis score, liver activity grade, genotypes and alleles of LMP-7 gene polymorphism in responders and NRs of HCV patients in this study showed that HCV patients with A allele had a very highly significant association with the NRs, high fibrosis and higher liver activity, while the C allele had a very highly significant association with the responders, low fibrosis and lower liver activity (95%CI: 3.5800-13.2519, P = 0.0001).

CONCLUSION

LMP-7 SNP is a candidate gene that should be considered when designing a mathematical model for predicting response to therapy and disease progression in HCV patients.

The predictive value of IL28B gene polymorphism for spontaneous clearance in a single source outbreak cohort is limited in patients carrying the CCR5Δ32 mutation

BACKGROUND & AIMS

The CCR5Δ32 mutation has been suspected to adversely affect outcomes of HCV infection, although reports have remained controversial. Here, we investigated the relative genetic contributions of the CCR5Δ32 deletion and the IL28B rs12979860 polymorphisms to spontaneous clearance of hepatitis C in a single-source outbreak.

METHODS

We retrieved 396 Caucasian women (119 women with spontaneous HCV clearance) who had been infected with HCV genotype 1-contaminated anti-D immunoglobulin in 1978, and determined their IL28B and CCR5 alleles.

RESULTS

IL28B CC, CT, and TT genotypes were found in 35.4%, 50%, and 14.6% of patients and corresponded to spontaneous clearance rates of 50%, 21.2%, and 12.1% (Chi(2)=38.7, p=5.0×10(-10)), respectively. CCR5 WT/WT, WT/Δ32, and Δ32/Δ32 genotypes were observed in 76%, 22.7%, and 1.3% of patients and corresponded to clearance rates of 33.2%, 21.2%, and 0% (Chi(2)=6.9, p=0.009), respectively. In a stepwise forward-conditional multivariate regression model both CCR5 (OR 2.1, p=0.01 for WT/WT) and IL28B genetic variants (OR 4.3, p=4.6×10(-10) for the C/C genotype) were identified as independent predictors of spontaneous HCV clearance. Importantly, favorable response rates were associated with the IL28B CC genotype only in CCR5 wild-type homozygous women, while HCV clearance in CCR5Δ32 carriers remained poor even in patients with the rs12979860 CC genotype.

CONCLUSIONS

Both IL28B rs1297860 and CCR5Δ32 allelic variants are independent genetic determinants of spontaneous HCV clearance. The variable relative distribution between IL28B rs1297860 and CCR5Δ32 allelic variants in different populations may have masked the role of the CCR5Δ32 mutation in some studies.

Genes and hepatitis C: susceptibility, fibrosis progression and response to treatment

Hepatitis C virus contact and infection show three different phenotypes: spontaneous viral clearance (SVC), chronic hepatitis C (CHC) and sustained virological response (SVR) following antiviral treatment. Many factors, including genetics, influence the evolution of these three phenotypes. We performed a literature search (PubMed) up to 31 January 2010 without language restriction to identify relevant studies on genes and hepatitis C. Additional studies were sought by reviewing the reference lists of the identified articles. Meta-analysis (using Meta-disk 1.4) was conducted to evaluate the association of single nucleotide polymorphism (SNP) in the IL28B region and SVR. The candidate gene approach showed strong relationships between human leucocyte antigen class II (DQB1(*) 0301 and DRB1(*) 1101) and SVC. A cirrhosis risk score involving 7 SNPs has been validated recently. The set of odds ratios of studies demonstrated an association between SNP (rs12987960/rs8099917) in the IL28B and SVR in CHC treated with peginterferon plus ribavirin (OR: 4.6; 95% CI: 2.9-7.3). The overall distribution of protective allele correlated with ethnic differences in SVR (Asians, Europeans, Hispanic and Afro-Americans) together with SVC, but not with fibrosis stage or viral load. These polymorphisms did not influence SVR in very-easy-to-treat patients such as genotype 2/3, rapid virological responders or patients with acute hepatitis C. While the genetic fingerprint for fibrosis progression remains elusive, IL28b polymorphism predicts SVC and SVR. However, nearly half of patients achieving SVR did not show favourable genotype. Further genetic signals are warranted to complete the puzzle of factors influencing hepatitis C.

Virus-host interactions in hepatitis C virus infection: implications for molecular pathogenesis and antiviral strategies

With a global burden of 170 million chronically infected patients and a major cause of liver cirrhosis and hepatocellular carcinoma, hepatitis C virus (HCV) is a major public health challenge. Recent discoveries of viral and cellular factors mediating virus-host interactions have allowed scientists to uncover the key molecular mechanisms of viral infection and escape from innate and adaptive immune responses. These include the discovery of tight junction proteins as entry factors and microRNA-122, cyclophilins and lipoproteins as host factors for virus translation, replication and production. Furthermore, global genetic analyses have identified IL-28B as a genetic factor associated with the outcome of HCV infection. These discoveries markedly advance the understanding of the molecular pathogenesis of HCV infection and uncover novel targets for urgently needed antiviral strategies.

Role of host genetic factors in the outcome of hepatitis C virus infection

The natural history of hepatitis C virus (HCV) infection is determined by a complex interplay between host genetic, immunological and viral factors. This review highlights genes involved in innate and adaptive immune responses associated with different outcomes of HCV infection. For example, an association of HCV clearance with certain HLA alleles has been demonstrated. The mechanisms responsible for these associations have been linked to specific T cell responses for some particular alleles (e.g., HLA-B27). Genetic associations involved in T cell regulation and function further underline the role of the adaptive immune response in the natural history of HCV infection. In addition, some genes involved in innate NK cell responses demonstrate the complex interplay between components of the immune system necessary for a successful host response to HCV infection.

Recognition of genetic factors influencing the progression of hepatitis C : potential for personalized therapy

Infection with hepatitis C virus (HCV) is a major cause of chronic liver disease. Hepatic fibrosis may develop in subjects with chronic HCV infection, culminating in cirrhosis and an increased risk of hepatocellular carcinoma. The rate of development of fibrosis varies substantially between individuals; while it is influenced by a number of demographic and environmental factors, these account for only a small proportion of the variability. There are no clinical markers or tests that predict the rate of fibrosis progression in an individual subject. Thus, there has been increasing interest in the influence of host genetic factors on the rate of disease progression, and whether a genetic signature can be developed to reliably identify individuals at risk of severe disease. Numerous case-control, candidate gene, allele-association studies have examined the relationship between host single nucleotide polymorphisms or other genetic mutations and fibrosis in patients with chronic HCV infection. However, these studies have generally been irreproducible and disappointing. As seen with genetic studies for other diseases, small study cohorts and poor study design have contributed to limited meaningful findings. The successful determination of genetic signatures for fibrosis progression in chronic HCV will require multicenter collaborations using genome-wide association studies, with large, phenotypically well-defined sample sets. While these studies will require a significant financial commitment, a successful outcome offers the potential for personalized therapy and better patient management.

CCL2-2518 A/G and CCR2 190 A/G do not influence the outcome of hepatitis C virus infection in the Spanish population

AIM: To assess whether CCL2 or interactions between this chemokine and its receptor (CCR2) are associated with outcomes of chronic hepatitis C and with responses to antiviral therapy.

METHODS: Two hundred and eighty-four patients with chronic hepatitis C and 193 non-infected matched controls were included in this study. Patients were categorized according to their Scheuer score of hepatic fibrosis as F0-F2 (n = 202) or F3-F4 (n = 82) and according to their response to anti-Hepatitis C virus (HCV) therapy as sustained response (SR, n = 101) or non-sustained response (NSR, n = 98). Genotyping of the -2518 (A/G) CCL2 was performed using PCR-RFLP, genotyping of the 190 (A/G) CCR2 using a PCR-ARMS system, and genotyping of the rs3138042 (G/A) CCR2 using Taqman probes.

RESULTS: Univariate analyses identified 4 parameters (infection duration time, viral genotype, gender and AST levels) that tended to influence fibrosis and 7 parameters (CCL2G, CCL2ACCR2A, viremia levels, fibrosis stage, viral genotype, infection duration time and AST levels) that significantly influenced or tended to influence response to treatment. Multivariate analysis identified gender and AST levels as parameters that independently influenced fibrosis stage and viral genotype and infection duration time were the two parameters that independently influenced response to treatment.

CONCLUSION: Our results indicate that the mutations studied in the gene pair CCL2/CCR2 do not play a major role in the outcome and response to treatment for HCV infection in the Spanish population.

Assessing Theoretical Risk and Benefit suggested by Genetic Association Studies of CCR5: Experience in a Drug Development Programme for Maraviroc

The proliferation of published gene association studies of the CCR5A32 mutation is of relevance to drug development of a CCR5 antagonist for HIV, in highlighting potential safety concerns. We conducted an initial review of all non-HIV gene association studies of CCR5-Δ32, followed by detailed meta-analyses in the three disease areas most commonly reported. Our review indicated no consistent evidence of increased risk of susceptibility to hepatitis C virus infection or multiple sclerosis among individuals with CCR5-Δ32 mutation, and suggested treatment with a CCR5 inhibitor is unlikely to have related adverse effects. There was, however, evidence to suggest rheumatoid arthritis as a potential therapeutic target for a CCR5 antagonist. Clinical evidence would be required to confirm these findings.

Variants of chemokine receptor 2 and interleukin 4 receptor, but not interleukin 10 or Fas ligand, increase risk of cervical cancer

Cervical cancer is caused by persistent infection of oncogenic human papillomavirus (HPV). Most infected women clear the virus without developing cervical lesions and it is likely that immunological host factors affect susceptibility to cervical cancer. The impact of the human leukocyte antigen (HLA) locus on the risk of cervical cancer is established and several other genes involved in immunological pathways have been suggested as biologically plausible candidates. The aim of this study was to examine the potential role of polymorphisms in 4 candidate genes by analysis of 1,306 familial cervical cancer cases and 288 controls. The following genes and polymorphisms were studied: Chemokine receptor 2 (CCR-2) V64I; Interleukin 4 receptor alpha (IL-4R) I75V, S503P and Q576R; Interleukin 10 (IL-10) -592; and Fas ligand (FasL) -844. The CCR-2 64I variant was associated with decreased risk of cervical cancer; homozygote carriers of the 64I variant had an odds ratio of 0.31 (0.12-0.77). This association was detected in both carriers and noncarriers of the HLA DQB1*0602 cervical cancer risk allele. The IL-4R 75V variant was associated with increased risk of cervical tumors, cases homozygote for 75V had an odds ratio of 1.91 (1.27-2.86) with a tendency that the association was stronger in noncarriers of the DQB1*0602 allele. We did not find any association for IL-10 -592, or FasL -844, previously reported to be associated with cervical cancer in the Dutch and Chinese populations, respectively.

CCR5Δ32 mutation does not influence the susceptibility to HCV infection, severity of liver disease and response to therapy in patients with chronic hepatitis C

AIM: To study whether CCR5Δ32 mutation was associated with viral infection and severity of liver disease.

METHODS: Two hundred and fifty two histologically proven, chronic HCV patients (mean age: 41 ± 14 years; M/F: 164/88) were genotyped. PCR based genotyping of 32 bp deletion at the CCR5 locus was done. Four-hundred and eight matched healthy controls were studied to assess susceptibility to HCV infection. To assess correlation of immune gene polymorphism with severity of HCV related liver disease, patients with chronic HCV infection were divided into those with a fibrosis score of ≤ 2 (mild) or > 2 (severe) and histological activity index (HAI) of ≤ 5 or > 5. For correlation between CCR5Δ32 mutations and response to therapy, 129 patients who completed therapy were evaluated.

RESULTS: The majority (89.4%) of the patients were infected with genotype 3. The frequency of homozygous CCR5Δ32 mutants was comparable to HCV patients as compared to the healthy controls (0.7% vs 0%, P = 0.1). Further more, the frequency of CCR5∆32 mutation was comparable in patients with mild or severe liver disease. (P = NS). There was also no association observed with response to therapy and CCR5Δ32 mutation.

CONCLUSION: CCR5Δ32 mutation does not have a role in disease susceptibility, severity or response to therapy in patients with chronic hepatitis C infection.

Protein therapeutics: new applications for pharmacogenetics

Pharmacogenetic studies have traditionally focused on genes involved in processes that affect the pharmacokinetics of small-molecule drugs, such as drug metabolism. However, attention is shifting to the effects of genetic variations in drug targets and associated pathway components on drug responses. We describe how these variations are important for understanding differences in responses to the growing number of protein therapeutics that are entering clinical practice. Pharmacogenetic studies of these drugs are surveyed, and issues important to the success of such endeavours are discussed. As novel protein therapeutics are introduced, we anticipate that the use of pharmacogenetics will assume a key role in their development and clinical application.

Lack of higher frequency of the chemokine receptor 5-delta32/delta32 genotype in hepatitis C

PURPOSE

An elevated frequency of the CCR5-Delta32 mutation in German patients with hepatitis C with viremia has been reported. The aim of the present study was to verify whether this mutation occurs in an Italian population with hepatitis C and whether it is an adverse host factor indicative of severity of liver disease and response to antiviral therapy.

STUDY

The authors amplified 189-bp (wild-type) and 157-bp (Delta32 deletion) fragments of the CCR5 gene by polymerase chain reaction in 130 patients with chronic hepatitis C. Comparisons were drawn with 110 blood donors and 135 patients with primary biliary cirrhosis.

RESULTS

Four (3.1%) patients with chronic hepatitis C and 1 blood donor (0.9%) were CCR5-Delta32 homozygous, whereas there was no CCR5-Delta32 homozygosity among primary biliary cirrhosis patients; the wild-type gene was present in a similar percentage in the 3 groups of patients without any significant difference (83.1% vs 90.4% vs 83.6%, respectively). Among the patients with chronic hepatitis C, no significant correlation was found between CCR5-Delta32 homozygosity and the following parameters: histologic grade/stage, hepatitis C virus genotype, viral load, serum aspartate aminotransferase, serum alanine aminotransferase, and serum gamma-glutamyltransferase. Ninety-five patients received a standard antiviral protocol with pegylated interferon (PEG Intron)+ribavirin; a sustained response was achieved in 59 patients (62.1%), and the remainder did not respond or experienced a relapse. Response to treatment was not influenced by CCR5-Delta32 deletion.

CONCLUSION

No greater frequency of CCR5-Delta32 homozygosity was seen in an Italian population of patients with chronic hepatitis C. This mutation does not seem to influence either the overall severity of liver disease or the response to viral therapy.