A predictive model of treatment outcome in patients with chronic HCV infection using IL28B and PD-1 genotyping

Analysis of Programmed Cell Death-1 (PD-1) Gene Variations (re11568821 and rs41386349) in HTLV-1 Infection Using One Primer Pair and Proviral Load

About 90% of people infected with Human T lymphotropic virus type-1 (HTLV-1) virus are asymptomatic, so it can be said that the prevalence of this virus is not completely clear. During chronic infection, the expression of programmed cell death-1 (PD-1) protein increases and causes exhausted phenotype in T cells. Considering the role of host genetics and immune responses in HTLV-1 infection, in this case-control study, included 81 asymptomatic carriers (ACs) and 162 healthy controls (HCs), rs11568821 and rs41386349 polymorphisms of PD-1 gene were evaluated by Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method which investigated by one primer pair for both polymorphisms also, proviral load (PVL) measured by quantitative real-time PCR (Q-RT-PCR). The results showed that the mutant allele of rs11568821 (A) and rs41386349 (T) polymorphisms is associated with an increase in HTLV-1 infection significantly (p = 0.019 and p = 0.000 respectively). But there was no significant relationship between PVL and polymorphisms.

The Association of Programmed Death 1 Gene Polymorphisms of PD1.3 G/A and PD1.5 C/T with Risk of COVID-19 in an Iranian Population: A Case-Control Study

Programmed death 1 (PD-1) has a central role in maintaining T cell tolerance and terminating cellular responses after eliminating antigens. Variation in PD-1 gene products caused by polymorphisms has been linked to several malignancies and autoimmune diseases. However, there is little known about the effects of its single-nucleotide polymorphisms (SNPs) on viral infections, particularly COVID-19. The primary aim of this study was to explore the function of genotypes, alleles, and haplotypes of two SNPs within the programmed cell death protein 1 (PDCD1) gene at PD1.3 G/A and PD1.5 C/T on susceptibility to COVID-19 in an Iranian population. The secondary objective was to evaluate the effects of these SNPs on the outcome of the disease. We got blood samples from COVID-19 patients (n = 195) and healthy subjects (n = 500) for genotypic determination of PD1.3 G/A (rs11568821) and PD1.5 C/T (rs2227981) SNPs, using the polymerase chain reaction-restriction fragment length polymorphism method, and constructed four haplotypes for PDCD1 SNPs. We used Pearson's chi-squared test, Fisher's exact test, and T-test for this study and incorporated effect sizes of odds ratio (OR) and standardized mean difference. The frequency of CT genotype of PD1.5 was meaningfully higher in COVID-19 patients (49.2%) than in healthy subjects (37.4%) (p = 0.005). However, these significant differences were not observed in the frequencies of PD1.3 genotypes between the two groups (p > 0.05). Of all estimated haplotypes for PDCD1, only AT was significantly and largely associated with COVID-19 susceptibility (p = 0.01, OR: 7.79 [95% confidence interval = 1.56-38.79]), however, this finding is inconclusive. In addition, the present study showed that the PD1.3 and PD1.5 SNPs were not associated with the outcome of the disease (p > 0.05). These results may propose that the PD1.5 CT genotype and AT haplotype of PDCD1 indecisively contribute to COVID-19 susceptibility in the Iranian population.

Pharmacogenetics and the treatment of HIV-/HCV-coinfected patients

This review will summarize the role of pharmacogenetics in the natural history of hepatitis C, particularly in patients with HIV/HCV and will take the perspective of pharmacogenetics and its influence on the response to antiviral therapy and the susceptibility to develop adverse effects. This review will also devote a section to host genetics in other clinical situations, such as disease progression and acute HCV infection, which may determine whether treatment of HIV-/HCV-coinfected patients is implemented or deferred.

Efficient nonparametric confidence bands for receiver operating-characteristic curves

Receiver operating-characteristic curve is a popular graphical method frequently used in order to study the diagnostic capacity of continuous (bio)markers. In spite of the existence of a huge number of papers devoted to both theoretical and practical aspects of this topic, the construction of confidence bands has had little impact in the specialized literature. As far as the authors know, in the CRAN there are only three R packages providing receiver operating-characteristic curve confidence regions: plotROC, pROC and fbroc. This work tries to fill this gap studying and proposing a new nonparametric method to build confidence bands for both the standard receiver operating-characteristic curve and its generalization for nonmonotone relationships. The behavior of the proposed procedure is studied via Monte Carlo simulations and the methodology is applied on two real-world biomedical problems. In addition, an R function to compute the proposed and some of the previously existing methodologies is provided as online supplementary material.

Pretreatment Predictors of Response to PegIFN-RBV Therapy in Egyptian Patients with HCV Genotype 4

BACKGROUND

Egypt has the highest prevalence of a difficult to treat chronic hepatitis C virus (HCV), genotype 4. Pretreatment factors could guide individualization of therapy which aids in treatment optimization and interleukin IL28B gene polymorphism has been shown to closely relate to HCV treatment response. Polymorphisms in genes encoding inhibitors of T-cell response, which have role in disease progression as Programmed Cell Death 1 (PD-1), and Cytotoxic T-Lymphocytes Antigen-4 (CTLA-4), could be candidate markers predicting treatment response.

METHODS

This cohort study consisted of 200 chronic HCV genotype 4 infected patients treated with PegIFN α-2a and RBV in 2 hepatology centers. Genotyping of the polymorphisms in the IL28B gene region (rs12979860), PD1.3 (rs11568821) and CTLA-4 (rs231775) was performed on DNA collected from each patient using TaqMan® genotyping assay. Groups were classified according to response into sustained virological responders (SVR), or non-responders (NR). A multivariate logistic regression analysis was used to identify potential markers, host pretreatment clinical and viral predictive factors including viral load, insulin resistance, and alpha fetoprotein (AFP) related to treatment response.

RESULTS

Our results showed that in a multivariate analyses IL28B C/C genotype was the most significant predictor for SVR (OR = 10.86; p<0.0001) followed by AFP (OR = 0.915; p = 0.001) then CTLA-4/G genotypes (OR = 1.948; p = 0.022). However, PD-1.3/A genotypes and platelets count were significantly related to response in univariate analysis only (OR = 1.973; p = 0.023; OR = 1.007; p = 0.009 respectively).

CONCLUSION

IL28B SNP, AFP level, and CTLA-4 SNP could be used in conjunction to predict treatment response in HCV genotype 4 infected Egyptian patients.

Integrative role of vitamin D related and Interleukin-28B genes polymorphism in predicting treatment outcomes of Chronic Hepatitis C

BACKGROUND

Improving prediction of treatment outcomes in chronic hepatitis C (CHC) genotype 4 (G4) is necessary to increase sustained viral response (SVR) rates. Vitamin D related and interferon stimulated genes are good candidates as they are recently crosstalk altering interferon response. Thus single nucleotide polymorphisms (SNPs) within some of these genes and multiple stepwise regression analysis including other independent predictors (IL28B(rs12979860), serum 25OH-vitamin D, serum alfa-fetoprotein (AFP)) were performed on a cohort of 200 Egyptian CHC patients treated with Pegylated interferon-alpha (Peg-IFN) plus ribavirin.

METHODS

SNPs in cytochrome P-450 (CYP2R1)(rs10741657AG), vitamin D receptor (VDR)(rs2228570AG, rs1544410CT), oligoadenylate synthetases-like (OASL)(rs1169279CT) and adenosine deaminases acting on RNA (ADAR)(rs1127309TC) genes were analyzed by real-time PCR.

RESULTS

The carrier state of A allele in VDR rs2228570 and CYP2R1 rs10741657 genes were independently associated with SVR [OR 6.453 & 3.536, p < 0.01 respectively]. Combining carriers of A allele in CYP2R1 and VDR genes with IL28B C/C genotype increased the probability of SVR from 80 % to reach 87.8 %, 93 % and 100 %. No relation was found between VDR rs1544410CT, ADAR rs1127309TC, OASL rs1169279CT polymorphisms and treatment outcome. Combining VDR rs2228570 A/A genotype with IL28B C/C genotype increased the probability of SVR from 82 % to reach 100 % and from 29 % to reach 80 % in C/T+ T/T IL28B genotype in none F4 liver disease patients.

CONCLUSION

Vitamin D related (VDR rs2228570 and CYP2R1 rs10741657) and IL28B rs12979860 genes polymorphisms accurately assure SVR in naïve CHC G4 patients treated with low cost standard therapy.

Interleukin 28B polymorphisms as predictors of sustained virological response in chronic hepatitis C: systematic review and meta-analysis

Polymorphism of interleukin 28B gene represents a powerful outcome predictor for interferon-based regimens in hepatitis C virus infection. However, some studies report conflicting results. The predictive value of interleukin 28B genotype over the outcome interferon-α/ribavirin treatment was thoroughly evaluated and compared with virological predictors of response. Literature revision was performed on PubMed. Pooled odds ratios (ORs) were calculated by fixed- or random-effects models. Heterogeneity and publication bias were also assessed. Sixty-two eligible papers including 20 290 patients were retrieved. Both polymorphisms (rs12979860 and rs8099917) were strongly associated with response (OR=4.09 and 4.00, respectively), however, the association was weaker for subjects infected with viral genotypes 2 and 3 (OR=1.52 and 1.49, respectively). Compared with interleukin 28B genotype, the association with response was lower for baseline viremia (OR=2.15) and higher for rapid virological response (OR=13.86). These results provide a critical evaluation of interleukin 28B genotype as a pharmacogenetic predictor in hepatitis C patients.

Genetic variations of IL-28B and PD-1 are in association with the susceptibility and outcomes of HCV infection in Southeast China

Programmed cell death-1 (PD-1) is an important co-inhibitory molecule involved in the progression of chronic viral infections. To investigate the associations of three single nucleotide polymorphisms (SNPs) (rs10204525, rs2227982 and rs36084323) in PD-1 and a previously well-inquired SNP rs12979860 in IL-28B with the outcomes of hepatitis C virus (HCV) infection in Southeast China, a total of 375 healthy controls, 219 spontaneous resolved HCV patients and 600 chronic HCV patients were enrolled in this study. The generation of HCV F protein and PD-1 expression on T cells was determined. Multivariate logistic regression analysis showed no association of rs12979860 CC genotype with spontaneous clearance of HCV infection in our subjects. The generation of HCV F protein was significantly related to HCV infection chronicity, but no significant relationship was found between HCV F protein and SNPs in PD-1. The rs10204525 TT genotype was associated with an increased risk of HCV infection chronicity in age ⩽56years subgroup (adjusted OR=0.390, P=3.8×10(-4)). The C allele of rs10204525 played protective roles in females infected with HCV (adjusted OR=0.608, P=0.008). A significant higher percentage of PD-1 expression on T cells was observed in rs10204525 TT genotype when compared to CC genotype (P=0.047). Moreover, a significant genotype-genotype interaction between IL-28B rs12979860 CC and PD-1 rs10204525 TC+CC was found to be associated with higher rates of spontaneous clearance (adjusted OR=0.689, P=0.032). The combined effect of rs12979860 and rs10204525 was of great value in predicting the outcomes of HCV infection. These analyses showed the importance of IL-28B and PD-1 polymorphisms and their interactions in the outcomes of HCV infection in Chinese Han population in Southeast China.

The relationship between HLA-G and viral loads in non-responder HCV-infected patients after combined therapy with IFN-α2α and ribavirin

Hepatitis C disease is a virus mediated infection causing major health problem worldwide. Conversions of immune surveillance play an important role in response to virus clearance. Immune modulating molecules such as HLA-G and IL-10 that convert immune response toward Th2 may play a role to inhibit response from combined therapy with IFN-α2α and ribavirin. The objective of this study was to investigate the expression of HLA-G and IL-10 in responder and non-responder HCV positive patients. In this study, characteristics of the virus and 48 responder and non-responder patients in response to the combined therapy with IFN-α2α and ribavirin were analyzed. The expression levels of HLA-G and IL-10 were conducted using real-time PCR. Also, soluble HLA-G in both groups of patients and healthy individuals were determined by enzyme-linked immunosorbent assay. According to the obtained data, HCV 1a was the predominant genotype in responder and non-responder patients. Expression levels of HLA-G and IL-10 in non-responder group was significantly more than responder and control groups (P<0.001). Additionally, expression levels of HLA-G and IL-10 were remarkably higher compared to healthy individuals at the beginning of treatment. Soluble HLA-G in non-responder patients was noticeably increased in comparison to responder patients after treatment (P<0.05). These findings suggest that elevation of HLA-G and IL-10 in HCV infected patients may play an important role in response to combined therapy with IFN-α2α and ribavirin.

Diversity of killer cell immunoglobulin-like receptor (KIR) genotypes and KIR2DL2/3 variants in HCV treatment outcome

The aim of this study was to analyse the distribution of KIR haplotypes and the KIR2DL2/3 alleles in chronic HCV-infected patients in order to establish the influence on the response to pegylated interferon plus ribavirin classical treatment. The alleles study of previously associated KIR2DL2/3 showed that KIR2DL2*001 was more frequent in non-SVR (NSVR) (42.2% vs. 27.5%, p<0.05) and KIR2DL3*001 was associated with sustained viral response (SVR) (41.6% vs. 61.2%, p<0.005). The KIR2DL3*001-HLA-C1 association was also significant (24.5% vs. 45.7%, p<0.001). From the frequencies of KIR obtained, 35 genotypes were assigned on the basis of previous studies. The centromeric A/A genotype was more frequent in SVR (44.1% vs. 34.5%, p<0.005) and the centromeric B/B genotype was found to be significantly more frequent in NSVR (20.9% vs. 11.2%, p<0.001). The logic regression model showed the importance of KIR genes in predicting the response to combined treatment, since the positive predictive value (PPV) was improved (from 55.9% to 75.3%) when the analysis of KIR was included in addition to the IFNL3 rs12979860 polymorphism. The study of KIR receptors may be a powerful tool for predicting the combined treatment response in patients with chronic HCV infection in association with the determination of IFNL3 polymorphism.

Relevance of baseline viral genetic heterogeneity and host factors for treatment outcome prediction in hepatitis C virus 1b-infected patients

BACKGROUND

Only about 50% of patients chronically infected with HCV genotype 1 (HCV-1) respond to treatment with pegylated interferon-alfa and ribavirin (dual therapy), and protease inhibitors have to be administered together with these drugs increasing costs and side-effects. We aimed to develop a predictive model of treatment response based on a combination of baseline clinical and viral parameters.

METHODOLOGY

Seventy-four patients chronically infected with HCV-1b and treated with dual therapy were studied (53 retrospectively -training group-, and 21 prospectively -validation group-). Host and viral-related factors (viral load, and genetic variability in the E1-E2, core and Interferon Sensitivity Determining Region) were assessed. Multivariate discriminant analysis and decision tree analysis were used to develop predictive models on the training group, which were then validated in the validation group.

PRINCIPAL FINDINGS

A multivariate discriminant predictive model was generated including the following variables in decreasing order of significance: the number of viral variants in the E1-E2 region, an amino acid substitution pattern in the viral core region, the IL28B polymorphism, serum GGT and ALT levels, and viral load. Using this model treatment outcome was accurately predicted in the training group (AUROC = 0.9444; 96.3% specificity, 94.7% PPV, 75% sensitivity, 81% NPV), and the accuracy remained high in the validation group (AUROC = 0.8148, 88.9% specificity, 90.0% PPV, 75.0% sensitivity, 72.7% NPV). A second model was obtained by a decision tree analysis and showed a similarly high accuracy in the training group but a worse reproducibility in the validation group (AUROC = 0.9072 vs. 0.7361, respectively).

CONCLUSIONS AND SIGNIFICANCE

The baseline predictive models obtained including both host and viral variables had a high positive predictive value in our population of Spanish HCV-1b treatment naïve patients. Accurately identifying those patients that would respond to the dual therapy could help reducing implementation costs and additional side effects of new treatment regimens.

Meta-analysis: implications of interleukin-28B polymorphisms in spontaneous and treatment-related clearance for patients with hepatitis C

BACKGROUND

Since 2009, several studies have identified single-nucleotide polymorphisms (SNPs) near the gene encoding for interleukin (IL)-28 (IL28B) that are strongly associated with spontaneous and treatment-induced hepatitis C virus (HCV) clearance. Because this large amount of data includes some inconsistencies, we consider assessment of the global estimate for each SNP to be essential.

METHODS

Relevant studies assessing IL28B polymorphisms associated with sustained virologic response (SVR) and spontaneous clearance (SC) were identified from a literature search of PubMed up to 9 July, 2012. Studies were eligible studies if they included patients infected with HCV or HCV/HIV, or assessed any SNP located within or near the IL28B gene, SVR data available under standard treatment, and/or SC data in patients with acute HCV infection. Pooled odds ratios were estimated by fixed or random effects models when appropriate. Variables such as HCV genotype, ethnicity, and type of co-infection were studied.

RESULTS

Of 282 screened studies, 67 were selected for SVR and 10 for SC. In total, 20,163 patients were studied for SVR and 3,554 for SC. For SVR, we found that all SNPs showed strong associations in patients with HCV genotypes 1 and 4, whereas the pooled ORs were almost three times lower for genotypes 2 and 3 (rs12979860 and rs8099917). Regarding ethnicity, the SNP most associated with SVR was rs12979860 in white patients, whereas in East Asians it seemed to be rs8099917. The most studied SNP (rs12979860) showed similar results for patients co-infected with HCV/HIV, as for those infected with HCV only. Finally, rs12979860 and rs8099917 both appeared to be associated with SC.

CONCLUSIONS

IL28B polymorphisms influence both the outcome of interferon treatment and the natural clearance of HCV. However we did not identify a universal predictor SNP, as the best genetic markers differed depending on patient ethnicity, genotype, and type of infection. Nevertheless, our results may be useful for more precise treatment decision-making.

IL28B polymorphisms as a pretreatment predictor of response to HCV treatment

Genome-wide association studies have identified polymorphisms located near the gene encoding IL28B, which turned out to be the best predictor of response to pegylated interferon plus ribavirin for chronic hepatitis C virus (HCV) genotype 1 infection. This association was extended to spontaneous clearance of HCV, suggesting shared mechanisms of treatment and natural control of this virus. In addition to the biologic implications for innate immunity and HCV, a variety of clinical studies have suggested possible translation to a useful genetic test for practitioners. This article reviews the discovery, biology, and potential clinical applications that have stemmed from the seminal observation that IL28B polymorphisms are a main predictor of HCV clearance.

Boceprevir and personalized medicine in hepatitis C virus infection

Boceprevir was the first agent, along with telaprevir, of a novel class of direct-acting antivirals that entered clinical practice for the treatment of chronic hepatitis C. Boceprevir is an antiprotease that directly blocks hepatitis C virus (HCV) replication. Two studies in patients with HCV genotype 1 infection have shown that addition of boceprevir to the standard of care, ie, pegylated interferon-alfa (PEG-IFN-α) and ribavirin, markedly increased the rate of sustained virological response. A sustained virological response was obtained in about 70% of patients who had never been treated, as well as in 69%-75% and 40% of previous relapsers and nonresponders to PEG-IFN-α-ribavirin, respectively. Side effects were observed in almost all treated patients. Anemia, the most frequent adverse event related to administration of boceprevir, occurred in about 50% of patients. The decision to add boceprevir to the standard of care is made on an individual basis, and takes into account the prognosis of the liver disease, the efficacy of therapy, as it could be at best predicted, and the side effects that may arise, taking into account the comorbidities of the patient. Ultimately, the treatment must be accepted by the patient, who should fully understand the benefits and risks. Boceprevir trials were designed with the concept of individualized and response-guided therapy which establishes treatment decisions on how rapidly patients respond to treatment. Individualized therapy for chronic hepatitis C is based on patient and viral characteristics to make the best choice about whether a person will benefit from therapy and to evaluate on-treatment predictors of response to shorten therapy in patients with a rapid response as well as in patients who did not respond sufficiently to expect HCV eradication. This review focuses on the main results obtained so far, their impact on the treatment of patients with chronic hepatitis C, and potential therapeutic perspectives.