Norma Rallón

Association of a single nucleotide polymorphism near the interleukin-28B gene with response to hepatitis C therapy in HIV/hepatitis C virus-coinfected patients

Background:Given that peginterferon–ribavirin treatment is poorly tolerated, there is interest in the identification of predictors of response, particularly in HIV/hepatitis C virus (HCV)-coinfected patients that respond less than HCV-monoinfected individuals. A single nucleotide polymorphism (SNP) near the IL28B gene (rs12979860) has been shown to predict treatment response in HCV-monoinfected patients carrying genotype 1. Information is lacking for HIV/HCV-coinfected individuals and/or other HCV genotypes. Methods:From 650 HIV/HCV-coinfected patients, we identified those who had completed a course of peginterferon–ribavirin therapy with a validated outcome and available repository DNA. The rs12979860 SNP was examined in a blinded fashion. Results:A total of 164 patients were included in the final IL28B genotyping analysis, 90 (55%) of whom achieved sustained virological response (SVR). HCV genotype distribution was as follows: HCV-1 58%, HCV-3 31% and HCV-4 11%. Overall, the SVR rate was higher in patients with CC than in those CT/TT genotypes: 56 of 75 (75%) versus 34 of 89 (38%) (P < 0.0001). The effect of the SNP was seen in HCV genotypes 1 and 4 but not in HCV genotype 3 carriers. In the multivariable analysis (odds ratio; 95% confidence interval; P value), the rs12979860 CC genotype was a strong predictor of SVR (3.7; 1.6–8.5; 0.002), independent of HCV genotype 3 (8.0; 3.1–21.0; <0.001), serum HCV-RNA less than 600 000 IU/ml (11.9; 3.8–37.4; <0.001) and lack of advanced liver fibrosis (3.5; 1.4–8.9; 0.009). Conclusion:The rs12979860 SNP located near the IL28B gene is associated with HCV treatment response in HIV-infected patients with chronic hepatitis C due to genotypes 1 or 4. Thus, IL28B genotyping should be considered as part of the treatment decision algorithm in this difficult-to-treat population.

Long-term non-progressors display a greater number of Th17 cells than HIV-infected typical progressors

Interleukin 17 (IL17) secreting T (Th17) cells play a protective role against bacterial infections at mucosal surfaces. Recent reports show Th17 cells are depleted in the gut associated lymphoid tissue of HIV+ patients, but their role in HIV disease progression is not well understood. Expression of the IL17 receptor (IL17R) and the production of IL17 were compared between two groups of HIV patients with different disease progression (long-term-nonprogressors, LTNP and typical-progressors, TP). IL17R expression was similar in LTNP and TP, whereas Th17 cell number was greater in LTNP than TP (p=0.015). An inverse correlation between the plasma HIV-RNA and both IL17R expression and Th17 cell number was found (p=0.001 and p=0.002, respectively). The increased number of Th17 cells in LTNP could lead to a more preserved immune response against bacterial infections. As a result, lower microbial translocation could explain the reduced immune activation and slower disease progression seen in LTNP.

Modeling the Probability of Sustained Virological Response to Therapy with Pegylated Interferon plus Ribavirin in Patients Coinfected with Hepatitis C Virus and HIV

BACKGROUND A single-nucleotide polymorphism (SNP) near the IL28B gene (rs12979860) strongly predicts sustained virological response to pegylated interferon plus ribavirin (pegIFN-RBV) treatment for chronic hepatitis C virus (HCV) infection. Given that therapy is poorly tolerated and rates of response are lower in patients coinfected with HCV and human immunodeficiency virus (HIV), the recognition of predictors of response is a high priority in this population. METHODS A baseline noninvasive index was derived on the basis of the probability of achieving sustained virological response in a group of 159 HIV-HCV-coinfected patients treated at one clinic in Spain. The index was then validated using data from a separate cohort of 86 coinfected individuals. Only individuals who had completed a course of pegIFN-RBV therapy and had validated outcomes were considered. RESULTS The final score included 4 variables: 2 host-related variables (IL28B SNP rs12979860 and liver stiffness) and 2 HCV-related variables (genotype and viral load). The area under the receiver operating characteristic curve was 0.89 in the derivation group and 0.85 in the validation group. CONCLUSIONS The probability of achieving sustained virological response with pegIFN-RBV therapy in HIV-HCV-coinfected patients can be reliably estimated prior to initiation of therapy using an index that includes 4 noninvasive parameters.

Influence of Interleukin-28B Single-Nucleotide Polymorphisms on Progression to Liver Cirrhosis in Human Immunodeficiency Virus–Hepatitis C Virus–Coinfected Patients Receiving Antiretroviral Therapy

BACKGROUND Single-nucleotide polymorphisms (SNPs) near the IL28B gene have recently been associated with spontaneous hepatitis C virus (HCV) clearance and response to interferon-based therapies in patients with chronic hepatitis C. Because human immunodeficiency virus (HIV) coinfection appears to accelerate HCV-related liver fibrosis progression, any influence of IL28B SNP on the risk of developing cirrhosis might be more easily recognized in the coinfected population. METHODS All HIV-HCV-coinfected patients who underwent hepatic elastography before initiating a course of pegylated interferon plus ribavirin therapy at 2 Spanish clinics were retrospectively identified. Liver cirrhosis was defined as >14.5 kPa by transient elastography. The IL28B rs12979860 SNP was examined in a blinded fashion. RESULTS A total of 304 HIV-HCV-coinfected individuals were analyzed (mean age, 43 years; 80% were male; and 85% were receiving antiretroviral therapy), of whom 18% had cirrhosis. IL28B genotype distribution was as follows: CC, 46%; CT, 43%; and TT, 11%. Cirrhosis was more frequent in CC than CT/TT carriers (24% vs 13%; P = .01). Logistic regression analysis revealed that older age (odds ratio [OR], 1.05; 95% confidence interval [CI], 0.99-1.12]; P = .08), past alcohol abuse (OR, 1.97; 95% CI, 0.95-4.06; P = .07), and CC IL28B genotype (OR, 2.32; 95% CI, 1.22-4.41; P = .01) were predictors of cirrhosis. Interestingly, mean (SD) alanine aminotransferase (ALT) levels were greater (90 ± 53 vs 71 ± 33 IU/L;, P = .01) in IL28B CC than CT/TT carriers during the prior 4.8 ± 3.8 years. CONCLUSIONS The IL28B rs12979860 CC genotype is associated with a higher prevalence of cirrhosis in HIV-HCV-coinfected patients than CT/TT genotypes, suggesting that IL28B CC carriers may experience a more rapid progression of HCV-related liver fibrosis, perhaps as result of increased liver inflammation. Thus, access to HCV treatment is of utmost importance in IL28B CC carriers, in whom treatment response is better and in whom progression to cirrhosis might occur more rapidly.

IL28B gene polymorphisms and viral kinetics in HIV/hepatitis C virus-coinfected patients treated with pegylated interferon and ribavirin

Background:A single nucleotide polymorphism (SNP) upstream of the IL28B gene (rs12979860) predicts sustained virological response (SVR) to peginterferon–ribavirin therapy in chronic hepatitis C patients. There is scarce information regarding the influence of this IL28B SNP on early viral kinetics during therapy, particularly in patients coinfected with HIV, in whom treatment response is lower than in hepatitis C virus (HCV)-monoinfected patients. Methods:We selected 196 HIV/HCV-coinfected individuals who had completed a course of peginterferon–ribavirin therapy, and a validated outcome for SVR. Association of IL28B SNPs with rapid, early and end-of-treatment virological responses [rapid virological response (RVR), early virological response (EVR) and end of treatment virological response, respectively] was assessed in univariate and multivariate analyses. Results:Rate of SVR in the study population was 54%. Frequency of the IL28B CC genotype was 44%. The distribution of HCV genotypes was as follows: HCV-1 57%, HCV-2 1%, HCV-3 30% and HCV-4 12%. Compared to CT/TT, the CC genotype was associated with significantly higher rates of all on-treatment viral outcomes, after adjusting for other predictors of viral response as serum HCV-RNA, HCV genotype and liver fibrosis staging. IL28B CC genotype kept its predictive power of SVR in patients who did not achieve RVR or cEVR. The association between IL28B SNP and viral kinetics and treatment outcomes was significant only for HCV genotypes 1 and 4. Conclusion:IL28B CC genotype is a strong predictor of virological response to therapy in HIV/HCV-coinfected patients. This effect is mediated by an increase in viral clearance during the first 12 weeks of treatment and is mainly seen in patients infected with HCV genotypes 1 and 4.

Prediction of response to pegylated interferon plus ribavirin in HIV/hepatitis C virus (HCV)-coinfected patients using HCV genotype, IL28B variations, and HCV-RNA load.

BACKGROUND & AIMS This study aimed at developing a predictive algorithm based on interleukin 28B (IL28B) genotype, hepatitis C virus (HCV) genotype, and plasma HCV-RNA load, which could accurately allow us to define the probability of response to pegylated interferon (Peg-IFN) plus ribavirin (RBV) therapy in HIV/HCV-coinfected patients. METHODS Five hundred and twenty-one treatment-naive HIV-infected patients, who initiated HCV therapy with Peg-IFN/RBV, were analysed in an on-treatment basis. Patients were categorized as unlikely responders, uncertain responders, and anticipated responders (<20%, 20-60%, and >60% probability to achieve SVR, respectively). RESULTS HCV genotype, baseline HCV-RNA load, and IL28B genotype were confirmed as independent predictors of SVR in a logistic regression analysis. A stepwise algorithm based on these three variables was created based on 321 patients and evaluated in the remaining 200 patients. Unlikely responders included patients with genotype 1 or 4, HCV-RNA load ≥600,000IU/ml, and rs12979860 non-CC (rate of SVR: 17.3%). Anticipated responders were those with HCV genotype 2-3, patients harboring HCV genotype 4 and IL28B CC, as well as those who simultaneously bore HCV genotype 1, HCV-RNA load <600,000IU/ml, and IL28B CC (rate of SVR 74.1%, 77.8%, and 64.4%, respectively). The area under the receiver operating characteristic curve of the model was 0.77 (0.733-0.814). CONCLUSIONS The combined use of IL28B genotype, HCV genotype, and HCV-RNA load enables to easily identify patients with a high and very low likelihood of SVR. HCV therapy could be deferred in the latter patients, until more effective options are available, at least if they do not show advanced liver fibrosis.

Low-Level Exposure to HIV Induces Virus-Specific T Cell Responses and Immune Activation in Exposed HIV-Seronegative Individuals

HIV-specific T cells response and T cell activation are frequently seen in exposed seronegative individuals (ESN). In this study, we report HIV-specific response and level of T cell activation in ESN partners of HIV-infected patients presenting low or undetectable levels of HIV-RNA. We evaluated 24 HIV-serodiscordant couples. ESN were classified into three categories of exposure to HIV (very low, low, and moderate-high), considering levels of HIV-RNA in their infected partner and frequency of sexual high-risk practices within the last 12 mo. HIV-specific T cell responses and activation levels in T cell subsets were evaluated by flow cytometry. We reported that 54% of ESN had detectable HIV-specific T cells response, being the highest prevalence seen in the low exposure group (64%). Several T cell subsets were significantly increased in ESN when compared with controls: CD4+CD38+ (p = 0.006), CD4+HLA-DR−CD38+ (p = 0.02), CD4+CD45RA+CD27+HLA-DR−CD38+ (p = 0.002), CD8+CD45RA+CD27+CD38−HLA-DR+ (p = 0.02), and CD8+CD45RA+CD27−CD38+HLA-DR+ (p = 0.03). Activation of CD8+ T cells was increased in ESN with detectable HIV T cell responses compared with ESN lacking these responses (p = 0.04). Taken together, these results suggest that persistent but low sexual HIV exposure is able to induce virus-specific T cells response and immune activation in a high proportion of ESN, suggesting that virus exposure may occur even in conditions of maximal viral suppression in the HIV-infected partner.

Pharmacogenetics of hepatitis C

Recent discoveries have highlighted the influence of host genomics on hepatitis C virus (HCV) infection outcomes. As a result, our views on hepatitis C pathogenesis and therapeutic approaches have been transformed. The recognition of the impact of single-nucleotide polymorphisms (SNPs) of the genes interleukin 28B (IL28B), inosine triphosphatase (ITPA) and low-density lipoprotein cholesterol receptor (LDLR) may lead to refinements in the pharmacogenomic prediction of antiviral response and drug-related toxicities and favour the discovery of new therapeutic targets for hepatitis C. Although the relevance of host genetics may be less in the setting of very potent new direct-acting antivirals (DAAs), genetic markers may continue to aid decision making regarding the length of therapy. Moreover, in several populations, such as HIV/HCV-coinfected patients, current therapy with peginterferon-α/ribavirin will continue in use for most patients, and thus host factors will retain their predictive value for treatment outcomes for a while.

Variants in the ITPA Gene Protect Against Ribavirin-Induced Hemolytic Anemia in HIV/HCV-Coinfected Patients With All HCV Genotypes

BACKGROUND A recent genome-wide association study reported a strong association with a single-nucleotide polymorphism (SNP) in the inosine triphosphate (ITPA) gene and hemolytic anemia in patients infected with hepatitis C virus (HCV) receiving pegylated interferon and ribavirin. We investigate these polymorphisms in a cohort of human immunodeficiency virus (HIV)/HCV-coinfected patients. METHODS DNA was available for 161 patients with validated outcomes. We analyzed the association between the variants and week 4 hemoglobin reduction. Anemia over the course of therapy, ribavirin (RBV) dose reduction, serum RBV level, and rapid virological response (RVR) and sustained virological response (SVR) were also investigated. Using a candidate gene approach, ITPA variants rs1127354 and rs7270101 were tested using the ABI TaqMan kit. Multivariable models were used to identify predictors of anemia. RESULTS A significant minority (33%) of patients were predicted to have reduced ITPase activity. The minor allele of each variant was associated with protection against week 4 anemia. In multivariable models only the genetic variants, creatinine, and zidovudine exposure remained significant. ITPase deficiency was not associated with RBV-dose reduction, RVR, or SVR. CONCLUSIONS This study confirms that polymorphisms in the ITPA gene are associated with protection from RBV-induced anemia in HIV/HCV-coinfected patients but not improved clinical outcomes.

Interleukin-28b gene polymorphisms do not influence the susceptibility to Hiv-infection or Cd4 cell decline

The critical role of interleukin-28B (IL28B)/interferon-λ3 (IFN-λ3) polymorphisms on the susceptibility to hepatitis C virus infection and the response to peginterferon–ribavirin therapy has encouraged exploration of similar effects on other viruses. Given that IFN-λ mediates anti-HIV-1 activity, the protective role of IL28B polymorphisms was examined in 29 seronegative individuals at risk for HIV-infection and in 68 HIV-positive carriers with and without rapid progression of immunodeficiency. No protective role of IL28B polymorphism was found examining both HIV-disease progression and HIV-protection.