IL28B genotype predicts response to chronic hepatitis C triple therapy with telaprevir or boceprevir in treatment naïve and treatment-experienced patients other than prior partial- and null-responders.

Single nucleotide polymorphisms (SNPs) in the IL28B gene were shown to have limited utility in predicting response to telaprevir and boceprevir in treatment of chronic HCV infection in clinical trials. Data outside of the clinical trial setting are lacking. We assessed the value of single and combined IL28B SNPs rs12979860 and rs8099917 genotypes in predicting sustained virological response 12 weeks after cessation of triple therapy (SVR12) with telaprevir or boceprevir in a single-centre cohort of treatment-naïve and treatment-experienced patients with genotype 1 HCV mono-infection (n = 105). The overall SVR12 rate was 65.7%. By unadjusted bivariate logistic regression analysis, rs12979860-CC and rs8099917-TT were significantly associated with SVR12 in the subgroup of patients including all naïve patients and all treatment-experienced patients with the exception of partial- and null-responders to previous HCV therapy. The predictive value of rs12979860-CC was stronger than rs8099917-TT and only rs12979860-CC remained significantly predictive of treatment success when the two variants were assessed by adjusted logistic regression analysis in the whole study cohort. In patients presenting the rs12979860-CC variant, the additional determination of rs8099917 genotype had no value. IL28B rs12979860-CC remained significantly associated with SVR12 also in the multivariate analysis including the other baseline characteristics associated to SVR12 in the bivariate analysis (i.e., female gender, HCV genotype 1b, baseline viral load <800,000 IU/mL, advanced liver fibrosis and prior partial- or null-response to HCV therapy). Our study suggests that testing for the IL28B rs12979860 genotype may still be useful in predicting response to triple therapy with boceprevir and telaprevir in naïve patients and treatment-experienced patients other than partial and null-responders.

Evaluation of sequencing of HCV core/E1, NS5A and NS5B as a genotype predictive tool in comparison with commercial assays targeting 5'UTR.

BACKGROUND: Hepatitis C virus (HCV) genotyping is required for tailoring the dose and duration of antiviral therapy, predicting virological response rates, and selecting future treatment options. OBJECTIVE: To establish whether baseline genotypes, performed by INNO-LiPA Version 1.0 (v1.0), before 2008, were valid for making treatment decisions now or whether genotypic determination should be repeated. Furthermore, to evaluate concordance between Abbott RealTime genotype II assay (RT) and genotyping by sequencing HCV C/E1, NS5A, NS5B. STUDY DESIGN: Genotyping by RT and sequencing was performed on paired historic and current specimens from 50 patients previously baseline genotyped using INNO-LiPA. RESULTS: Of 100 samples from 50 patients, ≥ 2 of HCV genomic target regions yielded a sequence that was suitable for genotyping, with 100% concordance, providing no evidence of recombination events. Genotype and subtype prediction based on RT and sequencing agreed in 62.8% historic and 72.7% current specimens, with a kappa coefficient score of 0.48 and 0.76, respectively. LiPA could not subtype 46% of HCV gt1 infections, and LiPA subgenotype was only in agreement with RT and sequencing in 28.6% cases, where matched baseline and historic specimens were available. Three patients were indeterminate by RT, and five patients with HCV gt1 infections could not be subtyped by RT. However, RT revealed mixed infections in five patients where sequencing detected only single HCV infection at 20% threshold. CONCLUSION: Genotyping by sequencing, exhibited excellent concordance, with moderate to good agreement with RT, and could resolve RT indeterminates and subtype HCV-gt1 infections not possible by LiPA.

The prevalence of occult hepatitis B virus (HBV) infection in a large multi-ethnic haemodialysis cohort.

BACKGROUND: Haemodialysis patients are at increased risk of exposure to blood borne viruses. To reduce transmission in the UK, all haemodialysis patients are regularly screened, and if susceptible to Hepatitis B virus (HBV) infection, vaccinated. METHODS: This retrospective study was undertaken to determine the HBV immune status in a large dialysis cohort and the prevalence of occult HBV infection, defined as the presence of anti-HBcore antibody (anti-HBcAb) and HBV DNA without detectable HB surface antigen (HBsAg). Information on HBV status was retrieved from haemodialysis patients under the care of The Royal Free Hospital, London, UK between 2009-2010. Available sera from 138 of 161 anti-HBcAb positive/HBsAg negative individuals were anonymised and tested for HBV DNA by a real time quantitative PCR. RESULTS: 15 (2%) of 793 patients had chronic HBV infection (HBsAg positive). 161 (20%) were anti-HBcAb positive but HBsAg negative suggesting past infection. 335 (54%) of the remaining 617 patients were considered immune following vaccination (anti-HBsAb > 10 IU/L). Three (2.2%) of the 138 anti-HBcAb positive, HBsAg negative patients had detectable HBV DNA (3, 5 and 9 IU/ml). Standard liver function tests were normal in these patients. CONCLUSIONS: In a large multi-ethnic London haemodialysis cohort, 20% patients had evidence of past HBV infection. Despite this, the prevalence of occult HBV was found to be low and the very low levels of HBV DNA detected are unlikely to pose a nosocomial transmission risk in the presence of robust vaccination and infection control measures.

Telaprevir or boceprevir based therapy for chronic hepatitis C infection: development of resistance-associated variants in treatment failure.

The use of triple-therapy, pegylated-interferon, ribavirin and either of the first generation hepatitis C virus (HCV) protease inhibitors telaprevir or boceprevir, is the new standard of care for treating genotype 1 chronic HCV. Clinical trials have shown response rates of around 70-80%, but there is limited data from the use of this combination outside this setting. Through an expanded access programme, we treated 59 patients, treatment naïve and experienced, with triple therapy. Baseline factors predicting treatment response or failure during triple therapy phase were identified in 58 patients. Thirty seven (63.8%) of 58 patients had undetectable HCV RNA 12weeks after the end of treatment. Genotype 1a (p=0.053), null-response to previous treatment (p=0.034), the rate of viral load decline after 12weeks of previous interferon-based treatment (p=0.033) were all associated with triple-therapy failure. The most common cause of on-treatment failure for telaprevir-based regimens was the development of resistance-associated variants (RAVs) at amino acids 36 and/or 155 of HCV protease (p=0.027) whereas in boceprevir-based regimens mutations at amino acid 54 were significant (p=0.015). SVR12 rates approaching 64% were achieved using triple therapy outside the clinical trial setting, in a patient cohort that included cirrhotics.

Serological cross reactivity to CMV and EBV causes problems in the diagnosis of acute hepatitis E virus infection.

Hepatitis E virus (HEV) infection is an important public health concern as a major cause of enterically-transmitted hepatitis worldwide. The detectable window of viraemia is narrow, and HEV IgM and IgG rise simultaneously in acute infection. Furthermore, previous investigators have shown HEV IgM false positive reactions occur against EBV, CMV and potentially hepatitis A. A retrospective analysis of HEV serology testing was performed at a London tertiary referral hospital over a 3-year period. A thousand four hundred and twenty three serum samples were tested for HEV serology, with 33 samples HEV IgM positive and 28 HEV IgM equivocal. One hundred and eleven samples were HEV IgG positive but IgM negative suggesting past infection. No patients with HEV IgM positivity had false positive reactions against hepatitis A. A high degree of EBV and CMV cross reactivity was noted, with 33.3% and 24.2% of HEV IgM positive samples also testing positive for EBV and CMV IgM, respectively. HEV RNA was detected in four HEV IgM positive samples, indicating true positivity, although three demonstrated cross reactivity against EBV. Only 13.3% of samples with positive HEV IgM were HEV PCR positive, highlighting a low positive predictive value of serology testing. Overall a high level of HEV, EBV and CMV IgM cross reactivity was demonstrated, indicating that serology is unreliable in the diagnosis of acute viral hepatitis. It is concluded that that the diagnosis of viral hepatitis should be based on clinical features, raised transaminases, serology, and confirmatory PCR testing.

Comparative evaluation of the Artus HIV-1 QS-RGQ assay and the Abbott RealTime HIV-1 assay for the quantification of HIV-1 RNA in plasma.

BACKGROUND: The quantitative measurement of HIV-1 RNA levels in plasma ('viral load') is essential in the management of HIV-infected patients. OBJECTIVE: The new Artus HIV-1 QS-RGQ assay ('Artus(HIV)') for HIV-1 RNA quantification in plasma was compared to the Abbott RealTime HIV-1 assay ('RealTime') following automated RNA isolation by the QIAsymphony and Abbott m2000 extractors, respectively. Emphasis was placed on assay performance with diverse HIV-1 subtypes and in patients receiving antiretroviral therapy (ART). STUDY DESIGN: Plasma from 211 patients (105 subtype B, 87 non-B subtypes; 147 on ART) and serial dilutions of the WHO 2nd International HIV-1 RNA Standard (WHO-IS) were tested by the two assays in parallel. Assay relationship and agreement were determined by linear regression, correlation analysis, and Bland-Altman analysis. RESULTS: With 125 specimens quantified by both assays, measurements were linearly associated and strongly correlated. Overall Artus reported higher levels by mean 0.24 (95% confidence interval [CI] 0.16-0.32) log(10) copies/ml (P < 0.0001); 5 samples (subtypes A, B, CRF01, CRF03) fell outside the 95% agreement. Discordant results were obtained with 11 and 13 samples quantified by either ArtusHIV or RealTime alone respectively, at levels generally close to the lower limit of quantification, giving an overall discordance rate of 24/211 (11%). Both assays generally under-quantified the WHO-IS by between 0.1 and 0.4 log(10) copies/ml across seven dilutions. CONCLUSIONS: The ArtusHIV assay offers performance comparable to that of the RealTime assay across a wide range of HIV-1 subtypes and among both treated and untreated patients.

Comparative evaluation of the ExaVir Load version 3 reverse transcriptase assay for measurement of human immunodeficiency virus type 1 plasma load.

In resource-limited settings, the virological monitoring of antiretroviral therapy is limited by high cost and the lack of infrastructure. The Cavidi ExaVir Load assay employs a simple and inexpensive enzyme-linked immunosorbent assay format to measure human immunodeficiency virus (HIV) reverse transcriptase activity, which correlates with plasma RNA load. The version 3 assay has been described as having improved precision and sensitivity. There are limited data on its performance relative to those of current real-time assays. Our objective was to compare HIV type 1 (HIV-1) RNA load measurement in plasma by ExaVir Load version 3 (designated ExaVir), Abbott M2000sp/M2000rt RealTime HIV-1 assay (designated RealTime), and Roche COBAS Ampliprep/COBAS TaqMan HIV-1 version 1 assay (designated TaqMan). Plasma from 119 patients (34 with subtype B infection, 85 with non-subtype B infection [A-H, CRF01, CRF02, CRF06, CRF12, CRF14, and complex]; 48 subjects were treatment experienced, 71 were naive) and serial dilutions of the second international standard (IS) were tested. Assay relationship and agreement were determined by linear regression, correlation analysis, and the Bland-Altman method. The ExaVir assay quantified 77/83 (92.8%) samples with viral loads of >2.3 log10 copies/ml by the molecular assays. Results were linearly associated and strongly correlated with RealTime and TaqMan measurements (R of 0.94 and 0.92, respectively) for both subtype B (R of 0.97 and 0.95, respectively) and non-subtype B (R of 0.93 and 0.91, respectively) samples. Mean differences were 0.28 and 0.18 log10 copies/ml in favor of the two molecular assays; 7/119 (5.9%) and 5/119 (4.2%) samples were outside the 95% level of agreement. ExaVir underquantified the IS by a mean of 0.2 (range, 0.0 to 0.5) log10 copies/ml. The ExaVir assay showed excellent concordance with real-time molecular assays, offering a suitable option for virological monitoring in settings with limited infrastructure.

Travel-associated acquisition of hepatitis C virus infection in patients receiving haemodialysis.

BACKGROUND: It has been proposed that hepatitis C virus (HCV)-infected patients with end-stage renal disease undergoing maintenance haemodialysis may lack HCV antibody (anti-HCV) despite chronic HCV viraemia. This carries important implications for the design of surveillance policies. METHODS: To characterize the prevalence of antibody-negative/RNA-positive HCV infection, patients attending seven haemodialysis units underwent anti-HCV testing using a third-generation assay and HCV RNA testing using real-time PCR. RESULTS: At screening, anti-HCV prevalence was 12/360 (3.3%; 95% CI 1.7-5.8%); 7/12 (58.3%) anti-HCV positive samples were HCV RNA positive. Among anti-HCV-negative samples, 2/348 (0.6%; 95% CI 0.2-2.1%) tested HCV RNA positive (genotype 1a). Retrospective testing of stored sera dated the infections to a period of holiday in the Indian subcontinent. The two infections were unrelated by HCV-NS5B sequencing. Only one of the two newly infected persons showed raised transaminases. Both developed anti-HCV within 8-13 weeks of follow-up. Prospective surveillance of travellers to resource-limited countries returning to the units showed a HCV incidence of 4/153 travel episodes (2.6%; 95% CI 0.7-6.6%) among 131 persons (3.1%; 95% CI 0.8-7.6%). CONCLUSIONS: Among haemodialysis patients in the United Kingdom, antibody-negative/RNA-positive HCV status is associated with newly acquired infection, rather than lack of antibody responses in chronic HCV infection. There is a significant risk of HCV infection associated with travel to resource-limited countries. Given that transaminase levels may be normal, HCV RNA testing is recommended in patients re-entering a dialysis unit following haemodialysis in settings where suboptimal infection control policies pose a risk of exposure to blood-borne viruses.