Real-World Safety, Effectiveness, and Patient-Reported Outcomes in Patients with Chronic Hepatitis C Virus Infection Treated with Glecaprevir/Pibrentasvir: Updated Data from the German Hepatitis C-Registry (DHC-R).

Using data from the German Hepatitis C-Registry (Deutsche Hepatitis C-Register, DHC-R), we report the real-world safety and effectiveness of glecaprevir/pibrentasvir (GLE/PIB) treatment and its impact on patient-reported outcomes (PROs) in underserved populations who are not typically included in clinical trials, yet who will be crucial for achieving hepatitis C virus (HCV) elimination. The DHC-R is an ongoing, non-interventional, multicenter, prospective, observational cohort study on patients treated for chronic HCV infection in Germany. The data cutoff was 17 January 2021. The primary effectiveness endpoint was sustained virologic response at post-treatment Week 12 (SVR12). Safety outcomes were assessed in all patients receiving GLE/PIB. PROs were assessed using the SF-36 survey. Of 2354 patients, 1964 had valid SVR12 data (intention-to-treat analysis). Of these, 1905 (97.0%) achieved SVR12 with rates similar across the comorbidities analyzed, except for people who actively use drugs (PWUD (active)) (86.4%). Excluding those who discontinued treatment and did not achieve SVR12, or were reinfected with HCV, the rate was 99.3%, with similar results regardless of comorbidity. PWUD (active) and those with psychiatric disorders had the most meaningful improvements in PROs. Adverse events (AEs) occurred in 631/2354 patients (26.8%), and serious AEs in 44 patients (1.9%). GLE/PIB was highly effective and well tolerated in this real-world study of patient groups key to HCV elimination.

Hepatitis C therapy with grazoprevir/elbasvir and glecaprevir/pibrentasvir in patients with advanced chronic kidney disease: data from the German Hepatitis C-Registry (DHC-R).

OBJECTIVES: Grazoprevir/elbasvir and glecaprevir/pibrentasvir (G/P) are the two preferred treatment options for patients with chronic hepatitis C virus (HCV) infection and a glomerular filtration rate (GFR) <30 mL/min. Both therapies have been separately analyzed in different real-life cohorts; however, a direct comparison has not been performed so far. We, therefore, analyzed safety and effectiveness of both regimens in a concerted real-life population. METHODS: The Germany Hepatitis C-Registry is a prospective national real-world registry. The analysis is based on 2773 patients with documented GFR at baseline treated with grazoprevir/elbasvir (N = 1041), grazoprevir/elbasvir + ribavirin (N = 53) and glecaprevir/pibrentasvir (N = 1679). RESULTS: A total of 93 patients with GFR <30 mL/min were treated with grazoprevir/elbasvir (N = 56), grazoprevir/elbasvir + ribavirin (N = 4), and glecaprevir/pibrentasvir (N = 33). They suffered significantly more frequent from diabetes mellitus, hypertension, and coronary heart disease than individuals with GFR >30 mL/min and showed the following baseline characteristics: 20.4, 55.9, 3.2, 12.9, and 5.3% were infected with HCV-genotypes 1a, 1b, 2, 3, and 4; 12.9% suffered from liver cirrhosis; 80.1% were treatment-naïve. Baseline characteristics except distribution of HCV-genotype 1b (n = 43/52 treated with grazoprevir/elbasvir) and sustained virologic response rates (SVR12) did not differ significantly between glecaprevir/pibrentasvir (SVR12: 100%) and grazoprevir/elbasvir (SVR12: 97.9%).Fatigue, headache, abdominal discomfort, and arthralgia were the most frequently reported adverse events without a statistical difference between grazoprevir/elbasvir and glecaprevir/pibrentasvir. CONCLUSION: In patients with chronic hepatitis C and a baseline GFR ≤30 mL/min grazoprevir/elbasvir and glecaprevir/pibrentasvir show an equally favorable safety profile and antiviral efficacy and can both be recommended for real-life use.

Glecaprevir/pibrentasvir for 8 weeks in patients with compensated cirrhosis: Safety and effectiveness data from the German Hepatitis C-Registry.

Glecaprevir/pibrentasvir, a pangenotypic, direct-acting antiviral combination approved for chronic hepatitis C virus treatment, has limited real-world evidence supporting 8-week therapy in compensated cirrhosis. We investigated effectiveness and safety of 187 hepatitis C virus-infected, treatment-naïve, patients with compensated cirrhosis receiving 8-week glecaprevir/pibrentasvir therapy in the German Hepatitis C-Registry between 2 August 2017 and 1 January 2020. Sustained virologic response was 98.4% (127/129) in the per-protocol analysis (excluding patients lost to follow-up or who discontinued treatment due to compliance) and was 85.8% (127/148) in patients with data available in an intention-to-treat analysis. Nineteen patients were lost to follow-up; nine genotype 3 patients, nine nongenotype 3 patients and one mixed genotype patient. One patient relapsed, and one died, unrelated to treatment. Adverse events (>5%) were fatigue and headache. Two serious adverse events occurred; no adverse events resulted in drug discontinuation. An 8-week glecaprevir/pibrentasvir therapy was effective and well-tolerated in this real-world analysis.

Only partial improvement in health-related quality of life after treatment of chronic hepatitis C virus infection with direct acting antivirals in a real-world setting-results from the German Hepatitis C-Registry (DHC-R).

Improvement of health-related quality of life (HRQoL) is frequently reported as a benefit when treating hepatitis C virus infection (HCV) with direct acting antivirals (DAA). As most of the available data were obtained from clinical trials, limited generalizability to the real-world population might exist. This study aimed to investigate the impact of DAA therapy on changes in HRQoL in a real-world setting. HRQoL of 1180 participants of the German Hepatitis C-Registry was assessed by Short-Form 36 (SF-36) questionnaires. Scores at post-treatment weeks 12-24 (FU12/24) were compared to baseline (BL). Changes of ≥2.5 in mental and physical component summary scores (MCS and PCS) were defined as a minimal clinical important difference (MCID). Potential predictors of HRQoL changes were analysed. Overall, a statistically significant increase in HRQoL after DAA therapy was observed, that was robust among various subgroups. However, roughly half of all patients failed to achieve a clinically important improvement in MCS and PCS. Low MCS (p < .001, OR = 0.925) and PCS (p < .001, OR = 0.899) BL levels were identified as predictors for achieving a clinically important improvement. In contrast, presence of fatigue (p = .023, OR = 1.518), increased GPT levels (p = .005, OR = 0.626) and RBV containing therapy regimens (p = .001, OR = 1.692) were associated with a clinically important decline in HRQoL after DAA therapy. In conclusion, DAA treatment is associated with an overall increase of HRQoL in HCV-infected patients. Nevertheless, roughly half of the patients fail to achieve a clinically important improvement. Especially patients with a low HRQoL seem to benefit most from the modern therapeutic options.

Real-World Clinical Management of Patients with Primary Biliary Cholangitis-A Retrospective Multicenter Study from Germany.

BACKGROUND: Clinical practice guidelines for patients with primary biliary cholangitis (PBC) have been recently revised and implemented for well-established response criteria to standard first-line ursodeoxycholic acid (UDCA) therapy at 12 months after treatment initiation for the early identification of high-risk patients with inadequate treatment responses who may require treatment modification. However, there are only very limited data concerning the real-world clinical management of patients with PBC in Germany. OBJECTIVE: The aim of this retrospective multicenter study was to evaluate response rates to standard first-line UDCA therapy and subsequent Second-line treatment regimens in a large cohort of well-characterized patients with PBC from 10 independent hepatological referral centers in Germany prior to the introduction of obeticholic acid as a licensed second-line treatment option. METHODS: Diagnostic confirmation of PBC, standard first-line UDCA treatment regimens and response rates at 12 months according to Paris-I, Paris-II, and Barcelona criteria, the follow-up cut-off alkaline phosphatase (ALP) ≤ 1.67 × upper limit of normal (ULN) and the normalization of bilirubin (bilirubin ≤ 1 × ULN) were retrospectively examined between June 1986 and March 2017. The management and hitherto applied second-line treatment regimens in patients with an inadequate response to UDCA and subsequent response rates at 12 months were also evaluated. RESULTS: Overall, 480 PBC patients were included in this study. The median UDCA dosage was 13.2 mg UDCA/kg bodyweight (BW)/d. Adequate UDCA treatment response rates according to Paris-I, Paris-II, and Barcelona criteria were observed in 91, 71.3, and 61.3% of patients, respectively. In 83.8% of patients, ALP ≤ 1.67 × ULN were achieved. A total of 116 patients (24.2%) showed an inadequate response to UDCA according to at least one criterion. The diverse second-line treatment regimens applied led to significantly higher response rates according to Paris-II (35 vs. 60%, p = 0.005), Barcelona (13 vs. 34%, p = 0.0005), ALP ≤ 1.67 × ULN and bilirubin ≤ 1 × ULN (52.1 vs. 75%, p = 0.002). The addition of bezafibrates appeared to induce the strongest beneficial effect in this cohort (Paris II: 24 vs. 74%, p = 0.004; Barcelona: 50 vs. 84%, p = 0.046; ALP < 1.67 × ULN and bilirubin ≤ 1 × ULN: 33 vs. 86%, p = 0.001). CONCLUSION: Our large retrospective multicenter study confirms high response rates following UDCA first-line standard treatment in patients with PBC and highlights the need for close monitoring and early treatment modification in high-risk patients with an insufficient response to UDCA since early treatment modification significantly increases subsequent response rates of these patients.

Glecaprevir/pibrentasvir is safe and effective in hepatitis C patients with cirrhosis: Real-world data from the German Hepatitis C-Registry.

Glecaprevir/pibrentasvir is a pangenotypic direct-acting antiviral regimen approved for treating chronic hepatitis C virus. Real-world use of protease-inhibitor-containing regimens requires further evaluation in patients with cirrhosis. We evaluated the real-world safety and effectiveness of glecaprevir/pibrentasvir in patients with cirrhosis from the German Hepatitis C-Registry who initiated treatment between 2 August 2017 and 30 June 2019. Overall, 131 patients received 12-week (on-label) treatment and 51 received 8-week (off-label) treatment. No patient discontinued treatment due to adverse events. Four patients had serious adverse events; none were considered related to glecaprevir/pibrentasvir. Two patients had total bilirubin > 5 × upper limit of normal (ULN) during treatment. Three patients had alanine aminotransferase and three patients had aspartate aminotransferase > 3 × ULN. Rates of sustained virologic response were 100% (86/86) for 86 patients with available data. Glecaprevir/pibrentasvir treatment was well-tolerated and highly effective in patients with chronic hepatitis C and cirrhosis in real-world practice.

Multiscale dynamic modeling and simulation of a biorefinery.

A biorefinery comprises a variety of process steps to synthesize products from sustainable natural resources. Dynamic plant-wide simulation enhances the process understanding, leads to improved cost efficiency and enables model-based operation and control. It is thereby important for an increased competitiveness to conventional processes. To this end, we developed a Modelica library with replaceable building blocks that allow dynamic modeling of an entire biorefinery. For the microbial conversion step, we built on the dynamic flux balance analysis (DFBA) approach to formulate process models for the simulation of cellular metabolism under changing environmental conditions. The resulting system of differential-algebraic equations with embedded optimization criteria (DAEO) is solved by a tailor-made toolbox. In summary, our modeling framework comprises three major pillars: A Modelica library of dynamic unit operations, an easy-to-use interface to formulate DFBA process models and a DAEO toolbox that allows simulation with standard environments based on the Modelica modeling language. A biorefinery model for dynamic simulation of the OrganoCat pretreatment process and microbial conversion of the resulting feedstock by Corynebacterium glutamicum serves as case study to demonstrate its practical relevance.

Real-world effectiveness and safety of glecaprevir/pibrentasvir for the treatment of chronic hepatitis C infection: data from the German Hepatitis C-Registry.

BACKGROUND: Glecaprevir/pibrentasvir is a pangenotypic direct-acting antiviral regimen approved for treating adults chronically infected with hepatitis C virus (HCV). There are limited real-world data on glecaprevir/pibrentasvir to date. AIM: To evaluate the effectiveness and safety of glecaprevir/pibrentasvir under real-world conditions in the German Hepatitis C-Registry (DHC-R). METHODS: The DHC-R is an ongoing, non-interventional, multicentre, prospective, observational cohort study that monitors patients with chronic HCV infection. Data were collected from patients who initiated glecaprevir/pibrentasvir and completed a screening visit on or after 2 August 2017. The primary effectiveness endpoint was sustained virological response at post-treatment Week 12 (SVR12). Safety and tolerability were also assessed. RESULTS: As of 15 July 2018, 586 patients received glecaprevir/pibrentasvir and had documented SVR12 data, treatment discontinuation, loss to follow-up or HCV reinfection. Five hundred and fifty-two patients (94%) received on-label treatment. At baseline, most on-label patients were infected with HCV genotype 1 (53%) or 3 (33%), HCV treatment-naïve (90%), without cirrhosis (94%), and treated for 8 weeks (93%). Five hundred and thirty-four patients (96.7%) achieved SVR12 (intention-to-treat [ITT] analysis). By modified ITT analysis (excluding patients who discontinued and did not achieve SVR12 or patients lost to follow-up), the SVR12 rate was 99.4% (n/N = 534/537). There was one documented virological failure (relapse) and two documented HCV reinfections. One hundred and forty-two (26%) adverse events (AEs) and 9 (2%) serious AEs occurred; 2 (<1%) AEs led to treatment discontinuation. All patients treated off-label (N = 34) achieved SVR12. CONCLUSION: Glecaprevir/pibrentasvir was highly effective and well tolerated under real-world conditions. Clinical trial number: DRKS00009717 (German Clinical Trials Register, DRKS).

GPU-Accelerated Adjoint Algorithmic Differentiation.

Many scientific problems such as classifier training or medical image reconstruction can be expressed as minimization of differentiable real-valued cost functions and solved with iterative gradient-based methods. Adjoint algorithmic differentiation (AAD) enables automated computation of gradients of such cost functions implemented as computer programs. To backpropagate adjoint derivatives, excessive memory is potentially required to store the intermediate partial derivatives on a dedicated data structure, referred to as the "tape". Parallelization is difficult because threads need to synchronize their accesses during taping and backpropagation. This situation is aggravated for many-core architectures, such as Graphics Processing Units (GPUs), because of the large number of light-weight threads and the limited memory size in general as well as per thread. We show how these limitations can be mediated if the cost function is expressed using GPU-accelerated vector and matrix operations which are recognized as intrinsic functions by our AAD software. We compare this approach with naive and vectorized implementations for CPUs. We use four increasingly complex cost functions to evaluate the performance with respect to memory consumption and gradient computation times. Using vectorization, CPU and GPU memory consumption could be substantially reduced compared to the naive reference implementation, in some cases even by an order of complexity. The vectorization allowed usage of optimized parallel libraries during forward and reverse passes which resulted in high speedups for the vectorized CPU version compared to the naive reference implementation. The GPU version achieved an additional speedup of 7.5 ± 4.4, showing that the processing power of GPUs can be utilized for AAD using this concept. Furthermore, we show how this software can be systematically extended for more complex problems such as nonlinear absorption reconstruction for fluorescence-mediated tomography.

Performance and Value of IFN-Lambda3 and IFN-Lambda4 Genotyping in Patients with Chronic Hepatitis C (CHC) Genotype 2/3 in a Real World Setting.

BACKGROUND: SNPs near the interferon lambda (IFNL) 3 gene are predictors for sustained virological response (SVR) in patients with chronic hepatitis C genotype (GT) 1. In addition, a dinucleotide frame shift in ss469415590 was described, which generates IFNL4. In this study, we compared the role of IFNL4 variants with IFNL3-(rs12979860) and IFNL3-(rs8099917) on response to pegylated (PEG)-IFN and Ribavirin (RBV) in patients with chronic hepatitis C GT2/3. METHODS: We recruited 1006 patients with chronic hepatitis C and GT2/3 in a large German registry. A treatment with PEG-IFN and Ribavirin was started by 959 patients. We performed genotyping of IFNL3 (rs12979860, n = 726; rs8099917, n = 687) and of IFNL4 (ss469415590; n = 631). RESULTS: Both preferable IFNL3 genotypes were associated with RVR (both p<0.0001) rather than with SVR (rs12979860: p = 0.251; rs8099917: p = 0.447). Only RVR was linked to SVR in univariate and multivariate analyzes (both p<0.001). Concordance of genotyping in patients with available serum samples and EDTA blood samples (n = 259) was more than 96% for both IFNL3 SNPs. IFNL3-(rs12979860) correlated with IFNL4: 99.2% of patients with IFNL3-(rs12979860)-CC were IFNL4-(ss469415590)-TT/TT. IFNL3-(rs12979860)-CT was linked with IFNL4-(ss469415590)-TT/ΔG (98.0%) and IFNL3-(rs12979860)-TT was associated with IFNL4-(ss469415590)-ΔG/ΔG (97.6%). CONCLUSION: IFNL3 genotyping from serum was highly efficient and can be used as an alternative if EDTA whole blood is not available. In Caucasian GT2/3 patients genotyping for INFL4-(ss469415590) does not lead to additional information for the decision-making process. Importantly, IFNL3 SNPs were not associated with SVR but with RVR. Even in the era of new direct acting antiviral (DAA) therapies, IFNL3 testing may therefore still be considered for naïve GT2/3 patients to decide if dual Peg-IFN/RBV therapy is an option in resource limited regions.

Treatment Extension of Pegylated Interferon Alpha and Ribavirin Does Not Improve SVR in Patients with Genotypes 2/3 without Rapid Virological Response (OPTEX Trial): A Prospective, Randomized, Two-Arm, Multicentre Phase IV Clinical Trial.

UNLABELLED: Although sofosbuvir has been approved for patients with genotypes 2/3 (G2/3), many parts of the world still consider pegylated Interferon alpha (P) and ribavirin (R) as standard of care for G2/3. Patients with rapid virological response (RVR) show response rates >80%. However, SVR (sustained virological response) in non-RVR patients is not satisfactory. Longer treatment duration may be required but evidence from prospective trials are lacking. A total of 1006 chronic HCV genotype 2/3 patients treated with P/R were recruited into a German HepNet multicenter screening registry. Of those, only 226 patients were still HCV RNA positive at week 4 (non-RVR). Non-RVR patients with ongoing response after 24 weeks P-2b/R qualified for OPTEX, a randomized trial investigating treatment extension of additional 24 weeks (total 48 weeks, Group A) or additional 12 weeks (total 36 weeks, group B) of 1.5 µg/kg P-2b and 800-1400 mg R. Due to the low number of patients without RVR, the number of 150 anticipated study patients was not met and only 99 non-RVR patients (n=50 Group A, n=49 Group B) could be enrolled into the OPTEX trial. Baseline factors did not differ between groups. Sixteen patients had G2 and 83 patients G3. Based on the ITT (intention-to-treat) analysis, 68% [55%; 81%] in Group A and 57% [43%; 71%] in Group B achieved SVR (p= 0.31). The primary endpoint of better SVR rates in Group A compared to a historical control group (SVR 70%) was not met. In conclusion, approximately 23% of G2/3 patients did not achieve RVR in a real world setting. However, subsequent recruitment in a treatment-extension study was difficult. Prolonged therapy beyond 24 weeks did not result in higher SVR compared to a historical control group. TRIAL REGISTRATION: ClinicalTrials.gov NCT00803309.

Treatment of naïve patients with chronic hepatitis C genotypes 2 and 3 with pegylated interferon alpha and ribavirin in a real world setting: relevance for the new era of DAA.

Evidence based clinical guidelines are implemented to treat patients efficiently that include efficacy, tolerability but also health economic considerations. This is of particular relevance to the new direct acting antiviral agents that have revolutionized treatment of chronic hepatitis C. For hepatitis C genotypes 2/3 interferon free treatment is already available with sofosbuvir plus ribavirin. However, treatment with sofosbuvir-based regimens is 10-20 times more expensive compared to pegylated interferon alfa and ribavirin (PegIFN/RBV). It has to be discussed if PegIFN/RBV is still an option for easy to treat patients. We assessed the treatment of patients with chronic hepatitis C genotypes 2/3 with PegIFN/RBV in a real world setting according to the latest German guidelines. Overall, 1006 patients were recruited into a prospective patient registry with 959 having started treatment. The intention-to-treat analysis showed poor SVR (GT2 61%, GT3 47%) while patients with adherence had excellent SVR in the per protocol analysis (GT2 96%, GT3 90%). According to guidelines, 283 patients were candidates for shorter treatment duration, namely a treatment of 16 weeks (baseline HCV-RNA <800.000 IU/mL, no cirrhosis and RVR). However, 65% of these easy to treat patients have been treated longer than recommended that resulted in higher costs but not higher SVR rates. In conclusion, treatment with PegIFN/RBV in a real world setting can be highly effective yet similar effective than PegIFN± sofosbuvir/RBV in well-selected naïve G2/3 patients. Full adherence to guidelines could be further improved, because it would be important in the new era with DAA, especially to safe resources.

Absorption reconstruction improves biodistribution assessment of fluorescent nanoprobes using hybrid fluorescence-mediated tomography.

AIM: Fluorescence-mediated tomography (FMT) holds potential for accelerating diagnostic and theranostic drug development. However, for proper quantitative fluorescence reconstruction, knowledge on optical scattering and absorption, which are highly heterogeneous in different (mouse) tissues, is required. We here describe methods to assess these parameters using co-registered micro Computed Tomography (µCT) data and nonlinear whole-animal absorption reconstruction, and evaluate their importance for assessment of the biodistribution and target site accumulation of fluorophore-labeled drug delivery systems. METHODS: Besides phantoms with varying degrees of absorption, mice bearing A431 tumors were imaged 15 min and 48 h after i.v. injection of a fluorophore-labeled polymeric drug carrier (pHPMA-Dy750) using µCT-FMT. The outer shape of mice and a scattering map were derived using automated segmentation of the µCT data. Furthermore, a 3D absorption map was reconstructed from the trans-illumination data. We determined the absorption of five interactively segmented regions (heart, liver, kidney, muscle, tumor). Since blood is the main near-infrared absorber in vivo, the absorption was also estimated from the relative blood volume (rBV), determined by contrast-enhanced µCT. We compared the reconstructed absorption with the rBV-based values and analyzed the effect of using the absorption map on the fluorescence reconstruction. RESULTS: Phantom experiments demonstrated that absorption reconstruction is possible and necessary for quantitative fluorescence reconstruction. In vivo, the reconstructed absorption showed high values in strongly blood-perfused organs such as the heart, liver and kidney. The absorption values correlated strongly with the rBV-based absorption values, confirming the accuracy of the absorption reconstruction. Usage of homogenous absorption instead of the reconstructed absorption map resulted in reduced values in the heart, liver and kidney, by factors of 3.5, 2.1 and 1.4, respectively. For muscle and subcutaneous tumors, which have a much lower rBV and absorption, absorption reconstruction was less important. CONCLUSION: Quantitative whole-animal absorption reconstruction is possible and can be validated in vivo using the rBV. Usage of an absorption map is important when quantitatively assessing the biodistribution of fluorescently labeled drugs and drug delivery systems, to avoid a systematic underestimation of fluorescence in strongly absorbing organs, such as the heart, liver and kidney.

Genetic variation in IL28B and treatment-induced clearance of hepatitis C virus in HIV-positive patients with acute and chronic hepatitis C.

Recently, a IL28B (rs 12979860) gene polymorphism was identified as a predictor for response to hepatitis C virus-specific treatment in human immunodeficiency virus (HIV)-uninfected and -infected patients with chronic hepatitis C. In an analysis of HIV-infected patients with acute hepatitis C, we found that the IL28B genotype was associated with serum levels of hepatitis C virus RNA, g-GT, and CD4 cell count. In contrast to HIV-infected patients with chronic hepatitis C, the IL28B genotype was not significantly associated with treatment response rates in patients with acute hepatitis C. Thus, effects of the IL28B single-nucleotide polymorphism may differ in HIV-infected patients with chronic and acute hepatitis C.

The cytotoxic lymphocyte antigen 4 polymorphisms affect response to hepatitis C virus-specific therapy in HIV(+) patients with acute and chronic hepatitis C virus co-infection.

OBJECTIVE: Cytotoxic lymphocyte antigen 4 (CTLA4), a co-receptor expressed on T lymphocytes, is involved in the regulation of T-cell functions. Here, we analyzed the potential impact of the CTLA4 polymorphisms on response to hepatitis C virus (HCV)-specific treatment in HIV(+) patients co-infected with HCV. PATIENTS AND METHODS: A total of 184 HIV/HCV co-infected Caucasian patients were enrolled into this study, including 109 patients with chronic and 75 patients with acute hepatitis C. CTLA4 genotypes were determined by LightCycler PCR. RESULTS: We found the CTLA4 -318 C/C genotype to be associated with sustained virological response in HCV/HIV co-infection (P = 0.035). Moreover, response rates were significantly higher in patients with a +49G/G genotype [23/29 (79.3%)] than in carriers of other +49 genotypes [59/155 (38.1%); OR 6.2; P = 0.00005]. Of note, the CTLA4 +49G/G genotype was confirmed as an independent predictor for treatment response in both patients with acute and chronic hepatitis C. CONCLUSION: CTLA4 polymorphisms are associated with treatment-induced resolution of HCV infection in HIV co-infected patients. These findings underline the impact of genetic host factors for successful treatment.