Translation of Ontological Concepts from English into German Using Commercial Translation Software and Expert Evaluation.

Medical ontologies are mostly available in English. This presents a language barrier that is a limitation in research and automated processing of patient data. The manual translation of ontologies is complex and time-consuming. However, there are commercial translation tools that have shown promising results in the field of medical terminology translation. The aim of this study is to translate selected terms of the Human Phenotype Ontology (HPO) from English into German using commercial translators. Six medical experts evaluated the translation candidates in an iterative process. The results show commercial translators, with DeepL in the lead, provide translations that are positively evaluated by experts. With a broader study scope and additional optimization techniques, commercial translators could support and facilitate the process of translating medical ontologies.

Initial User-Centred Design of an AI-Based Clinical Decision Support System for Primary Care.

A clinical decision support system based on different methods of artificial intelligence (AI) can support the diagnosis of patients with unclear diseases by providing tentative diagnoses as well as proposals for further steps. In a user-centred-design process, we aim to find out how general practitioners envision the user interface of an AI-based clinical decision support system for primary care. A first user-interface prototype was developed using the task model based on user requirements from preliminary work. Five general practitioners evaluated the prototype in two workshops. The discussion of the prototype resulted in categorized suggestions with key messages for further development of the AI-based clinical decision support system, such as the integration of intelligent parameter requests. The early inclusion of different user feedback facilitated the implementation of a user interface for a user-friendly decision support system.

Enhancing HIV Patient Support Through Telehealth: Exploring Design Solutions.

In recent years, telemedicine has advanced significantly, offering new possibilities for improving healthcare and patient outcomes. This paper presents a telemedicine app for HIV patients, developed using a human-centered design approach. Designed to meet the diverse and specific needs of Pre-Exposure Prophylaxis (PrEP) users and Late Presenters (LP), the app is part of the COMTRAC-HIV Project at the University Hospital Frankfurt. Through interviews with HIV experts and healthcare professionals, initial design solutions were derived. The paper explores the app's design process, core functionalities, and future directions, aiming to provide comprehensive support for individuals living with HIV.

Interviews with HIV Experts for Development of a Mobile Health Application in HIV Care-A Qualitative Study.

The Communication and Tracing App HIV (COMTRAC-HIV) project aims to develop a mobile health application for integrated care of HIV patients due to the low availability of those apps in Germany. This study addressed organizational conditions and necessary app functionalities, especially for the care of late diagnosed individuals (late presenters) and those using pre-exposure prophylaxis. We followed a human-centered design approach and interviewed HIV experts in Germany to describe the context of use of the app. The interviews were paraphrased and analyzed with a qualitative content analysis. To define the context of use, user group profiles were defined and tasks derived, which will represent the functionalities of the app. A total of eight experts were included in the study. The results show that the app should include a symptom diary for entering symptoms, side effects, and their intensity. It offers chat/video call functionality for communication with an HIV expert, appointment organization, and sharing findings. The app should also provide medication overview and reminders for medications and appointments. This qualitative study is a first step towards the development of an app for HIV individuals in Germany. Further research includes involving patients in the initial app design and test design usability.

Diagnosis Support for Rare Diseases Using Phenotypic Profiles.

The common occurrence of characteristic symptoms can be used to infer diagnoses. The aim of this study is to show how syndrome similarity analysis using given phenotypic profiles can help in the diagnosis of rare diseases. HPO was used to map syndromes and phenotypic profiles. The system architecture described is planned to be implemented in a clinical decision support system for unclear diseases.

[Evaluation of the "TeleCOVID Hesse" project after 1 year in operation]. / Evaluation des Projekts "TeleCOVID Hessen" nach einjährigem Betrieb.

BACKGROUND: The SARS-CoV­2 pandemic posed unexpected challenges for hospitals worldwide and in addition to the supply emergency, simultaneously caused a high pressure to innovate. Due to the high number of cases of COVID-19 patients requiring intensive care, structured networking of hospitals gained particular importance. The tele-ICU communication platform TeleCOVID was developed to improve the quality of intensive care both by enabling teleconsultations and by supporting patient transfers. OBJECTIVE: The present study aimed to survey user experiences with TeleCOVID. The study investigated the extent to which the app is used, the user experiences of the participating hospitals, and the resulting implications for the further development of the telemedicine application. MATERIAL AND METHODS: A user survey was conducted in May 2022 using an online questionnaire. The survey contained both closed and open questions with a free text field. It was sent via the Hessian Ministry of Social Affairs and Integration (HMSI). All 135 hospitals in Hesse were contacted by e­mail and invited to participate in the study. The results of the closed questions were analyzed using descriptive statistics, and the results of the open questions were clustered and thematically summarized using qualitative content analysis. RESULTS: The study showed that TeleCOVID was used primarily for transfer requests, followed by the need for a treatment consultation without a transfer request. Most often, ECMO treatment or treatment in a hospital of a higher care level was required. The content analysis showed that users particularly rated the possibility of a data protection-compliant and structured transfer of patient data as advantageous. It is also worth mentioning that in almost 25% of the cases a transfer of patients could be prevented by TeleCOVID. Disadvantages frequently mentioned by respondents were the lack of connection to the electronic hospital information system, the increased time required for the registration process, and the poor primary accessibility of contact persons. CONCLUSION: In a further development of the application the connection to the electronic hospital information system should be considered particularly urgent. In addition, the time expenditure should be reduced by a simplified login process. Due to interface barriers, an alternative data infrastructure would also be conceivable to create interoperability. The introduction of a web client could also increase usability. The main beneficiaries of hospital networking are physicians and patients in a context associated with a high workload and specific medical issues. Continuation and expansion of the app to intensive care medicine and beyond are therefore recommended. In further studies on the project, personal interviews with decision makers could be useful to conduct a more targeted needs analysis.

The Diagnostic Efficacy of an App-based Diagnostic Health Care Application in the Emergency Room: eRadaR-Trial. A prospective, Double-blinded, Observational Study.

OBJECTIVE: To evaluate the diagnostic accuracy of the app-based diagnostic tool Ada and the impact on patient outcome in the emergency room (ER). BACKGROUND: Artificial intelligence-based diagnostic tools can improve targeted processes in health care delivery by integrating patient information with a medical knowledge base and a machine learning system, providing clinicians with differential diagnoses and recommendations. METHODS: Patients presenting to the ER with abdominal pain self-assessed their symptoms using the Ada-App under supervision and were subsequently assessed by the ER physician. Diagnostic accuracy was evaluated by comparing the App-diagnoses with the final discharge diagnoses. Timing of diagnosis and time to treatment were correlated with complications, overall survival, and length of hospital stay. RESULTS: In this prospective, double-blinded study, 450 patients were enrolled and followed up until day 90. Ada suggested the final discharge diagnosis in 52.0% (95% CI [0.47, 0.57]) of patients compared with the classic doctor-patient interaction, which was significantly superior with 80.9% (95% CI [0.77, 0.84], P <0.001). However, when diagnostic accuracy of both were assessed together, Ada significantly increased the accuracy rate (87.3%, P <0.001), when compared with the ER physician alone. Patients with an early time point of diagnosis and rapid treatment allocation exhibited significantly reduced complications ( P< 0.001) and length of hospital stay ( P< 0.001). CONCLUSION: Currently, the classic patient-physician interaction is superior to an AI-based diagnostic tool applied by patients. However, AI tools have the potential to additionally benefit the diagnostic efficacy of clinicians and improve quality of care.

Study protocol for a prospective, double-blinded, observational study investigating the diagnostic accuracy of an app-based diagnostic health care application in an emergency room setting: the eRadaR trial.

INTRODUCTION: Occurrence of inaccurate or delayed diagnoses is a significant concern in patient care, particularly in emergency medicine, where decision making is often constrained by high throughput and inaccurate admission diagnoses. Artificial intelligence-based diagnostic decision support system have been developed to enhance clinical performance by suggesting differential diagnoses to a given case, based on an integrated medical knowledge base and machine learning techniques. The purpose of the study is to evaluate the diagnostic accuracy of Ada, an app-based diagnostic tool and the impact on patient outcome. METHODS AND ANALYSIS: The eRadaR trial is a prospective, double-blinded study with patients presenting to the emergency room (ER) with abdominal pain. At initial contact in the ER, a structured interview will be performed using the Ada-App and both, patients and attending physicians, will be blinded to the proposed diagnosis lists until trial completion. Throughout the study, clinical data relating to diagnostic findings and types of therapy will be obtained and the follow-up until day 90 will comprise occurrence of complications and overall survival of patients. The primary efficacy of the trial is defined by the percentage of correct diagnoses suggested by Ada compared with the final discharge diagnosis. Further, accuracy and timing of diagnosis will be compared with decision making of classical doctor-patient interaction. Secondary objectives are complications, length of hospital stay and overall survival. ETHICS AND DISSEMINATION: Ethical approval was received by the independent ethics committee (IEC) of the Goethe-University Frankfurt on 9 April 2020 including the patient information material and informed consent form. All protocol amendments must be reported to and adapted by the IEC. The results from this study will be submitted to peer-reviewed journals and reported at suitable national and international meetings. TRIAL REGISTRATION NUMBER: DRKS00019098.

The Status Quo of Rare Diseases Centres for the Development of a Clinical Decision Support System - A Cross-Sectional Study.

Clinical decision support systems (CDSS) help to improve the diagnostics and treatment of rare diseases (RD). As one of four funded consortia of the Medical Informatics Initiative supported by the Federal Ministry of Education and Research (BMBF, Germany), MIRACUM develops a clinical decision support system (CDSS) for RD based on distributed data of ten university hospitals. The CDSS will be developed at the Rare Diseases Centres (RDC) of the MIRACUM consortium. Since it is essential to deliver decision support at the right time and place in the clinician's workflow, this study aimed to capture relevant information of the RDCs regarding patient admission and diagnostic process. Additionally, we investigated how patient documentation and digitalisation is performed at the centres. Therefore, we conducted a cross-sectional survey involving experts in the RDs domain to capture relevant information for the further development of a CDSS in RD. For each centre, one expert on RDs participated in the study (n=8). The survey identified several challenges regarding the reuse of patient data, e.g. the paper-based documentation of a patientâAZs medical history and coding of diagnoses using ICD-10. However, we noticed a relevant use of current software diagnosis support and a similarly performed diagnostic process in all RDC. Further studies are needed to get more detailed insights and to define specific requirements.

Finding the Needle in the Hay Stack: An Open Architecture to Support Diagnosis of Undiagnosed Patients.

Clinical Decision Support Systems (CDSS) are promising to support physicians in finding the right diagnosis of patients with rare diseases (RD). The MIRACUM consortium, which includes ten university hospitals in Germany, will establish a diagnosis support system for RD. This system conducts a similarity analysis on distributed clinical data with the aim to identify similar patient cases at each MIRACUM site to offer the physician a hint to a possible diagnosis.

Ongoing liver inflammation in patients with chronic hepatitis C and sustained virological response.

BACKGROUND: Novel direct-acting antiviral DAA combination therapies tremendously improved sustained virologic response (SVR) rates in patients with chronic HCV infection. SVR is typically accompanied by normalization of liver enzymes, however, hepatic inflammation, i.e. persistently elevated aminotransferase levels may persist despite HCV eradication. Aim: To investigate prevalence and risk factors for ongoing hepatic inflammation after SVR in two large patient cohorts. METHODS: This post-hoc analysis was based on prospectively collected demographic and clinical data from 834 patients with SVR after HCV treatment with either PegIFN- or DAA-based treatment regimens from the PRAMA trial (n = 341) or patients treated at our outpatient clinic (n = 493). RESULTS: We observed an unexpected high prevalence of post-SVR inflammation, including patients who received novel IFN-free DAA-based therapies. Up to 10% of patients had ongoing elevation of aminotransferase levels and another 25% showed aminotransferase activity above the so-called healthy range. Several baseline factors were independently associated with post-SVR aminotransferase elevation. Among those, particularly male gender, advanced liver disease and markers for liver steatosis were strongly predictive for persistent ALT elevation. The use of IFN-based antiviral treatment was independently correlated with post-SVR inflammation, further supporting the overall benefit of IFN-free combination regimens. CONCLUSION: This is the first comprehensive study on a large patient cohort investigating the prevalence and risk factors for ongoing liver inflammation after eradication of HCV. Our data show a high proportion of patients with ongoing hepatic inflammation despite HCV eradication with potential implications for the management of approximately one third of all patients upon SVR.

Baseline MELD score predicts hepatic decompensation during antiviral therapy in patients with chronic hepatitis C and advanced cirrhosis.

BACKGROUND AND AIMS: In patients with advanced liver cirrhosis due to chronic hepatitis C virus (HCV) infection antiviral therapy with peginterferon and ribavirin is feasible in selected cases only due to potentially life-threatening side effects. However, predictive factors associated with hepatic decompensation during antiviral therapy are poorly defined. METHODS: In a retrospective cohort study, 68 patients with HCV-associated liver cirrhosis (mean MELD score 9.18 ± 2.72) were treated with peginterferon and ribavirin. Clinical events indicating hepatic decompensation (onset of ascites, hepatic encephalopathy, upper gastrointestinal bleeding, hospitalization) as well as laboratory data were recorded at baseline and during a follow up period of 72 weeks after initiation of antiviral therapy. To monitor long term sequelae of end stage liver disease an extended follow up for HCC development, transplantation and death was applied (240 weeks, ± SD 136 weeks). RESULTS: Eighteen patients (26.5%) achieved a sustained virologic response. During the observational period a hepatic decompensation was observed in 36.8%. Patients with hepatic decompensation had higher MELD scores (10.84 vs. 8.23, p<0.001) and higher mean bilirubin levels (26.74 vs. 14.63 µmol/l, p<0.001), as well as lower serum albumin levels (38.2 vs. 41.1 g/l, p=0.015), mean platelets (102.64 vs. 138.95/nl, p=0.014) and mean leukocytes (4.02 vs. 5.68/nl, p=0.002) at baseline as compared to those without decompensation. In the multivariate analysis the MELD score remained independently associated with hepatic decompensation (OR 1.56, 1.18-2.07; p=0.002). When the patients were grouped according to their baseline MELD scores, hepatic decompensation occurred in 22%, 59%, and 83% of patients with MELD scores of 6-9, 10-13, and >14, respectively. Baseline MELD score was significantly associated with the risk for transplantation/death (p<0.001). CONCLUSIONS: Our data suggest that the baseline MELD score predicts the risk of hepatic decompensation during antiviral therapy and thus contributes to decision making when antiviral therapy is discussed in HCV patients with advanced liver cirrhosis.

Investigation of viral escape mutations within HCV p7 during treatment with amantadine in patients with chronic hepatitis C.

BACKGROUND: Combination of several direct-acting antiviral agents will be necessary to overcome viral resistance in interferon-free treatment regimens for chronic HCV infection. HCV p7 inhibitors may be part of such combination regimens. Understanding why amantadine, despite showing inhibition of HCV p7 in vitro, appears ineffective in clinical trials, may help in the design of novel HCV p7 inhibitors. So far it is unknown whether viral escape mutations within HCV p7 explain the ineffectiveness of amantadine in vivo. METHODS: Pretreatment HCV p7 was directly sequenced in 157 consecutive patients with chronic HCV genotype 1b infection who had been treated with amantadine/placebo plus pegylated interferon (PEG-IFN)-α2a/ribavirin within a multicentre clinical trial. Triple therapy was preceded by 2 weeks of amantadine/placebo monotherapy. In nine patients, clonal sequencing was performed at baseline and after 2 weeks of amantadine/placebo monotherapy. RESULTS: Changes of the relative frequency of amino acid substitutions by ≥20% between pretreatment and week 2 of monotherapy were considered potential resistance mutations if they were only found in patients receiving amantadine but not in patients receiving placebo. Seven substitutions fulfilling these criteria were identified in the subset of patients with clonal sequencing. However, none of these substitutions were associated with treatment outcome in the complete cohort of patients receiving triple therapy with amantadine. CONCLUSIONS: Potential viral escape mutations within HCV p7 do not seem to play a major role for treatment response to antiviral therapy with amantadine and PEG-IFN-α2a/ribavirin in patients with chronic HCV genotype 1b infection.

Serum microRNA-21 as marker for necroinflammation in hepatitis C patients with and without hepatocellular carcinoma.

BACKGROUND: MicroRNA-21 (miR-21) is up-regulated in tumor tissue of patients with malignant diseases, including hepatocellular carcinoma (HCC). Elevated concentrations of miR-21 have also been found in sera or plasma from patients with malignancies, rendering it an interesting candidate as serum/plasma marker for malignancies. Here we correlated serum miR-21 levels with clinical parameters in patients with different stages of chronic hepatitis C virus infection (CHC) and CHC-associated HCC. METHODOLOGY/PRINCIPAL FINDINGS: 62 CHC patients, 29 patients with CHC and HCC and 19 healthy controls were prospectively enrolled. RNA was extracted from the sera and miR-21 as well as miR-16 levels were analyzed by quantitative real-time PCR; miR-21 levels (normalized by miR-16) were correlated with standard liver parameters, histological grading and staging of CHC. The data show that serum levels of miR-21 were elevated in patients with CHC compared to healthy controls (P<0.001); there was no difference between serum miR-21 in patients with CHC and CHC-associated HCC. Serum miR-21 levels correlated with histological activity index (HAI) in the liver (r = -0.494, P = 0.00002), alanine aminotransferase (ALT) (r = -0.309, P = 0.007), aspartate aminotransferase (r = -0.495, P = 0.000007), bilirubin (r = -0.362, P = 0.002), international normalized ratio (r = -0.338, P = 0.034) and γ-glutamyltransferase (r = -0.244, P = 0.034). Multivariate analysis revealed that ALT and miR-21 serum levels were independently associated with HAI. At a cut-off dC(T) of 1.96, miR-21 discriminated between minimal and mild-severe necroinflammation (AUC = 0.758) with a sensitivity of 53.3% and a specificity of 95.2%. CONCLUSIONS/SIGNIFICANCE: The serum miR-21 level is a marker for necroinflammatory activity, but does not differ between patients with HCV and HCV-induced HCC.

Vitamin D deficiency and a CYP27B1-1260 promoter polymorphism are associated with chronic hepatitis C and poor response to interferon-alfa based therapy.

BACKGROUND & AIMS: Vitamin D is an important immune modulator and preliminary data indicated an association between vitamin D deficiency and sustained virologic response (SVR) rates in hepatitis C virus (HCV) genotype 1 patients. We, therefore, performed a comprehensive analysis on the impact of vitamin D serum levels and of genetic polymorphisms with functional relevance within the vitamin D cascade on chronic hepatitis C and its treatment. METHODS: Vitamin D serum levels, genetic polymorphisms within the vitamin D receptor and 1α-hydroxylase were determined in a cohort of 468 HCV genotype 1, 2, and 3 infected patients who were treated with interferon-alfa based regimens. RESULTS: Chronic hepatitis C was associated with a high incidence of severe vitamin D deficiency compared to controls (25(OH)D(3)<10 ng/ml in 25% versus 12%, p<0.00001). 25(OH)D(3) deficiency correlated with SVR in HCV genotype 2 and 3 patients (50% and 81% SVR for patients with and without severe vitamin D deficiency, respectively, p<0.0001). In addition, the CYP27B1-1260 promoter polymorphism rs10877012 had substantial impact on 1,25-dihydroxyvitamin D serum levels (72, 61, and 60 pmol/ml for rs10877012 AA, AC, and CC, respectively, p=0.04) and on SVR rates in HCV genotype 1, 2, and 3 infected patients (77% and 65% versus 42% for rs10877012 AA, AC, and CC, respectively, p=0.02). CONCLUSIONS: Chronic hepatitis C virus infection is associated with vitamin D deficiency. Reduced 25-hydroxyvitamin D levels and CYP27B1-1260 promoter polymorphism leading to reduced 1,25-dihydroxyvitamin D levels are associated with failure to achieve SVR in HCV genotype 1, 2, and 3 infected patients.

Serum lipids in European chronic HCV genotype 1 patients during and after treatment with pegylated interferon-α-2a and ribavirin.

AIMS: Chronic hepatitis C alters the host's lipid metabolism and hepatitis C virus (HCV) eradication may be followed by an increase of serum cholesterol to adverse levels. We therefore aimed to determine the impact of chronic hepatitis C and its treatment on circulating lipids in a large European cohort of HCV genotype 1 patients. METHODS: The serum lipid profile of 575 HCV genotype 1-infected patients was characterized before, during and after treatment with pegylated interferon-α-2a (180 µg/week) and ribavirin (1000-1200 mg/day) for 48 weeks within a randomized controlled clinical trial. RESULTS: Total baseline cholesterol levels were significantly higher in patients with sustained virologic response (SVR) compared to nonresponders/relapsers (177 vs. 167 mg/dl, P=0.01), and low-cholesterol levels were an independent negative predictor of SVR (P=0.084). During the antiviral treatment, cholesterol levels substantially decreased as a putative marker of interferon-activity, but rebounded above baseline in patients with SVR (177-188 mg/dl, P=0.02), and to baseline in nonresponders/relapsers. Proportions of patients with cholesterol (>240 mg/dl) at baseline and after HCV eradication were 4 and 6%, respectively. Significant differences of triglyceride levels in patients with and without SVR were only observed at follow-up (136 and 117 mg/dl, respectively, P=0.028) but not at baseline. CONCLUSION: Our study reports a substantial pretreatment hypocholesterolemia in European HCV genotype 1 patients with nonresponse to interferon-α-based therapy and lower pretreatment cholesterol levels were an independent predictor of not attaining SVR. After treatment-induced HCV eradication median cholesterol levels increased above baseline, but the proportion of patients with high-risk cholesterol levels remained relatively low.

Influence of amantadine on CD81 expression on lymphocytes in chronic hepatitis C.

INTRODUCTION: Interferon alpha (IFN) down regulates CD81 expression on peripheral blood mononuclear cells (PBMC) in patients with chronic hepatitis C virus (HCV) infection. Aim of our study was to investigate whether amantadine alters IFN associated down regulation of CD81 expression on PBMC in patients with chronic hepatitis C. METHODS: Nineteen patients with chronic HCV infection received peginterferon alpha-2a/ribavirin (SOC) for 48 weeks. Patients were randomised to 12 weeks amantadine therapy (n=12) or no additional treatment (n=7). FACS analysis of CD81 expression on CD4(+), CD8(+), CD19(+), and CD56(+) cells was performed at baseline, week (TW) 4, TW12, and TW24 of antiviral therapy. RESULTS: A significant decline of CD81 expression was observed on CD4(+), CD8(+), and CD56(+) cells (p=0.011, p<0.001, p=0.015, respectively) but not on CD19(+) cells (p>0.2). CD81 expression on CD4(+), CD8(+), CD19(+), and CD56(+) cells was not different between patients treated with SOC plus amantadine and patients treated with SOC alone. CONCLUSION: The current study confirms that CD81 expression is down regulated by SOC on CD4(+), CD8(+) and CD56(+) cells. Amantadine treatment was not associated with CD81 expression. Interaction between amantadine and CD81 is unlikely to be involved in potential antiviral activity of amantadine in chronic HCV infection.

Placebo-controlled trial of 400 mg amantadine combined with peginterferon alfa-2a and ribavirin for 48 weeks in chronic hepatitis C virus-1 infection.

UNLABELLED: The impact of amantadine on virologic response rates of interferon-based treatment of chronic hepatitis C is controversial. The aim of this study was to compare virological response rates in patients with chronic hepatitis C virus (HCV)-1 infection treated with 400 mg amantadine or placebo in combination with peginterferon alfa-2a (40 kD) and ribavirin for 48 weeks. Seven hundred four previously untreated chronically HCV-1-infected patients (mean age, 46 +/- 12 years) were randomized to (A) amantadine-sulphate (400 mg/day) (n = 352) or (B) placebo (n = 352), both in combination with 180 microg peginterferon alfa-2a once weekly and ribavirin (1000-1200 mg/day) for 48 weeks. End of treatment and sustained virological response after a 24-week follow-up period were assessed by qualitative reverse transcription polymerase chain reaction (RT-PCR) (sensitivity, 50 IU/mL). Demographic and baseline virological parameters were similar in both treatment groups. In groups A and B, 231 of 352 patients (66%) and 256 of 352 patients (72%) achieved an end of treatment response, and 171 of 352 patients (49 %) and 186 of 352 patients (53 %) a sustained virological response, respectively. On-treatment dropout rate in the amantadine group was significantly higher than in the placebo group (32% versus 23%; P = 0.01). However, adverse events and laboratory abnormalities were similar between both groups. Per-protocol analysis revealed similar sustained virological response rates in both treatment groups (53% versus 55%). CONCLUSION: In this large placebo-controlled multicenter study, amantadine even at a dose of 400 mg/day did not improve virological response rates of peginterferon alfa-2a and ribavirin in patients with chronic genotype HCV-1 infection.

HCV-specific T-cell response in relation to viral kinetics and treatment outcome (DITTO-HCV project).

BACKGROUND & AIMS: The second slope of viral decline induced by interferon treatment has been suggested to be influenced mainly by the hepatitis C virus (HCV)-specific T-cell response; however, this hypothesis needs to be validated by results derived from experimental studies. METHODS: To address this issue, the HCV-specific T-cell response of 32 genotype-1-infected patients of the 270 patients enrolled in the dynamically individualized treatment of hepatitis C infection and correlates of viral/host dynamics phase III, open-label, randomized, multicenter trial was studied in relation to viral kinetics and treatment outcome. RESULTS: Greater proliferative responses by HCV-specific CD8 cells were found before treatment in patients with a fast viral decline and with a sustained viral response. However, no significant improvement of HCV-specific CD8 responses was observed in the first weeks of therapy in both rapid viral responder and non-rapid viral responder patients. A mild enhancement of proliferative T-cell responses and a partial restoration of the cytotoxic T-cell potential was expressed only late during treatment, likely favored by HCV clearance. CONCLUSIONS: Early restoration of an efficient T-cell response does not seem to be an essential requirement for a rapid viral decline in the first weeks of treatment. However, patients presenting a better HCV-specific CD8 cell proliferative potential at baseline are more likely to present a rapid and sustained viral response. Therefore, future treatment protocols should consider the development of strategies aimed at improving HCV-specific T-cell responses.