Management of Hepatitis C Antiviral Therapy Adverse Effects

Evaluation of machine learning algorithms for predicting direct-acting antiviral treatment failure among patients with chronic hepatitis C infection

Despite the availability of efficacious direct-acting antiviral (DAA) therapy, the number of people infected with hepatitis C virus (HCV) continues to rise, and HCV remains a leading cause of liver-related morbidity, liver transplantation, and mortality. We developed and validated machine learning (ML) algorithms to predict DAA treatment failure. Using the HCV-TARGET registry of adults who initiated all-oral DAA treatment, we developed elastic net (EN), random forest (RF), gradient boosting machine (GBM), and feedforward neural network (FNN) ML algorithms. Model performances were compared with multivariable logistic regression (MLR) by assessing C statistics and other prediction evaluation metrics. Among 6525 HCV-infected adults, 308 patients (4.7%) experienced DAA treatment failure. ML models performed similarly in predicting DAA treatment failure (C statistic [95% CI]: EN, 0.74 [0.69-0.79]; RF, 0.74 [0.69-0.80]; GBM, 0.72 [0.67-0.78]; FNN, 0.75 [0.70-0.80]), and all 4 outperformed MLR (C statistic [95% CI]: 0.51 [0.46-0.57]), and EN used the fewest predictors (n = 27). With Youden index, the EN had 58.4% sensitivity and 77.8% specificity, and nine patients were needed to evaluate to identify 1 DAA treatment failure. Over 60% treatment failure were classified in top three risk decile subgroups. EN-identified predictors included male sex, treatment < 8 weeks, treatment discontinuation due to adverse events, albumin level < 3.5 g/dL, total bilirubin level > 1.2 g/dL, advanced liver disease, and use of tobacco, alcohol, or vitamins. Addressing modifiable factors of DAA treatment failure may reduce the burden of retreatment. Machine learning algorithms have the potential to inform public health policies regarding curative treatment of HCV.

SURPASS-ET: phase III study of ropeginterferon alfa-2b versus anagrelide as second-line therapy in essential thrombocythemia

Patients diagnosed with high-risk essential thrombocythemia (ET) have limited treatment options to reduce the risk of thrombosis and lessen the progression of the disease by targeting the molecular source. Hydroxyurea is the recommended treatment, but many patients experience resistance or intolerance. Anagrelide is an approved second-line option for ET, but concerns of a higher frequency of disease transformation may affect its role as a suitable long-term option. Interferons have been evaluated in myeloproliferative neoplasms for over 30 years, but early formulations had safety and tolerability issues. SURPASS-ET (NCT04285086) is a phase III, open-label, multicenter, global, randomized, active-controlled trial that will evaluate the safety, efficacy, tolerability and pharmacokinetics of ropeginterferon alfa-2b compared with anagrelide as second-line therapy in high-risk ET.

Digestive system involvement and clinical outcomes among COVID-19 patients: A retrospective cohort study from Qatar

BACKGROUND

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 virus most commonly presents with respiratory symptoms. While gastrointestinal (GI) manifestations either at presentation or during hospitalization are also common, their impact on clinical outcomes is controversial. Some studies have described worse outcomes in COVID-19 patients with GI symptoms, while others have shown either no association or a protective effect. There is a need for consistent standards to describe GI symptoms in COVID-19 patients and to assess their effect on clinical outcomes, including mortality and disease severity.

AIM

To investigate the prevalence of GI symptoms in hospitalized COVID-19 patients and their correlation with disease severity and clinical outcomes.

METHODS

We retrospectively reviewed 601 consecutive adult COVID-19 patients requiring hospitalization between May 1-15, 2020. GI symptoms were recorded at admission and during hospitalization. Demographic, clinical, laboratory, and treatment data were retrieved. Clinical outcomes included all-cause mortality, disease severity at presentation, need for intensive care unit (ICU) admission, development of acute respiratory distress syndrome, and need for mechanical ventilation. Multivariate logistic regression model was used to identify independent predictors of the adverse outcomes.

RESULTS

The prevalence of any GI symptom at admission was 27.1% and during hospitalization was 19.8%. The most common symptoms were nausea (98 patients), diarrhea (76 patients), vomiting (73 patients), and epigastric pain or discomfort (69 patients). There was no difference in the mortality between the two groups (6.21% vs 5.5%, P = 0.7). Patients with GI symptoms were more likely to have severe disease at presentation (33.13% vs 22.5%, P < 0.001) and prolonged hospital stay (15 d vs 14 d, P = 0.04). There was no difference in other clinical outcomes, including ICU admission, development of acute respiratory distress syndrome, or need for mechanical ventilation. Drugs associated with the development of GI symptoms during hospitalization were ribavirin (diarrhea 26.37% P < 0.001, anorexia 17.58%, P = 0.02), hydroxychloroquine (vomiting 28.52%, P = 0.009) and lopinavir/ritonavir (nausea 32.65% P = 0.049, vomiting 31.47% P = 0.004, and epigastric pain 12.65% P = 0.048). In the multivariate regression analysis, age > 65 years was associated with increased mortality risk [odds ratio (OR) 7.53, confidence interval (CI): 3.09-18.29, P < 0.001], ICU admission (OR: 1.79, CI: 1.13-2.83, P = 0.012), and need for mechanical ventilation (OR: 1.89, CI:1.94-2.99, P = 0.007). Hypertension was an independent risk factor for ICU admission (OR: 1.82, CI:1.17-2.84, P = 0.008) and need for mechanical ventilation (OR: 1.66, CI: 1.05-2.62, P = 0.028).

CONCLUSION

Patients with GI symptoms are more likely to have severe disease at presentation; however, mortality and disease progression is not different between the two groups.

Hepatitis C Treatment by Nonspecialist Providers in the Direct-acting Antiviral Era

BACKGROUND

Hepatitis C virus (HCV) remains under-treated in the United States and treatment by nonspecialist providers can expand access. We compare HCV treatment provision and treatment completion between nonspecialist and specialist providers.

METHODS

This retrospective study used claims data from the Healthcare Cost Institute from 2013 to 2017. We identified providers who prescribed HCV therapy between 2013 and 2017, and patients enrolled in private insurance or Medicare Advantage who had pharmacy claims for HCV treatment. We measured HCV treatment completion, determined based on prescription fills for the minimum expected duration of the antiviral regimen. Using propensity score-weighted regression, we compared the likelihood of early treatment discontinuation by the type of treating provider.

RESULTS

The number of providers prescribing HCV treatment peaked in 2015 and then declined. The majority were gastroenterologists, although the proportion of general medicine providers increased to 17% by 2017. Among the 23,463 patients analyzed, 1008 (4%) discontinued before the expected minimum duration. In the propensity score-weighted analysis, patients treated by general medicine physicians had similar odds of treatment discontinuation compared with those treated by gastroenterologists [odds ratio (OR)=1.00, 95% confidence interval (CI): 0.99-1.01, P=0.45]. Results were similar when comparing gastroenterologists to nonphysician providers (OR=1.00, 95% CI: 0.99-1.01, P=0.53) and infectious diseases specialists (OR=1.00, 95% CI: 0.99-1.01, P=0.71).

CONCLUSIONS

HCV treatment providers remain primarily gastroenterologists, even in the current simplified treatment era. Patients receiving treatment from general medicine or nonphysician providers had a similar likelihood of treatment completion, suggesting that removing barriers to the scale-up of treatment by nonspecialists may help close treatment gaps for hepatitis C.

Current and Promising Antivirals Against Chikungunya Virus

Chikungunya virus (CHIKV) is the causative agent of chikungunya fever (CHIKF) and is categorized as a(n) (re)emerging arbovirus. CHIKV has repeatedly been responsible for outbreaks that caused serious economic and public health problems in the affected countries. To date, no vaccine or specific antiviral therapies are available. This review gives a summary on current antivirals that have been investigated as potential therapeutics against CHIKF. The mode of action as well as possible compound targets (viral and host targets) are being addressed. This review hopes to provide critical information on the in vitro efficacies of various compounds and might help researchers in their considerations for future experiments.

Potential Anti-SARS-CoV-2 Therapeutics That Target the Post-Entry Stages of the Viral Life Cycle: A Comprehensive Review

The coronavirus disease-2019 (COVID-19) pandemic continues to challenge health care systems around the world. Scientists and pharmaceutical companies have promptly responded by advancing potential therapeutics into clinical trials at an exponential rate. Initial encouraging results have been realized using remdesivir and dexamethasone. Yet, the research continues so as to identify better clinically relevant therapeutics that act either as prophylactics to prevent the infection or as treatments to limit the severity of COVID-19 and substantially decrease the mortality rate. Previously, we reviewed the potential therapeutics in clinical trials that block the early stage of the viral life cycle. In this review, we summarize potential anti-COVID-19 therapeutics that block/inhibit the post-entry stages of the viral life cycle. The review presents not only the chemical structures and mechanisms of the potential therapeutics under clinical investigation, i.e., listed in clinicaltrials.gov, but it also describes the relevant results of clinical trials. Their anti-inflammatory/immune-modulatory effects are also described. The reviewed therapeutics include small molecules, polypeptides, and monoclonal antibodies. At the molecular level, the therapeutics target viral proteins or processes that facilitate the post-entry stages of the viral infection. Frequent targets are the viral RNA-dependent RNA polymerase (RdRp) and the viral proteases such as papain-like protease (PLpro) and main protease (Mpro). Overall, we aim at presenting up-to-date details of anti-COVID-19 therapeutics so as to catalyze their potential effective use in fighting the pandemic.

Critical View on the Usage of Ribavirin in Already Existing Psychostimulant-Use Disorder

Substance-use disorder represents a frequently hidden non-communicable chronic disease. Patients with intravenous drug addiction are at high risk of direct exposure to a variety of viral infections and are considered to be the largest subpopulation infected with the hepatitis C virus. Ribavirin is a synthetic nucleoside analog that has been used as an integral component of hepatitis C therapy. However, ribavirin medication is quite often associated with pronounced psychiatric adverse effects. It is not well understood to what extent ribavirin per se contributes to changes in drug-related neurobehavioral disturbances, especially in the case of psychostimulant drugs, such as amphetamine. It is now well-known that repeated amphetamine usage produces psychosis in humans and behavioral sensitization in animals. On the other hand, ribavirin has an affinity for adenosine A1 receptors that antagonistically modulate the activity of dopamine D1 receptors, which play a critical role in the development of behavioral sensitization. This review will focus on the current knowledge of neurochemical/ neurobiological changes that exist in the psychostimulant drug-addicted brain itself and the antipsychotic-like efficiency of adenosine agonists. Particular attention will be paid to the potential side effects of ribavirin therapy, and the opportunities and challenges related to its application in already existing psychostimulant-use disorder.

Comparing drug safety of hepatitis C therapies using post-market data

BACKGROUND

Hepatitis C affects about 3 % of the world's population. In the United States, about 3.5 million have chronic hepatitis C, and it is the leading cause of liver cancer and the most common indication for liver transplantation. In the last decades, new advances in therapy have substantially increased the cure rate of hepatitis C to more than 95% with the use of antiviral agents. However, drug safety of the new treatments remains one of the major concerns. Data from the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) and the Electronic Health Record (EHR) systems provide crucial post-market information to evaluate drug safety. Currently, quantitative evidence of drug safety of hepatitis C treatments based on post-market data are still limited, and there is also a lack of a standard statistical procedure to systematically compare drug safety across multiple drugs using FAERS and EHR.

METHOD

In this study, we presented a statistical procedure to compare the difference in adverse events (AE) across multiple hepatitis C drugs using data from FAERS and EHR, and to assess the consistency of results from two data bases. Through three major steps, including descriptive comparison, testing for difference among groups, and quantification of association, the proposed method can provide a quantitative comparison on safety of multiple drugs. Specifically, we compared drugs that were approved by FDA to treat hepatitis C before 2011versus those approved after 2013. We used spontaneous AE reports submitted between 2004 to 2015 from FAERS data base and medical records between 1999 to 2015 from the Cerner health facts data base to estimate and compare the rate of AE after drug use.

RESULT

We studied 30 most frequently reported AEs after treatment of hepatitis C, comparing the difference between drugs approved before 2011versus those approved after 2013. Our results showed that there was difference in rate of AE between the two groups of treatment. We reported the AEs that have significant statistical difference, and estimate the difference attributable to variation of age and gender between the two groups of drug users. Our findings are consistent with results in existing literature. Moreover, we compared the results obtained from FAERS data and EHR data, and evaluated the consistency of evidence.

CONCLUSION

The proposed procedure is a general and standardized pipeline that can be used to compare and visualize drug safety among multiple drugs to support regulatory decision-makings using post-market data. We showed that there was statistically significant difference in AE rates between the new and old therapies for hepatitis C. We showed that both FAERS and EHR contained large information for research of post-market drug safety, but each has its own strength and limitations. Cautions should be taken when combining evidence from the two data resources and there is a need of more sophisticated informatics and statistical tools for evidence synthesis.

Demographic profile, host, disease & viral predictive factors of response in patients with chronic hepatitis C virus infection at a tertiary care hospital in north India

Background & objectives:

Standard of care for chronic hepatitis C (CHC) in India is peginterferon and ribavirin (RBV). The response to treatment in real life stetting is unclear. The objectives of this study were to evaluate the demographic profile and assess the virological response and predictors of response in CHC patients.

Methods:

Consecutive patients with CHC were included in this study. Detailed clinical history, risk factors, and predictive factors of response were noted. Patients were treated with peginterferon α2b (1.5 µg/kg/wk) and RBV (12 mg/kg/day) for 6 to 18 months based on response.

Results:

A total of 211 patients were included in the analysis, mean age 40.6±12.3 yr, 144 (68%) were males and 71 (34%) had compensated cirrhosis. Commonest risk factor for acquiring CHC was previous transfusion and surgery (51%). Genotype 3 (72%) was most common followed by genotype 1 (23%). Overall sustained virologic response (SVR) was 64 per cent [95% CI 57.1%-70.4%]. The SVR was 66.5 per cent [95% CI 58.34-73.89%] for genotype 3 and 61.2 per cent [95% CI 46.23 to 74.80%] for genotype 1. Non-cirrhotics had better SVR rates compared to cirrhotics (76 vs 41%, P<0.001). On multivariate analysis, BMI ≥23 kg/m², HOMA-IR ≥2, compliance (≤80%), and fibrosis >2 were predictors of low SVR.

Interpretation & conclusions:

Genotype 3 was the commonest HCV genotype. The commonest source of infection was previous transfusion and surgery. SVR rates for genotypes 3 were better than genotype 1 patients. Predictors of non-response were high BMI, insulin resistance, significant fibrosis and inadequate compliance.

The Role of Direct-acting Antivirals in the Treatment of Children with Chronic Hepatitis C

In the United States, chronic infection with the hepatitis C virus (HCV) affects an estimated 0.1-2% of the pediatric population, who are consequently at risk for major complications, including cirrhosis, hepatocellular carcinoma, and death. The current standard of treatment for chronic hepatitis C (CHC) in children is pegylated-interferon-alpha (PEG-IFN) in combination with ribavirin. PEG-IFN/ribavirin therapy is approved for children ages 3 and older; however, it is often held from use until adulthood because of its extensive list of potential side effects and high likelihood of causing adverse symptoms. While CHC is usually indolent in children and adolescents, immediately treating and curbing the spread of HCV before adulthood is important, as there can be transmission to other individuals via sexual activity and infected females can later vertically transmit the infection during pregnancy, the latter representing the most common means of transmission for children in the United States. The recent development of direct-acting antivirals has shown promising results in clinical trials for use in children and has dramatically increased the rates of sustained virological response in adults while improving side effect profiles as compared to interferon-based treatments. Given the usually indolent course of CHC in children, significant side effects of the currently-approved PEG-IFN/ribavirin therapy, and likely availability of all-oral interferon-free regimens for children within a few years, deferring treatment in clinically-stable children with CHC in anticipation of upcoming superior treatment modalities may be justified.

The prevalence and impact of thrombocytopenia, anaemia and leucopenia on sustained virological response in patients receiving hepatitis C therapy: evidence from a large 'real world' cohort

OBJECTIVES

The aim of the study was to explore the extent of thrombocytopenia (TCP), anaemia and leucopenia in patients with hepatitis C and evaluate how they impact the management of antiviral therapy, the attainment of sustained virological response (SVR), and some therapy-related adverse events.

MATERIALS AND METHODS

The Scottish Hepatitis C Clinical Database was used in this retrospective study. The prevalence of TCP, anaemia and leucopenia was evaluated. The impact of the three deficiencies on antiviral therapy management, serious adverse events and SVR attainment was assessed in patients who received therapy.

RESULTS

The prevalence of TCP, anaemia and leucopenia was 18.5, 0.9 and 0.2% among 4907 treated patients at baseline, increasing to 72, 25.8 and 5.4% during treatment, respectively. Dose reduction occurred in 29.3% of the patients without TCP; this percentage was higher in those with baseline TCP (53%) and in those who acquired it during treatment (35%). Similar results were found for anaemia and leucopenia. Baseline TCP (odds ratio=0.67, P<0.001) and baseline anaemia (odds ratio=0.43, P=0.03) were identified as risk factors associated with lower SVR rate; acquired TCP and anaemia were not associated with reduced SVR.

CONCLUSION

Baseline TCP or anaemia increased the risk of dose cessation. Patients who acquired TCP, anaemia or leucopenia during treatment did not exhibit compromised SVR rates, whereas patients with TCP or anaemia at baseline did. The potential benefit of growth factors in maintaining SVR rate is likely to be confined to those with baseline TCP or anaemia rather than to those who acquire it during therapy, where dose reduction does not appear to reduce the chance of SVR.

Inosine triphosphatase allele frequency and association with ribavirin-induced anaemia in Brazilian patients receiving antiviral therapy for chronic hepatitis C

Inosine triphosphatase (ITPA) single nucleotide polymorphisms (SNPs) are strongly associated with protection against ribavirin (RBV)-induced anaemia in European, American and Asian patients; however, there is a paucity of data for Brazilian patients. The aim of this study was to evaluate the ITPA SNP (rs7270101/rs1127354) frequency in healthy and hepatitis C virus (HCV)-infected patients from Brazil and the association with the development of severe anaemia during antiviral therapy. ITPA SNPs were determined in 200 HCV infected patients and 100 healthy individuals by sequencing. Biochemical parameters and haemoglobin (Hb) levels were analysed in 97 patients who underwent antiviral therapy. A combination of AArs7270101+CCrs1127354 (100% ITPase activity) was observed in 236/300 individuals. Anaemia was observed in 87.5% and 86.2% of treated patients with AA (rs7270101) and CC genotypes (rs1127354), respectively. Men with AA (rs7270101) showed a considerable reduction in Hb at week 12 compared to those with AC/CC (p = 0.1475). In women, there was no influence of genotype (p = 0.5295). For rs1127354, men with the CC genotype also showed a sudden reduction in Hb compared to those with AC. Allelic distribution of rs7270101 and rs1127354 shows high rates of the genotypes AA and CC, respectively, suggesting that the study population had a great propensity for developing RBV-induced anaemia. A progressive Hb reduction during treatment was observed; however, this reduction was greater in men at week 12 than in women.

Retreatment of Chronic Hepatitis C Infection with Telaprevir: Preliminary Results in Turkey

BACKGROUND

The use of pegylated interferon alpha and ribavirin (PegIFN/RBV) for the retreatment of chronic hepatitis C virus (HCV) infection without a sustained virological response (SVR) prior to PegIFN/RBV treatment has resulted in low success rates.

AIMS

To investigate the efficacy and safety of telaprevir (TVR) in combination with PegIFN/RBV in patients infected with HCV genotypes 1 and 4 who were previously treated with PegIFN/RBV and failed to achieve SVR.

STUDY DESIGN

Multi-center, retrospective, cross-sectional study.

METHODS

The study included 111 patients: 80 prior relapsers, 25 prior null responders, and six prior partial responders to PegIFN/RBV treatment. The patients were given TVR/PegIFN/RBV for 12 weeks, followed by a 12-week PegIFN/RBV treatment; virological response results were assessed at weeks 4, 12, and 24. Treatment was discontinued in patients with HCV RNA >1000 IU/mL at week 4 or with negative RNA results at week 4 but >1000 IU/mL at week 12. Rapid virological response (RVR), early virological response (EVR), extended rapid virological response (eRVR), and virological response at 24th week of treatment were evaluated. The side effects of combination therapy and the rates of treatment discontinuation were investigated.

RESULTS

The mean age of the patients was 56.02±9.96 years and 45.9% were male. Ninety-one percent of the patients were infected with viral genotype 1, 69.6% with the interleukin (IL) 28B genotype CT and 20.2% were cirrhotic. The RVR rate was 86.3% in prior relapsers, 56% in prior null responders, and 50% in prior partial responders (p=0.002). EVR rates in those groups were 91.3%, 56%, and 83.3%, respectively (p<0.001). eRVR rates were 83.8% in prior relapsers, 48% in prior null responders, and 50% in prior partial responders (<0.001). The virological response at the 24th week of treatment was found to be the highest in prior relapsers (88.8%); it was 56% in prior null responders and 66.7% in prior partial responders (p<0.001). Common side effects were fatigue, headache, anorexia, malaise, anemia, pruritus, dry skin, rash, dyspepsia, nausea, pyrexia, stomachache, and anorectal discomfort. All treatments were discontinued due to side effects in 9.9% of patients.

CONCLUSION

High virological response rates were obtained with TVR/PegIFN/RBV treatment. Although side effects were frequently observed, the discontinuation rate of combination therapy was low.

Chronic Hepatitis C Infection in Children: Current Treatment and New Therapies

Viral hepatitis C is responsible for a large burden of disease worldwide. Treatment of hepatitis C infection is currently undergoing a revolution with the development of new direct acting antivirals that offer higher cure rates and fewer side effects than other medications currently available. Treatment options for children, although well-defined and evidence-based, are limited relative to adults as there are few trials regarding the use of these newly developed agents in children. With so much optimism in the development of novel therapeutic options for hepatitis C, it is timely to review and summarize the current standard of care treatment and indications for treatment of chronic hepatitis C in children. We provide here an overview of recent drug developments and their potential for use in children.

New treatments for chronic hepatitis C: an overview for paediatricians

Pegylated interferon (IFN) α-2a or 2b in combination with ribavirin for children aged 3 years and older is the standard treatment for paediatric chronic hepatitis C. This treatment regimen was developed firstly in adults. In recent years, a number of direct-acting antiviral agents (DAAs) are under development for treatment of chronic hepatitis C virus (HCV) infection. These agents block viral replication inhibiting directly one of the several steps of HCV lifecycle. DAAs are classified into several categories based on their molecular target: HCV NS3/4A protease inhibitors, HCV NS5B polymerase inhibitors and HCV NS5A inhibitors. Other promising compounds are cyclophilin A inhibitors, mi-RNA122 and IFN-λ. Several new drugs associations will be developed in the near future starting from the actual standard of care. IFN-based and IFN-free regimens are being studied in adults. In this constantly evolving scenario new drug regimens targeted and suitable for children would be possible in the next future. Especially for children, it is crucial to identify the right combination of drugs with the highest potency, barrier to resistance and the best safety profile.

"Fighting an uphill battle": experience with the HCV triple therapy: a qualitative thematic analysis

Background

Hepatitis C virus (HCV) infections are a severe burden on public health worldwide, causing mortality rates triple that of the general population. Since 2011, for both therapy-naive and therapy-experienced genotype 1 patients, the first generation of direct acting antivirals (DAAs), i.e., the protease-inhibitors (PI) telaprevir and boceprevir have been added to existing dual therapies. The therapeutic effect of the resulting triple therapy is striking; however, treatment regimens are complex and commonly cause side effects. Little is known of how patients implement therapy in their daily lives, or of how they deal with these effects.

This study aims to describe HCV patients' experiences with protease-inhibitor-based triple therapy and their support needs.

Methods

A qualitative design was used. Patients from three outpatient clinics, with ongoing, completed or discontinued PI treatment experience were recruited using a maximum variation sampling approach. Open-ended interviews were conducted and analyzed using thematic analysis according to Braun & Clarke (Qual Res Psychol 3:77-101, 2006).

Results

Thirteen patients participated in the interviews. All described themselves as highly motivated to undergo treatment, since they saw the new therapy as a “real chance” for a cure. However, all later described the therapy period as a struggle. The constitutive theme–“Fighting an uphill battle”– describes the common existential experience of and negative consequences of coping with side effects. The processes that fostered this common experience followed three sub-themes: “encountering surprises”, “dealing with disruption” and “reaching the limits of systems”.

Conclusion

HCV patients undergoing outpatient protease-inhibitor-based triple therapy need systematic support in symptom management. This will require specially trained professionals to advise and support them and their families, and to provide rapid responses to their needs throughout this complex course of therapy. As the generation of DAAs for all genotypes, are expected to have less severe side effects, and many HCV patients require treatment, this knowledge can improve treatment support tremendously, especially for patients who are quite difficult to treat. Furthermore, these findings are helpful to illustrate development in HCV treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-507) contains supplementary material, which is available to authorized users.

Efeitos colaterais do uso da ribavirina, prednisona e DMSO em cães naturalmente infectados pelo vírus da cinomose

O estudo tem o objetivo de identificar efeitos indesejáveis da ribavirina, prednisona e DMSO em cães naturalmente infectados com o vírus da cinomose. Foram utilizados 60 cães apresentando quadro neurológico da cinomose com evolução de 10 dias. Os animais foram internados e receberam tratamento de suporte; foram avaliados diariamente e realizados hemograma, dosagem bioquímica e exame de urina tipo I. Os grupos 1 e 2 foram tratados com ribavirina e sua associação com DMSO; os grupos 3 e 4 com DMSO e prednisona e o grupos 5 com ribavirina e prednisona e o grupo 6 com ribavirina, prednisona e DMSO. Os animais foram anestesiados para a colheita de líquor, medula óssea e sangue, antes do tratamento para diagnóstico através da RT-PCR. As amostras negativas foram analisadas pela técnica de hn-PCR. Todos os animais apresentaram resultado positivo em pelo menos uma das duas reações. O efeito adverso da ribavirina e a sua associação com a prednisona foi a anemia hemolítica, que foi confirmada pela observação de bilirrubina na urina apenas dos cães tratados com ribavirina.

A new era in the treatment of chronic hepatitis C infection

Treatment of chronic hepatitis C virus (HCV) infection has evolved over the past three decades. At the start, treatment involved interferon monotherapy followed by combination therapy using interferon and ribavirin, and subsequently evolved to pegylated interferon (Peg-IFN) and ribavirin. In genotype 1 infection, rates of sustained virological response (SVR) are approximately 45 % with Peg-IFN and ribavirin, whereas SVR rates in genotypes 2 and 3 infections are as high as 70 % to 80 %. Side effects and cost related to these drugs are important concerns, particularly in countries like India where patients have to bear their health expenses. In the recent past, there has been a significant change in course with the on-going search and the development of more effective drugs in the management of HCV infection. Telaprevir and Boceprevir are two new potent protease inhibitors (direct acting antiviral or DAA agents) which, when administered with Peg-IFN and ribavirin, have shown to result significantly higher SVR rates in phase 3 studies in patients with genotype 1 infection, both in treatment naïve patients (up to 75 %) and those with previously failed therapy. Several other new antiviral agents some in combination with Peg-IFN and ribavirin and some in combination without Peg-IFN (IFN-free regimens) are currently being tested in patients with genotype 1, 2 and 3 infections and are expected to dramatically change the armamentarium of HCV therapy in the coming years.

Ischemic colitis during interferon-ribavirin therapy for chronic hepatitis C: A case report

Ischemic colitis is a rare complication of interferon administration. Only 9 cases in 6 reports have been described to-date. This report describes a case of ischemic colitis during pegylated interferon and ribavirin treatment for chronic hepatitis C, and includes a review of the relevant literature. A 48-year-old woman was treated with pegylated interferon α-2a and ribavirin for chronic hepatitis C, genotype Ib. After 19 wk of treatment, the patient complained of severe afebrile abdominal pain with hematochezia. Vital signs were stable and serum white blood cell count was within the normal range. Abdominal computed tomography showed diffuse colonic wall thickening from the splenic flexure to the proximal sigmoid colon, which is the most vulnerable area for the development of ischemic colitis. Colonoscopy revealed an acute mucosal hyperemic change, with edema and ulcerations extending from the proximal descending colon to the sigmoid colon. Colonic mucosal biopsy revealed acute exudative colitis. Polymerase chain reaction and culture for Mycobacterium tuberculosis were negative and the cultures for cytomegalovirus, Salmonella and Shigella species were negative. After discontinuation of interferon and ribavirin therapy, abdominal pain and hematochezia subsided and, following colonoscopy showed improvement of the mucosal ulcerations. Ischemic colitis cases during interferon therapy in patients with chronic hepatitis C reported so far have all involved the descending colon. Ischemic colitis is a rarely encountered complication of interferon administration in patients with chronic hepatitis C and should be considered when a patient complains of abdominal pain and hematochezia.

NASPGHAN practice guidelines: Diagnosis and management of hepatitis C infection in infants, children, and adolescents

Hepatitis C virus (HCV) is an RNA virus that affects >180 million individuals worldwide with a high propensity for chronic infection. Children with HCV infection differ from adults in several ways including some modes of transmission, rates of clearance, progression of fibrosis, and the duration of potential chronic infection when acquired at birth. Since the discovery of HCV in 1989, there have been significant advances in the understanding of the virology and natural history of chronic HCV infection in children. In addition, there are now several treatment options for children with chronic hepatitis C infection and many new therapies on the horizon. As a consequence, the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition brought together experts in pediatric hepatology to review the available data in children and provide clinicians with approaches to the diagnosis, management, and prevention of HCV infection in children and adolescents. The guideline details the epidemiology and natural history of HCV infection in children, the diagnostic workup, monitoring and treatment of disease, and provides an update on future treatment options and areas of research.

A pharmacological profile of ribavirin and monitoring of its plasma concentration in chronic hepatitis C infection

Chronic hepatitis C (CHC) infection, usually an asymptomatic infection, has long-term serious complications such as cirrhosis, hepatocellular carcinoma, and end-stage liver disease requiring liver transplantation (LT). Several novel drugs against hepatitis C which form part of 'specifically targeted antiviral therapy for hepatitis C' (STAT-C) have been developed. These include NS3/4A protease inhibitors telaprevir, boceprevir, and nucleoside/non-nucleoside polymerase inhibitors (NS5A) which hold promise for future therapy. Despite the development of new anti-hepatitis C virus (HCV) drugs, ribavirin (RBV) remains the single most important drug to prevent relapse and is frequently included among newer regimens being developed with novel small molecule anti-HCV drugs. The current approved treatment is a combination therapy of once weekly subcutaneous pegylated-interferon (PEG-IFN)-α plus body-weight-based oral RBV regimen. The most significant dose-dependent side effect of RBV is hemolytic anemia warranting dose reduction or discontinuation in severe cases compromising sustained virological response (SVR). Monitoring RBV plasma concentration has been challenging due to its peculiar pharmacokinetics and has been done to predict both efficacy and toxicity. Herein, we review the pharmacological profile of RBV and the monitoring of its plasma concentration, monitoring in renal impairment, post-LT, and human immunodeficiency virus (HIV)-HCV co-infection in patients being treated with combination therapy of PEG-IFN-α and RBV.