Pegylated interferons for the treatment of chronic hepatitis C: pharmacological and clinical differences between peginterferon-alpha-2a and peginterferon-alpha-2b

Asian elephant interferons alpha and beta and their anti-herpes viral activity

The type I interferons (IFNs) are a group of key cytokines of the vertebrate innate immune system that induce an antiviral state in uninfected cells. Experimental in-vitro and in-vivo data have proven the fundamental role these cytokines possess in the protective response to a wide variety of pathogens, including herpesviruses. In a clinical setting, IFNs have been an important treatment in humans for several decades and increasing evidence demonstrates their potential in controlling viral haemorrhagic fevers when administered early in disease. In juvenile Asian elephants, elephant endotheliotropic herpesvirus haemorrhagic disease (EEHV-HD) often proves fatal when an effective adaptive immune response cannot be mounted in time, suggesting that an enhancement of the innate immune response could provide protection. This study sequenced six members of the Asian elephant type I IFNs, most closely related to sequences from the African elephant and Florida manatee. Subsequently, recombinant Asian elephant IFNα and IFNβ proteins were expressed and assessed for bioactivity in-vitro, relative to recombinant human IFNs, using a novel infection model incorporating primary Asian elephant fibroblasts and bovine alphaherpesvirus 1 (BoHV-1) as a surrogate for EEHV. In a dose-dependent manner, both Asian elephant IFNs and human IFNα2a protected cells from BoHV-1 infection in this proof-of-concept study, even if applied up to 24 hours post-infection in-vitro.

Advancing Therapeutic Strategies with Polymeric Drug Conjugates for Nucleic Acid Delivery and Treatment

The effective clinical translation of messenger RNA (mRNA), small interfering RNA (siRNA), and microRNA (miRNA) for therapeutic purposes hinges on the development of efficient delivery systems. Key challenges include their susceptibility to degradation, limited cellular uptake, and inefficient intracellular release. Polymeric drug conjugates (PDCs) offer a promising solution, combining the benefits of polymeric carriers and therapeutic agents for targeted delivery and treatment. This comprehensive review explores the clinical translation of nucleic acid therapeutics, focusing on polymeric drug conjugates. It investigates how these conjugates address delivery obstacles, enhance systemic circulation, reduce immunogenicity, and provide controlled release, improving safety profiles. The review delves into the conjugation strategies, preparation methods, and various classes of PDCs, as well as strategic design, highlighting their role in nucleic acid delivery. Applications of PDCs in treating diseases such as cancer, immune disorders, and fibrosis are also discussed. Despite significant advancements, challenges in clinical adoption persist. The review concludes with insights into future directions for this transformative technology, underscoring the potential of PDCs to advance nucleic acid-based therapies and combat infectious diseases significantly.

Interferon α and β induce differential transcriptional and functional metabolic phenotypes in human macrophages and blunt glycolysis in response to antigenic stimuli

The impact of chronic exposure to type I interferons (IFN)-α2a, 2b, and β on macrophage metabolism, intimately linked to macrophage function, is not well understood. This study assesses the nuanced host responses induced by type I IFN cytokines, offering insights into potential therapeutic approaches in diseases associated with these cytokines. Employing a combination of transcriptional profiling and real-time functional analysis, we delineated metabolic reprogramming in response to chronic IFN exposure. Our results reveal distinct transcriptional metabolic profiles between macrophages chronically exposed to IFN-α and IFN-β. IFN-β significantly diminishes the oxygen consumption rate and glycolytic proton extrusion rate in macrophages. Conversely, IFN-α2b decreased parameters of mitochondrial fitness and induced a shift toward glutamine oxidation. Assessing the ability of macrophages to induce glycolysis in response to antigenic stimuli (LPS and iH37Rv), we found that chronic exposure to all IFN subtypes limited glycolytic induction. This study addresses a critical oversight in the literature, where individual roles of IFN subtypes are frequently amalgamated and lack distinction. These findings not only provide novel insights into the divergent effects of IFN-α2a, α2b, and β on macrophage metabolism but also highlight their potential implications for developing targeted therapeutic strategies.

Interferons in vitreoretinal diseases; a review on their clinical application, and mechanism of action

PURPOSE

This review investigates the therapeutic benefits of interferons (IFNs) in vitreoretinal diseases, focusing on their regulatory roles in innate immunological reactions and angiogenesis. The study aims to categorize the clinical outcomes of IFN applications and proposes a molecular mechanism underlying their action.

METHODS

A systematic review was conducted using MEDLINE/PubMed, Web of Science, EMBASE, and Google Scholar databases to identify randomized clinical trials, case series, and case-control studies related to IFNs' impact on vitreoretinal diseases (1990-2022). The data synthesis involved an in-depth analysis of the anti-inflammatory and anti-angiogenesis effects of IFNs across various studies.

RESULTS

Our findings indicate that IFNs exhibit efficacy in treating inflammation-associated vitreoretinal disorders. However, a lack of sufficient evidence exists regarding the suitability of IFNs in angiogenesis-associated vitreoretinal diseases like choroidal neovascularization and diabetic retinopathies. The synthesis of data suggests that IFNs may not be optimal for managing advanced stages of angiogenesis-associated disorders.

CONCLUSION

While IFNs emerge as promising therapeutic candidates for inflammation-related vitreoretinal diseases, caution is warranted in their application for angiogenesis-associated disorders, especially in advanced stages. Further research is needed to elucidate the nuanced molecular pathways of IFN action, guiding their targeted use in specific vitreoretinal conditions.

Subcutaneous panniculitic-like T-cell lymphoma localized to a site of peginterferon alfa-2a administration

T cell dyscrasias that demonstrate a proclivity for the subcutaneous fat include atypical lymphocytic lobular panniculitis, lupus profundus, and primary subcutaneous T cell lymphoma, including subcutaneous panniculitis-like T cell lymphoma (SPTCL). We encountered two patients who developed fever and indurated abdominal erythema at their peginterferon alfa-2a injection sites. Biopsies showed an atypical CD8 positive, granzyme positive, CD5 negative, MXA negative lymphocytic lobular panniculitis, diagnostic of SPTCL. Peginterferon alfa-2a was held in both patients. One patient received chemotherapy with an excellent response, while the other continued to have progressive disease. Peginterferon alfa-2a is known to significantly elevate serum MXA, which may induce high levels of MXA expression at the injection site, creating a microenvironment for the development of lupus profundus, which may eventuate into SPTCL. In summation, a potential risk of peginterferon alfa-2a injections is the development of SPTCL potentially arising in a background of an exogenous interferon triggered lymphocytic panniculitis.

Magnetic Relaxation Switching Assay Using IFNα-2b-Conjugated Superparamagnetic Nanoparticles for Anti-Interferon Antibody Detection

Type I interferons, particularly IFNα-2b, play essential roles in eliciting adaptive and innate immune responses, being implicated in the pathogenesis of various diseases, including cancer, and autoimmune and infectious diseases. Therefore, the development of a highly sensitive platform for analysis of either IFNα-2b or anti-IFNα-2b antibodies is of high importance to improve the diagnosis of various pathologies associated with the IFNα-2b disbalance. For evaluation of the anti-IFNα-2b antibody level, we have synthesized superparamagnetic iron oxide nanoparticles (SPIONs) coupled with the recombinant human IFNα-2b protein (SPIONs@IFNα-2b). Employing a magnetic relaxation switching assay (MRSw)-based nanosensor, we detected picomolar concentrations (0.36 pg/mL) of anti-INFα-2b antibodies. The high sensitivity of the real-time antibodies' detection was ensured by the specificity of immune responses and the maintenance of resonance conditions for water spins by choosing a high-frequency filling of short radio-frequency pulses of the generator. The formation of a complex of the SPIONs@IFNα-2b nanoparticles with the anti-INFα-2b antibodies led to a cascade process of the formation of nanoparticle clusters, which was further enhanced by exposure to a strong (7.1 T) homogenous magnetic field. Obtained magnetic conjugates exhibited high negative MR contrast-enhancing properties (as shown by NMR studies) that were also preserved when particles were administered in vivo. Thus, we observed a 1.2-fold decrease of the T2 relaxation time in the liver following administration of magnetic conjugates as compared to the control. In conclusion, the developed MRSw assay based on SPIONs@IFNα-2b nanoparticles represents an alternative immunological probe for the estimation of anti-IFNα-2b antibodies that could be further employed in clinical studies.

Trend analysis of hepatitis B and C among patients visiting health facility of Tigrai, Ethiopia, 2014-2019

BACKGROUND

Hepatitis B and C viruses are the major public health concerns of the globe. The two hepatotropic viruses share common modes of transmission and their co-infection is common. Despite the provision of an effective prevention mechanism, the infections caused by these viruses remain a significant problem worldwide, particularly among developing countries like Ethiopia.

METHODS

This institutional-based retrospective study was conducted between January 2014 December and December 2019 from documented laboratory logbooks of Adigrat general hospital serology laboratory, Tigrai, Ethiopia. data were collected and checked for completeness on a daily based, coded, entered, and cleaned using Epinfo version 7.1, exported and analyzed using SPSS version 23. Binary logistic regression analysis and Chi-square test (X²) assessed the association between dependent and independent variables. The corresponding variables with a P-value (P < 0.05) and 95% confidence interval were considered statistically significant.

RESULTS

Out of 20,935 clinically suspected individuals, 20,622 were given specimens and tested for hepatitis B and C viruses with total completeness of 98.5%. The overall prevalence of hepatitis B and hepatitis C virus was found to be 3.57% (689/19,273) and 2.13% (30/1,405), respectively. The positivity rate of the hepatitis B virus was 8.0% (106/1317) and 3.24% (583/17,956) among males and females, respectively. Additionally, 2.49%( 12/481) of males and 1.94% (18/924) of females were positive for hepatitis C virus infection. The overall prevalence of co-infection for both hepatitis B and hepatitis C virus was 7.4% (4/54). Sex and age were significantly associated with hepatitis B and C virus infection.

CONCLUSIONS

The overall prevalence of hepatitis B and C is low intermediate according to the WHO criteria. Although there was a fluctuating trend of hepatitis B and C through the years 2014-2019, the result shows moreover declining trend. Both hepatitis B and C share similar routes of transmission and affect all age categories but males were more highly affected than females. Therefore, awareness creation of the community about the methods of transmission, education about prevention, and control of hepatitis B and C virus infection, and improving coverage of youth-friendly services in health facilities should be strengthened.

Barriers and Facilitators to Hepatitis C Virus (HCV) Treatment for Aboriginal and Torres Strait Islander Peoples in Rural South Australia: A Service Providers' Perspective

This study explored the barriers and facilitators to hepatitis C virus (HCV) treatment for Aboriginal and Torres Strait Islander peoples in rural South Australia as viewed from a healthcare provider perspective in the era of direct acting antivirals (DAAs). Phase 1 was a qualitative systematic review examining the barriers and enablers to diagnosis and treatment amongst Indigenous peoples living with HCV worldwide. Phase 2 was a qualitative descriptive study with healthcare workers from six de-identified rural and regional Aboriginal Community-Controlled Health Services in South Australia. The results from both methods were integrated at the analysis phase to understand how HCV treatment could be improved for rural Aboriginal and Torres Strait Islander peoples. Five main themes emerged: the importance of HCV education, recognizing competing social and cultural demands, the impact of holistic care delivery and client experience, the effect of internal barriers, and overlapping stigma, discrimination, and shame determine how Indigenous peoples navigate the healthcare system and their decision to engage in HCV care. Continued efforts to facilitate the uptake of DAA medications by Aboriginal and Torres Strait peoples in rural areas should utilize a multifaceted approach incorporating education to community and cultural awareness to reduce stigma and discrimination.

Comparable HIV suppression by pegylated-IFN-α2a or pegylated-IFN-α2b during a 4-week analytical treatment interruption

We report on the post-hoc analysis of three clinical studies (NCT01935089, NCT00594880 and NCT00051818) with chronically HIV-infected, immune-reconstituted individuals with similar entry criteria, and demographics interrupting antiretroviral therapy (ART) without or with 5 weeks of weekly pegylated (Peg)-IFN-α2b or Peg-IFN-α2a immunotherapy added onto ART. Results show similar rates of viral suppression between both immunotherapies when continued during a 4-week ART interruption, despite Peg-IFN-α2a maintaining significantly higher trough blood levels.

Forms and Methods for Interferon's Encapsulation

Interferons (IFNs) are cytokines involved in the immune response that act on innate and adaptive immunity. These proteins are natural cell-signaling glycoproteins expressed in response to viral infections, tumors, and biological inducers and constitute the first line of defense of vertebrates against infectious agents. They have been marketed for more than 30 years with considerable impact on the global therapeutic protein market thanks to their diversity in terms of biological activities. They have been used as single agents or with combination treatment regimens, demonstrating promising clinical results, resulting in 22 different formulations approved by regulatory agencies. The 163 clinical trials with currently active IFNs reinforce their importance as therapeutics for human health. However, their application has presented difficulties due to the molecules' size, sensitivity to degradation, and rapid elimination from the bloodstream. For some years now, work has been underway to obtain new drug delivery systems to provide adequate therapeutic concentrations for these cytokines, decrease their toxicity and prolong their half-life in the circulation. Although different research groups have presented various formulations that encapsulate IFNs, to date, there is no formulation approved for use in humans. The current review exhibits an updated summary of all encapsulation forms presented in the scientific literature for IFN-α, IFN-ß, and IFN-γ, from the year 1996 to the year 2021, considering parameters such as: encapsulating matrix, route of administration, target, advantages, and disadvantages of each formulation.

A selective and sensitive UPLC-ESI-MS/MS method for quantification of Pegylated Interferon Alfa-2b in human serum using signature peptide-based quantitation

A sensitive method for determination of PEG-IFN-α-2b in human serum was developed using ultra performance liquid chromatography aligned with tandem mass spectrometric detection. A two-treatment, two-period, cross over study was conducted to establish bioequivalence between a test and reference formulation and the method was successfully applied to the quantification of PEG-IFN-α-2b in serum samples of this clinical study. The sample concentrations obtained from LC-MS/MS technique were compared with the concentrations obtained from ELISA technique. PEG-IFN-α-2b was isolated from serum using protein precipitation technique with isopropyl alcohol followed by overnight tryptic digestion. The signature peptide formed as result of tryptic digestion was separated on a chromatograph and detected using a mass detector. The mass transition ion-pair of m/z 741.3 → 1047.1 for PEG-IFN-α-2b and m/z 387.4 → 205.2 for internal standard were used for MS/MS detection. The sample extraction involves a simple protein precipitation method followed by tryptic digestion of the supernatant and further sample cleanup was not needed. The method has been validated over a linear range of 1.028-3200 ng/mL with a correlation coefficient ≥ 0.99. The precision (%RSD) was 5.52 to 7.90 and accuracy (%RE) was within -1.80 to 1.68. The total run time was 22.0 min. The sensitivity of LC-MS/MS method was 1.0 ng/ml which was found to be more sensitive than ELISA and resulted in improving the overall study data by being able to quantify all the samples without any below LOQ results helping to further improve the pharmacokinetic modeling. This improved method is a promising anti-body free LC-MS/MS based methodology for estimation of PEG-IFN-α-2b in human serum and may be applied for other such pegylated molecules.

Safety, Immune, and Antiviral Effects of Pegylated Interferon Alpha 2b Administration in Antiretroviral Therapy-Suppressed Individuals: Results of Pilot Clinical Trial

In the pilot NCT01935089 trial, we tested whether pegylated interferon alpha2b (Peg-IFN-α2b) with antiretroviral therapy (ART) was safe and could impact HIV and immune measures in blood and in gut-associated lymphoid tissue (GALT). Twenty HIV-1⁺ ART-suppressed individuals received 1 μg/kg/week Peg-IFN-α2b with ART for 20 weeks, with intermediate 4-week analytical ART interruption (ATI). Safety, immune activation, HIV viral load and integrated HIV DNA in blood, and HIV RNA and DNA in gut biopsies were measured. A total of 7/20 participants experienced grade 3-4 adverse events, while 17/20 participants completed the study. Of the 17 participants who completed the study, 8 remained suppressed during ATI, while all 17 were suppressed at end of treatment (EoT). As expected, treatment increased activation of T and natural killer (NK) cells and IFN-stimulated molecule expression on monocytes in periphery. While circulating CD4⁺ T cells showed a trend for a decrease in integrated HIV DNA, GALT showed a significant decrease in HIV-1 RNA⁺ cells as measured by in situ hybridization along with a reduction in total HIV DNA and cell-associated RNA by EoT. The observed decrease in HIV-1 RNA⁺ cells in GALT was positively associated with the decrease in activated NK cells and macrophages. This study documents for the first time that 20 weeks of immunotherapy with Peg-IFN-α2b+ART (inclusive of a 4-week ATI) is safe and results in an increase in blood and GALT immune activation and in a significant decrease in HIV-1 RNA⁺ cells in GALT in association with changes in innate cell activation.

Effect of new oral direct acting antiviral therapy on sexual function in male patients with hepatitis C virus

Hepatitis C virus (HCV) infection is a major health problem all over the world including Egypt. Chronic HCV infection is usually accompanied by decrease of libido and erectile dysfunction. This study aimed to evaluate the efficacy of new oral direct acting antiviral (DAA) therapy on sexual function of male patients with HCV. This study was conducted on 200 male participants divided into two groups, first group included 100 male patients with HCV and the second group included 100 healthy age matched males as a control. Patients received DAA for three months and virological free status was confirmed by polymerase chain reaction. All participants were subjected to full history taking, general examination and local genital examination, assessment of sexual function by a validated Arabic version of the international index of erectile function-5. Laboratory investigations included liver functions serum testosterone, free testosterone, sex hormone-binding globulin and bioavailable testosterone. Results of this study showed that patients with HCV suffer from sexual dysfunction than controls that significantly improved after DAA therapy, and this is accompanied by increasing of bioavailable testosterone. It could be concluded that beside its effectiveness in treatment of HCV infection, DAA therapy can improve sexual function in male patients with HCV.

Mathematical Modeling of MPNs Offers Understanding and Decision Support for Personalized Treatment

(1) Background: myeloproliferative neoplasms (MPNs) are slowly developing hematological cancers characterized by few driver mutations, with JAK2V617F being the most prevalent. (2) Methods: using mechanism-based mathematical modeling (MM) of hematopoietic stem cells, mutated hematopoietic stem cells, differentiated blood cells, and immune response along with longitudinal data from the randomized Danish DALIAH trial, we investigate the effect of the treatment of MPNs with interferon-α2 on disease progression. (3) Results: At the population level, the JAK2V617F allele burden is halved every 25 months. At the individual level, MM describes and predicts the JAK2V617F kinetics and leukocyte- and thrombocyte counts over time. The model estimates the patient-specific treatment duration, relapse time, and threshold dose for achieving a good response to treatment. (4) Conclusions: MM in concert with clinical data is an important supplement to understand and predict the disease progression and impact of interventions at the individual level.

Manipulation of autophagy for host-directed tuberculosis therapy

Mycobacterium tuberculosis (M. tb) is one of the world’s most successful human pathogens, infecting ~2 billion people worldwide. Although there are effective drugs against M. tb., the disease remains out of control owing to prolonged and toxic treatment. Shorter regimens are urgently required to control TB. Drug-resistant TB (DR-TB) also threatens to derail TB control. These unfulfilled needs could be addressed by the identification and development of host-directed therapeutic agents for TB. Manipulation of the innate immune response, including autophagy, may lead to the identification of cellular pathways that could be exploited to develop host-directed therapeutic interventions. Host-directed therapies (HDTs) aim to augment immune mechanisms against M. tb infection and/or reduce excess inflammation, thus preventing end-organ tissue damage, preserving lung function and/or enhancing the effectiveness of TB drug therapy in eliminating infection. HDTs may also have additional advantages for patients with TB/HIV co-infection, as HDTs may reduce the risk of interaction with antiretroviral drugs and the risk of developing immune reconstitution inflammatory syndrome (IRIS) and death. In this review, we discuss the role of autophagy as a potential pathway that could be exploited as a host-directed TB therapeutic agent.

Interferon Alpha 2a and 2b in Ophthalmology: A Review

Interferon alpha (IFN-α) is a glycoprotein with antitumor, antiviral, and immunomodulatory activity, used widely in the treatment of viral infections (hepatitis B and C, condylomata acuminata, herpes zoster, etc.), hematological disorders (leukemia, multiple myeloma, T cell lymphoma, and essential thrombocythemia), and solid tumors (clear cell carcinoma in the metastatic stage, melanoma, hepatocellular carcinoma, and cervical neoplasia). Studies have proven the effectiveness of IFN-α in the treatment of ophthalmic disorders involving the anterior segment of the eye (conjunctival papilloma, squamous neoplasia, conjunctival mucosa-associated lymphoid tissue, Mooren's ulcer, and vernal keratoconjunctivitis) and the posterior segment of the eye (serpiginous choroidopathy, posterior uveitis, pseudophakic and diabetic cystoid macular edema, and proliferative diabetic retinopathy). The therapy with IFN-α remains a promising alternative in cases of a failing response to conventional therapy, helping to maintain or improve visual acuity, prevent vision loss, and ameliorate the prognosis of the patient. However, clinicians who decide to use IFN-α in their patients must be aware of general and ophthalmological side effects and inform their patients to undergo a systemic evaluation such as a physical examination, blood and serological tests, and a chest X-ray before the beginning of treatment. This review presents the current knowledge of the use of IFN-α, its efficacy, and properties in ophthalmological diseases, and thus may encourage clinicians to administer this drug as a treatment modality in ophthalmological diseases in the future.

Comparison of Compliance and Efficacy of Pegylated Interferon α-2a and α-2b in Adults with Chronic Hepatitis C

This study compares treatment completion rates and outcomes in hepatitis C virus (HCV) patients between those aged <60 and ≥60 years receiving pegylated interferon (PEG-IFN) α-2a or α-2b combined with ribavirin. No significant differences were found in treatment completion rates and virological responses between age-stratified patients or between genotype-stratified patients receiving PEG-IFN α-2a versus PEG-IFN α-2b. Significantly more patients ≥60 years of receiving PEG-IFN α-2b exhibited an early virological response compared to those receiving PEG-IFN α-2a (P = 0.002); for patients <60 years of age, treatment outcomes were similar between the 2 groups. More liver fibrosis was observed in patients with HCV of genotype 1 than in those with genotypes 2 or 3. Mean changes in pre- and post-treatment fibrosis variables (bilirubin, platelet count, liver enzymes, FIB-4, and APRI) in HCV genotype 1 patients were greater in those receiving PEG-IFN α-2b than in those receiving PEG-IFN α-2a. Significant differences were not observed between age- and HCV genotype-stratified patients receiving PEG-IFN α-2a and -α-2b, but α-2b appears to have a modest efficacy advantage over α-2b, particularly in male HCV patients ≥60 years of age.

Peginterferon alfa-2a (40 kD) stopping rules in chronic hepatitis B: a systematic review and meta-analysis of individual participant data

BACKGROUND

Peginterferon alfa-2a (PEG-IFN) treatment stopping rules in chronic hepatitis B (CHB) are clinically desirable. Previous studies exploring this topic contained important limitations resulting in inconsistent recommendations within the current treatment guidelines. We undertook a systematic review and individual patient data meta-analysis to identify the most appropriate PEG-IFN treatment stopping rules.

METHODS

Roche's internal database, PubMed and conference abstracts were searched for studies that enrolled >50 treatment-naive patients with CHB who received PEG-IFN treatment for 48 weeks. Stopping rules were identified using receiver-operating characteristic curve analyses and pre-specified biomarker cutoff target performance characteristics (sensitivity >95%, specificity >10%, negative predictive value >90%). Robustness of proposed stopping rules was assessed using internal/external validation analyses.

RESULTS

Eight study datasets were included in the meta-analysis (n=1,423; 765 hepatitis B e antigen [HBeAg]-positive, 658 HBeAg-negative patients). In general, performance of hepatitis B surface antigen (HBsAg) and HBV DNA cutoffs at weeks 12 and 24 was similar, and common biomarker cutoffs that met target performance criteria were identified across multiple patient subgroups. For HBeAg-positive genotype B/C and HBeAg-negative genotype D patients the proposed stopping rule is HBsAg >20,000 IU/ml at week 12. Alternatively, HBV DNA level cutoffs of >8 log₁₀ and >6.5 log₁₀ IU/ml, respectively, can be used instead. The proposed stopping rules accurately identify up to 26% of non-responders.

CONCLUSIONS

The meta-analysis demonstrates that early PEG-IFN discontinuation should be considered in HBeAg-positive genotype B/C and HBeAg-negative genotype D patients at week 12 of treatment based on HBsAg or HBV DNA levels.

Human interferon-ϵ and interferon-κ exhibit low potency and low affinity for cell-surface IFNAR and the poxvirus antagonist B18R

IFNϵ and IFNκ are interferons that induce microbial immunity at mucosal surfaces and in the skin. They are members of the type-I interferon (IFN) family, which consists of 16 different IFNs, that all signal through the common IFNAR1/IFNAR2 receptor complex. Although IFNϵ and IFNκ have unique expression and functional properties, their biophysical properties have not been extensively studied. In this report, we describe the expression, purification, and characterization of recombinant human IFNϵ and IFNκ. In cellular assays, IFNϵ and IFNκ exhibit ∼1000-fold lower potency than IFNα2 and IFNω. The reduced potency of IFNϵ and IFNκ are consistent with their weak affinity for the IFNAR2 receptor chain. Despite reduced IFNAR2-binding affinities, IFNϵ and IFNκ exhibit affinities for the IFNAR1 chain that are similar to other IFN subtypes. As observed for cellular IFNAR2 receptor, the poxvirus antagonist, B18R, also exhibits reduced affinity for IFNϵ and IFNκ, relative to the other IFNs. Taken together, our data suggest IFNϵ and IFNκ are specialized IFNs that have evolved to weakly bind to the IFNAR2 chain, which allows innate protection of the mucosa and skin and limits neutralization of IFNϵ and IFNκ biological activities by viral IFN antagonists.

Telementoring of primary care providers delivering hepatitis C treatment in New York City: Results from Project INSPIRE

INTRODUCTION

The recent availability of highly effective, easily administered, and relatively nontoxic treatments for hepatitis C virus (HCV) infection provides an opportunity for clinicians to treat HCV in nonspecialist settings with appropriate support. Project INSPIRE provides care coordination to HCV patients and a web-based training program (telementoring) on disease management and treatment by HCV specialists to primary care providers inexperienced in HCV treatment. Weekly telementoring sessions use a didactic and case-based approach to instruct non-HCV providers on how to identify and assess HCV treatment candidates and prescribe appropriate treatment.

METHODS

We used mixed methods to assess the telementoring service, including provider surveys and semistructured interviews. Quantitative data were analyzed using descriptive statistics, and qualitative data were analyzed to identify dominant themes.

RESULTS

Provider survey responses indicated an increased ability to identify and evaluate HCV treatment candidates and increased confidence in sharing knowledge with peers and patients. Interviews revealed a high degree of satisfaction with the telementoring service and Project INSPIRE overall. The telementoring service was viewed as having enhanced providers' knowledge, confidence, and ability to treat their own HCV-infected patients rather than having to refer them to an HCV specialist with resulting benefits for continuity of care. Providers reported comradery and collegiality with other INSPIRE providers and satisfaction with professional growth from attaining new knowledge and skills via the telementoring service.

CONCLUSIONS

Using readily available web conferencing technology, telementoring can facilitate knowledge transfer between specialists and primary care providers, facilitating continuity of care for patients and increased provider satisfaction.

Elimination half-lives of interleukin-6 and cytokine-induced neutrophil chemoattractant-1 synthesized in response to inflammatory stimulation in rats

The elimination half-lives of in Interleukin-6 (IL-6) and cytokine-induced neutrophil chemoattractant-1 (CINC-1) in rats after inflammatory stimulation were investigated. Five male Sprague-Dawley rats were used (age, 9 weeks; body weight, 235-375 g). Turpentine oil was intramuscularly injected at a dose of 2 mL/kg body weight to induce acute inflammation. Blood was collected pre-injection and 6, 12, 24, 36, 48, 60, 72, 84, and 96 h after the turpentine oil injection. Serum concentrations of IL-6, CINC-1, and α2-macroglobulin (α2M) were measured by enzyme-linked immunosorbent assay. Half-lives were calculated as 0.693/elimination rate constant. The serum concentration of α2M peaked at 48 h after turpentine oil injection. Serum concentrations of IL-6 and CINC-1 increased and peaked at 12 and 24 h, respectively. The terminal elimination half-lives of IL-6 and CINC-1 were 15.5 and 29.9 h, respectively. The half-life of CINC-1 was significantly longer than that of IL-6 (P=0.006). These results suggested that these cytokines synthesized in response to inflammatory stimulation were rapidly eliminated in rats. The serum concentrations of these cytokines should be measured at an early stage if these cytokines will be used as surrogate inflammatory markers instead of acute-phase proteins.

Intrapatient viral diversity and treatment outcome in patients with genotype 3a hepatitis C virus infection on sofosbuvir-containing regimens

Treatment with the direct-acting antiviral agent (DAA) sofosbuvir (SOF), an NS5B inhibitor, and velpatasvir (VEL), an NS5A inhibitor, demonstrates viral cure rates of ≥95% in hepatitis C virus (HCV) genotypes (GT) 1-6. Here, we investigated intrapatient HCV diversity in NS5A and NS5B using Shannon entropy to examine the relationship between viral diversity and treatment outcome. At baseline, HCV diversity was lowest in patients infected with HCV GT3 as compared to the other GTs, and viral diversity was greater in NS5A than NS5B (P < .0001). Treatment outcome with SOF/VEL or the comparator regimen of SOF with ribavirin (RBV) was not correlated with baseline diversity. However, among persons treated with SOF/VEL, a decrease in diversity from baseline was observed at relapse in the majority virologic failures, consistent with a viral bottleneck event at relapse. In contrast, an increase in diversity was observed in 27% of SOF+RBV virologic failures. We investigated whether the increase in diversity was due to an increase in the transition rate, one mode of potential RBV-mediated mutagenesis; however, we found no evidence of this mechanism. Overall, we did not observe that viral diversity at baseline influenced treatment outcome, but the diversity changes observed at relapse can improve our understanding of RBV viral suppression in vivo.

Pharmacokinetics comparison of two pegylated interferon alfa formulations in healthy volunteers

BACKGROUND

Several countries have used pegylation technology to improve the pharmacokinetic properties of essential drugs. Recently, a novel interferon alfa-2b protein conjugated to four-branched 12 kDa polyethylene glycol molecules was developed jointly between Cuba and Brazil. The aim of this study was to compare the pharmacokinetic properties of BIP48 (pegylated interferon alfa-2b from Bio-Manguinhos/Fiocruz, Brazil) to those of PEGASYS® (commercially available pegylated interferon alfa-2a from Roche Pharmaceutical).

METHODS

This phase I, single-centre, randomized, double-blind crossover trial enrolled 31 healthy male volunteers aged 19 to 35 who were allocated to two stages, either side of a 5-week wash-out period, with each arm lasting 14 consecutive days after subcutaneous administration of 180 μg of one formulation or the other (study or comparator). The main outcome variable was serum pegylated interferon concentrations in 15 samples collected during the course of the study and tested using an enzyme immunoassay.

RESULTS

There were no differences between formulations in terms of magnitude or absorption parameters. Analysis of time parameters revealed that BIP48 remained in the body significantly longer than PEGASYS® (Tmax: 73 vs. 54 h [p = 0.0010]; MRT: 133 vs. 115 h [p = 0.0324]; ke: 0.011 vs. 0.013 h(-1) [p = 0.0153]; t1/2: 192 vs. 108 h [p = 0.0218]).

CONCLUSION

BIP48 showed the expected pharmacokinetic profile for a pegylated product with a branched molecular structure. Compared to PEGASYS®, the magnitude absorption was similar, but time parameters were consistent with slower elimination. Further studies should be conducted to evaluate the clinical implications of these findings. A phase II-III repeated-dose clinical trial is ongoing to study these findings in patients with chronic hepatitis C virus infection.

TRIAL REGISTRATION

This study is registered on the ClinicalTrials.gov platform (accession number NCT01889849 ). This trial was retrospectively registered in June 2013.

In Vivo SELEX of an Inhibitory NSCLC-Specific RNA Aptamer from PEGylated RNA Library

Aptamers are widely used in numerous biochemical, bioanalytical, and biological studies. Most aptamers are developed through an in vitro selection process called SELEX against either purified targets or living cells expressing targets of interest. We report here an in vivo SELEX in mice using a PEGylated RNA library for the identification of a 2'-F RNA aptamer (RA16) that specifically binds to NCI-H460 non-small-cell lung cancer cells with an affinity (K_D) of 9 ± 2 nM. Interestingly, RA16 potently inhibited cancer cell proliferation in a dose-dependent manner with an IC₅₀ of 116.7 nM. When tested in vivo in xenografted mice, RA16 showed gradual migration toward tumor and accumulation at tumor site over time. An in vivo anti-cancer study showed that the average inhibition rate for mouse tumors in the RA16-treated group was 54.26% ± 5.87% on day 16 versus the control group. The aptamer RA16 adducted with epirubicin (RA16-epirubicin) showed significantly higher toxicity against targeted NCI-H460 cells and low toxicity against non-targeted tumor cells. Furthermore, RA16-epirubicin adduct exhibited in vivo anti-cancer efficacy, with an inhibition rate of 64.38% ± 7.92% when administrated in H460 xenograft mouse model. In summary, a specific bi-functional RNA aptamer RA16 was selected targeting and inhibiting toward NCI-H460 in vitro and in vivo.

Polymer-Based Protein Engineering: Synthesis and Characterization of Armored, High Graft Density Polymer-Protein Conjugates

Atom transfer radical polymerization (ATRP) from the surface of a protein can generate remarkably dense polymer shells that serve as armor and rationally tune protein function. Using straightforward chemistry, it is possible to covalently couple or display multiple small molecule initiators onto a protein surface. The chemistry is fine-tuned to be sequence specific (if one desires a single targeted site) at controlled density. Once the initiator is anchored on the protein surface, ATRP is used to grow polymers on protein surface, in situ. The technique is so powerful that a single-protein polymer conjugate molecule can contain more than 90% polymer coating by weight. If desired, stimuli-responsive polymers can be "grown" from the initiated sites to prepare enzyme conjugates that respond to external triggers such as temperature or pH, while still maintaining enzyme activity and stability. Herein, we focus mainly on the synthesis of chymotrypsin-polymer conjugates. Control of the number of covalently coupled initiator sites by changing the stoichiometric ratio between enzyme and the initiator during the synthesis of protein-initiator complexes allowed fine-tuning of the grafting density. For example, very high grafting density chymotrypsin conjugates were prepared from protein-initiator complexes to grow the temperature-responsive polymers, poly(N-isopropylacrylamide), and poly[N,N'-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate]. Controlled growth of polymers from protein surfaces enables one to predictably manipulate enzyme kinetics and stability without the need for molecular biology-dependent mutagenesis.

Hepatitis C virus infection in maintenance hemodialysis patients: recommendations for diagnostics and treatment

Hepatitis C virus (HCV) infection is highly prevalent among patients treated with maintenance hemodialysis and is an important cause of morbidity and mortality. It is necessary to determine the HCV genotype and the viral load to monitor the clinical and laboratory features and to establish an optimal antiviral treatment strategy. Antiviral treatments are presented with a standard interferon-based regimen and new direct-acting antiviral agents. The advent of direct-acting antivirals has improved the efficacy and safety of HCV treatment for most patients, even in difficult-to-treat populations such as patients on hemodialysis. HCV treatment with direct-acting antivirals in hemodialysis patients is highly effective, with viral eradication rates similar to those seen in patients without chronic kidney disease and with acceptable adverse event profiles.

Treatment-emergent depression and anxiety between peginterferon alpha-2a versus alpha-2b plus ribavirin for chronic hepatitis C

BACKGROUND

This study investigates differences in depression and anxiety between patients with chronic hepatitis C who are treated with peginterferon alpha-2a (PegIFN-α-2a) plus ribavirin and those who are treated with peginterferon alpha-2b (PegIFN-α-2b) plus ribavirin.

METHODS

In this 24 week, non-randomized, observational, prospective study, 55 patients with chronic hepatitis C were treated with PegIFN-α-2a plus ribavirin (Group 1), and 26 patients were treated with PegIFN-α-2b plus ribavirin (Group 2). All patients underwent assessment using the Hospital Anxiety and Depression Scale (HADS) at the baseline and at weeks 4, 12 and 24. Patients with depression scores (HADS-D) ≥ 8 and anxiety scores (HADS-A) ≥ 8 were defined as having depression and anxiety, respectively. The factors that were associated with depression and anxiety during the 24 week antiviral treatment were determined.

RESULTS

During the 24 week antiviral treatment, the proportion of patients with depression significantly increased over time in both groups (Group 1: p = 0.048; Group 2: p = 0.044). The proportion of patients with anxiety did not significantly change during the follow-up period in either group. Incidences of depression or anxiety did not differ significantly between Group 1 and Group 2. A history of alcohol use disorder was an independent predictor of depression at week 12 (p < 0.001) and week 24 (p < 0.001), and a poor virological response to treatment was associated with depression at week 24 (p = 0.029). Patients who had more physical comorbidities were more likely to suffer from anxiety at week 12 (p = 0.038).

CONCLUSIONS

This study did not identify significant differences in depression or anxiety between in patients with chronic hepatitis C who underwent a 24 week antiviral treatment regimen with PegIFN-α-2a plus ribavirin and those who underwent a regiment with PegIFN-α-2b plus ribavirin. Future research with larger samples and a randomized, controlled design are required to verify the findings in this study.

TRIAL REGISTRATION

This clinical study has been registered at ClinicalTrials.gov. (Trial registration: NCT02943330 ).

Galactosylated Lipidoid Nanoparticles for Delivery of Small Interfering RNA to Inhibit Hepatitis C Viral Replication In Vivo

Small interfering RNA (siRNA) delivery can provide an effective therapy for treating viral diseases by silencing genes involved in viral replication. In this study, a liver-targeting formulation of lipidoid nanoparticle for delivery of siRNA that targets protein kinase C-related kinase 2 (PRK2) to inhibit hepatitis C virus (HCV) replication is reported. The most effective, minimally cytotoxic lipidoid for siRNA delivery to hepatic cells is identified from a small library of alkyl epoxide-polyamine conjugates. In vitro transfection of PRK2 siRNA (siPRK2) using this lipidoid induces significant silencing of PRK2 (≈80%), suppressing HCV replication in human hepatic cells transfected with the HCV subgenomic replicon. Systemic administration of siPRK2 using the lipidoid nanoparticles results in significant reduction of host PRK2 in the mouse liver (≈60%). This treatment significantly suppresses HCV replication in an HCV-xenograft mouse model. siRNA delivery to the liver is further improved via galactosylation of the lipidoid. Compared with the unmodified lipidoid formulation, galactosylated lipidoids induce greater silencing of host PRK2 in mouse livers (≈80%) and more rapid suppression of HCV replication in an HCV-xenograft mouse. This study suggests that galactosylated lipidoid nanoparticles could provide a treatment for hepatitis C by mediating delivery of anti-viral RNA interference therapeutics to the liver.

Host-directed therapies for infectious diseases: current status, recent progress, and future prospects

Despite extensive global efforts in the fight against killer infectious diseases, they still cause one in four deaths worldwide and are important causes of long-term functional disability arising from tissue damage. The continuing epidemics of tuberculosis, HIV, malaria, and influenza, and the emergence of novel zoonotic pathogens represent major clinical management challenges worldwide. Newer approaches to improving treatment outcomes are needed to reduce the high morbidity and mortality caused by infectious diseases. Recent insights into pathogen–host interactions, pathogenesis, inflammatory pathways, and the host's innate and acquired immune responses are leading to identification and development of a wide range of host-directed therapies with different mechanisms of action. Host-directed therapeutic strategies are now becoming viable adjuncts to standard antimicrobial treatment. Host-directed therapies include commonly used drugs for non-communicable diseases with good safety profiles, immunomodulatory agents, biologics (eg monoclonal antibodies), nutritional products, and cellular therapy using the patient's own immune or bone marrow mesenchymal stromal cells. We discuss clinically relevant examples of progress in identifying host-directed therapies as adjunct treatment options for bacterial, viral, and parasitic infectious diseases.

Anti-Viral Therapy and Decreased Sexual Desire in Patients with Chronic Hepatitis C

Purpose

Peg-interferon (PegIFN)α2a or PegIFNα2b plus ribavirin (RBV) is the standard therapy for chronic hepatitis C virus (HCV) infection in Taiwan and Asia. It is commonly associated with adverse effects, but the issue of sexual and mental health is not well reported. This study aimed to evaluate the impact of anti-viral therapy with PegIFNα plus RBV on sexual desire and depression.

Methods

This prospective cohort study from 2009 to 2014 enrolled 181 patients with HCV who received PegIFNα2a (180 mcg/week) or PegIFNα2b (1.5 mcg/Kg/week) plus RBV (800–1200 mg/day) according to response-guide therapy for 24 to 48 weeks in a tertiary medical center. Patients with decreased sexual desire (DSD) before PegIFNα plus RBV were excluded. Patients were evaluated at baseline (week 0) and after 2, 4, 8, 12, 16, 20, and 24 weeks of PegIFNα plus RBV treatment using the structured Mini-International Neuropsychiatric Interview, for the diagnosis of a major depressive episode, and the 21-item Beck Depression Inventory (BDI), for monitoring depressive symptoms. The 21st item of the BDI was used to evaluate DSD.

Results

During therapy, 124 (68.5%) patients had DSD. The BDI score peaked at 14.8 weeks. The severity of DSD was greatest at 16 weeks of treatment. The average score of the 21st item of the BDI correlated with DSD. Depression history and the prevalence of subsequent major depressive disorder after anti-viral therapy was correlated to DSD (p = 0.05 and 0.001). Male patients complained of DSD more significantly than females (p = 0.031).

Conclusions

Decreased sexual desire is common but is usually neglected in patients with chronic hepatitis C undergoing anti-viral therapy, especially among male patients. Physicians must be monitoring the side effects of sexual health and depression.

Current views on interferon therapy for HIV

INTRODUCTION

Knowledge of IFN-antiviral activity against HIV infection dates from the first years of the AIDS epidemic. Recombinant IFN had an inhibitory effect on HIV and was not toxic to peripheral blood mononuclear cells (PBMC), and this finding was the basis for the design of clinical trials that evaluated the potential role of IFN-alpha as an inhibitor of HIV replication.

AREAS COVERED

This review summarizes the history of IFN-alpha in the treatment of HIV infection with reviews of studies performed in different clinical settings; in the pre-highly active antiretroviral therapy (HAART) era, as part of a structured treatment interruption (STI) strategy, in acute HIV infection, as part of salvage therapy, and eliminating the HIV reservoir.

EXPERT OPINION

The role of IFN-alpha has been dismissed in the area of HIV therapy. For this reason, with the advent of HAART, which substantially reduced mortality and the appearance of AIDS, IFN-alpha ceased to be used as an antiretroviral agent in different strategies. In contrast, because of the promising results achieved with IFN-alpha therapy in eliminating the HIV viral reservoir, this may constitute the main research field for IFN-alpha in the HIV setting.

Predictors of Virological Response in 3,235 Chronic HCV Egyptian Patients Treated with Peginterferon Alpha-2a Compared with Peginterferon Alpha-2b Using Statistical Methods and Data Mining Techniques

Despite the appearance of new oral antiviral drugs, pegylated interferon (PEG-IFN)/RBV may remain the standard of care therapy for some time, and several viral and host factors are reported to be correlated with therapeutic effects. This study aimed to reveal the independent variables associated with failure of sustained virological response (SVR) to PEG-IFN alpha-2a versus PEG-IFN alpha-2b in treatment of naive chronic hepatitis C virus (HCV) Egyptian patients using both statistical methods and data mining techniques. This retrospective cohort study included 3,235 chronic hepatitis C patients enrolled in a large Egyptian medical center: 1,728 patients had been treated with PEG-IFN alpha-2a plus ribavirin (RBV) and 1,507 patients with PEG-IFN alpha-2b plus RBV between 2007 and 2011. Both multivariate analysis and Reduced Error Pruning Tree (REPTree)-based model were used to reveal the independent variables associated with treatment response. In both treatment types, alpha-fetoprotein (AFP) >10 ng/mL and HCV viremia >600 × 10(3) IU/mL were the independent baseline variables associated with failure of SVR, while male gender, decreased hemoglobin, and thyroid-stimulating hormone were the independent variables associated with good response (P < 0.05). Using REPTree-based model showed that low AFP was the factor of initial split (best predictor) of response for either PEG-IFN alpha-2a or PEG-IFN alpha-2b (cutoff value 8.53, 4.89 ng/mL, AUROC = 0.68 and 0.61, P = 0.05). Serum AFP >10 ng/mL and viral load >600 × 10(3) IU/mL are variables associated with failure of response in both treatment types. REPTree-based model could be used to assess predictors of response.

Development and application of a fast, reproducible assay to measure HCV NS3 protease activity using Escherichia coli lysate

The hepatitis C virus (HCV) NS3/4A protease is a key target of efforts to develop direct-acting antiviral inhibitors for treatment of chronic HCV infection. In vitro analyses of the effects of NS3/4A mutations and polymorphisms on protease inhibitor (PI) susceptibility are essential to nonclinical and clinical compound characterization, but can be hampered by time and technical limitations of current in vitro methods using replicon or purified protein systems. We have developed a fast and simple method utilizing full-length NS3/4A protease inducibly expressed in Escherichia coli cells. Minimally processed E. coli whole cell lysate was used for analyzing NS3/4A protease activity and inhibition by antiviral compounds. Assay conditions were optimized to develop a reproducible assay that can be used for efficient analysis of NS3 protease mutants with poor replication capacity in the replicon system. IC50 fold-changes for NS3 mutants relative to their wild-types generated by this NS3 assay are comparable to those observed in the replicon system, with an R(2) of 0.82 for the values obtained by the two methods. In addition, we demonstrate that this assay can be successfully used for population and clonal phenotyping of patient samples and characterization of PIs against the NS3/4A protease from HCV genotypes 1-6.

PEGylation and its impact on the design of new protein-based medicines

PEGylation is the covalent conjugation of PEG to therapeutic molecules. Protein PEGylation is a clinically proven approach for extending the circulation half-life and reducing the immunogenicity of protein therapeutics. Most clinically used PEGylated proteins are heterogeneous mixtures of PEG positional isomers conjugated to different residues on the protein main chain. Current research is focused to reduce product heterogeneity and to preserve bioactivity. Recent advances and possible future directions in PEGylation are described in this review. So far protein PEGylation has yielded more than 10 marketed products and in view of the lack of equally successful alternatives to extend the circulation half-life of proteins, PEGylation will still play a major role in drug delivery for many years to come.

Immune-modulators to combat hepatitis B virus infection: From IFN-α to novel investigational immunotherapeutic strategies

Chronic hepatitis B virus (HBV) infection remains a major challenge for clinicians, as there are only two types of approved therapies: interferon-alpha (IFN-α) or its pegylated form, Peg-IFN-α and nucleoside analogs (e.g. tenofovir, entecavir...). The first are used as finite-duration treatments of around 48-52 weeks, while the second must be taken life-long to prevent rebound. Other immune-modulators, including other types of recombinant IFNs and cytokines/chemokines, could be developed for treating chronic hepatitis B. Alternatively, strategies aimed either at restoring or favoring the endogenous production of IFNs, cytokines and/or chemokines, or at alleviating HBV-mediated inhibitory processes could also be envisaged. In this article, we review current investigational, preclinical and clinical efforts to implement immune-modulatory components in the therapy of chronic hepatitis B. This review forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B".

Severe immune thrombocytopenia after peg-interferon-alpha2a, ribavirin and telaprevir treatment completion: A case report and systematic review of literature

Mild to moderate autoimmune thrombocytopenia (AITP) is a common finding in patients receiving interferon-based antiviral treatment, due to bone marrow suppression. Here we report the case of a patient with chronic genotype 1b hepatitis C virus (HCV) infection treated with pegylated-interferon alpha-2a, ribavirin and telaprevir for 24 wk; the patient developed severe AITP three weeks after treatment withdrawal. We performed a systematic literature search in order to review all published cases of AITP related to HCV antiviral treatment. To our knowledge, this is the second case of AITP observed after antiviral treatment withdrawal. In most published cases AITP occurred during treatment; in fact, among 24 cases of AITP related to interferon-based antiviral treatment, only one occurred after discontinuation. Early diagnosis of AITP is a key factor in order to achieve an early interferon discontinuation; in the era of new direct antiviral agents those patients have to be considered for interferon-free treatment regimens. Prompt prescription of immuno-suppressant treatment (i.e., corticosteroids, immunoglobulin infusion and even rituximab for unresponsive cases) leads to favourable prognosis in most of cases. Physicians using interferon-based treatments should be aware that AITP can occur both during and after treatment, specially in the new era of interferon-free antiviral treatment. Finally, in the case of suspected AITP, presence of anti-platelet antibodies should be checked not only during treatment but also after discontinuation.

Drug-Drug Interactions Among Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV) Medications

One-fourth of individuals diagnosed with the human immunodeficiency virus concomitantly have the hepatitis C virus infection. Since the discovery of highly active antiretroviral therapy, liver complications have become the leading cause of morbidity and mortality in HIV-HCV coinfected individuals. Optimal treatment in this patient population is critical, as coinfection has been linked to deterioration of both disease states. The objective of this review article is to highlight the current literature on drug-drug interactions between HIV and HCV treatments. The management of the treatment of coinfection patients has been covered extensively in numerous other publications.

Study of pruritus in chronic hepatitis C patients

AIM: To investigate the occurrence and severity of pruritus in chronic hepatitis C patients treated with or without interferon (IFN) therapy.

METHODS: A total of 89 patients with chronic hepatitis C and 55 control (non-hepatitis) patients were asked to rate their experience of diurnal and nocturnal pruritus in the preceding week using a visual analogue scale (VAS) and a five-point scale, respectively. Blood samples were taken and serum thymus and activation-regulated chemokine (TARC) levels were measured by enzyme-linked immunosorbent assay.

RESULTS: A significantly greater proportion of chronic hepatitis C patients experienced nocturnal pruritus compared with control (58.4% vs 5.5%, P < 0.0001). Chronic hepatitis C patients also had more severe pruritus compared with control patients, indicated by the higher mean VAS scores in both the IFN-treated and non-IFN-treated groups. In particular, patients who received combined peginterferon alfa-2b and ribavirin had significantly higher mean VAS scores than those receiving peginterferon alfa-2a or no IFN treatment. Serum TARC levels did not correlate with pruritus scores, and no significant differences in TARC levels were observed between the IFN-treated and non-IFN-treated groups.

CONCLUSION: Patients with chronic hepatitis C experience pruritus more than those without. Serum TARC levels do not correlate with pruritus severity in chronic hepatitis C patients.

Peginterferon alfa-2a is associated with elevations in alanine aminotransferase at the end of treatment in chronic hepatitis C patients with sustained virologic response

Background

The purpose of this study was to investigate the incidence and demographic/clinical factors of alanine aminotransferase (ALT) abnormalities at the end of treatment (EOT) in chronic hepatitis C (CHC) patients with sustained virologic response (SVR).

Methods and Findings

Seven hundred naïve CHC patients who underwent combination treatment between January 2003 and December 2010 were included in the study. The patients with SVR and serum ALT>upper limit of normal (ULN) at the EOT were further analyzed. The effects of clinical characteristics, treatment regimen, and virologic variables were evaluated by logistic regression. Of the 700 included patients, 488 (69.7%) achieved an SVR after treatment, and 235 (33.6%) had serum ALT levels>ULN at the EOT. Of those 488 patients, 137 (28.1%) had abnormal ALT values at the EOT. A multivariate analysis showed that the occurrence of ALT abnormalities at the EOT was significantly associated with pegylated interferon (PEG-IFN) alfa-2a (odds ratio [OR], 2.24; 95% confidence interval [CI], 1.45–3.45; P<0.001), baseline fatty liver (OR, 1.76; 95% CI, 1.16–2.76; P = 0.007), and baseline liver cirrhosis (OR, 2.35; 95% CI, 1.35–4.09; P = 0.002).

Conclusions

Use of PEG-IFN-alfa-2a, fatty liver, and cirrhosis are important factors associated with EOT-ALT abnormality in CHC patients receiving combination therapy that achieve an SVR. PEG-IFN-alfa-2a-related EOT-ALT elevation will become normal at the end of follow-up, but fatty liver and cirrhosis-related ALT elevation will not be resolved.

Detection of anti-cytokine antibodies and their clinical relevance

Cytokines regulate many aspects of cell growth and differentiation and play pivotal roles in the orchestration of immune defence against invading pathogens. Though 'self' proteins, they are potentially immunogenic and can give rise to anti-cytokine autoantibodies (aCA). The main foci of the article are a critical summary of the various methodologies applied for detecting and measuring aCA and a broad review of studies of the occurrence, characterization and clinical relevance of aCA in normal healthy individuals, patients with autoimmune diseases or microbial infections and aCA in patients whose disease is treated with recombinant cytokine products. The need for technical and methodological improvement of assays, including validation and standardization, together with approaches to harmonize calculation and reporting of results is also discussed.

Pegylated IFN-α regulates hepatic gene expression through transient Jak/STAT activation

The use of pegylated interferon-α (pegIFN-α) has replaced unmodified recombinant IFN-α for the treatment of chronic viral hepatitis. While the superior antiviral efficacy of pegIFN-α is generally attributed to improved pharmacokinetic properties, the pharmacodynamic effects of pegIFN-α in the liver have not been studied. Here, we analyzed pegIFN-α-induced signaling and gene regulation in paired liver biopsies obtained prior to treatment and during the first week following pegIFN-α injection in 18 patients with chronic hepatitis C. Despite sustained high concentrations of pegIFN-α in serum, the Jak/STAT pathway was activated in hepatocytes only on the first day after pegIFN-α administration. Evaluation of liver biopsies revealed that pegIFN-α induces hundreds of genes that can be classified into four clusters based on different temporal expression profiles. In all clusters, gene transcription was mainly driven by IFN-stimulated gene factor 3 (ISGF3). Compared with conventional IFN-α therapy, pegIFN-α induced a broader spectrum of gene expression, including many genes involved in cellular immunity. IFN-induced secondary transcription factors did not result in additional waves of gene expression. Our data indicate that the superior antiviral efficacy of pegIFN-α is not the result of prolonged Jak/STAT pathway activation in hepatocytes, but rather is due to induction of additional genes that are involved in cellular immune responses.

A new reagent for stable thiol-specific conjugation

Many clinically used protein therapeutics are modified to increase their efficacy. Example modifications include the conjugation of cytotoxic drugs to monoclonal antibodies or poly(ethylene glycol) (PEG) to proteins and peptides. Monothiol-specific conjugation can be efficient and is often accomplished using maleimide-based reagents. However, maleimide derived conjugates are known to be susceptible to exchange reactions with endogenous proteins. To address this limitation in stability, we have developed PEG-mono-sulfone 3, which is a latently reactive, monothiol selective conjugation reagent. Comparative reactions with PEG-maleimide and other common thiol-selective PEGylation reagents including vinyl sulfone, acrylate, and halo-acetamides show that PEG-mono-sulfone 3 undergoes more efficient conjugation under mild reaction conditions. Due to the latent reactivity of PEG-mono-sulfone 3, its reactivity can be tailored and, once conjugated, the electron-withdrawing ketone is easily reduced under mild conditions to prevent undesirable deconjugation and exchange reactions from occurring. We describe a comparative stability study demonstrating a PEG-maleimide conjugate to be more labile to deconjugation than the corresponding conjugate obtained using PEG-mono-sulfone 3.

The antiviral activity of poly-γ-glutamic acid, a polypeptide secreted by Bacillus sp., through induction of CD14-dependent type I interferon responses

Poly-γ-glutamic acid (γ-PGA) is an anionic polypeptide secreted by Bacillus sp. that has been shown to activate immune cells through interactions with toll-like receptor 4 (TLR4). However, its ability to induce the type I interferon (IFN) response has not yet been characterized. Here, we demonstrate that γ-PGA induces type I IFN signaling pathway via the TLR4 signaling pathway. The induction required both myeloid differentiation factor 2 (MD2) and the pattern-recognition receptor CD14, which are two TLR4-associated accessory proteins. The γ-PGA with high molecular weights (2000 and 5000 kDa) was able to activate the subsequent signals through TLR4/MD2 to result in dimerization of IRF-3, a transcription factor required for IFN gene expression, leading to increases in mRNA levels of the type I IFN-response genes, 2′–5′ OAS and ISG56. Moreover, γ-PGA (2000 kDa) displayed an antiviral activity against SARS coronavirus and hepatitis C virus. Our results identify high-molecular weight γ-PGA as a TLR4 ligand and demonstrate that γ-PGA requires both CD14 and MD2 for the activation of type I IFN responses. Our results suggest that the microbial biopolymer γ-PGA may have therapeutic potential against a broad range of viruses sensitive to type I IFNs.

Pegylated interferon-α2a and ribavirin versus pegylated interferon-α2b and ribavirin in chronic hepatitis C : a meta-analysis

INTRODUCTION

Results of trials and meta-analyses comparing pegylated interferon (PEG-IFN)-α2a and PEG-IFN-α2b for the treatment of chronic hepatitis C are conflicting.

OBJECTIVE

Our objective was to determine which PEG-IFN (α2a or α2b), in association with ribavirin, is the most effective for the treatment of chronic hepatitis C by performing an updated meta-analysis.

METHOD

MEDLINE (1950-2012) and EMBASE (1974-2012) databases, as well as the Cochrane Central Register of controlled trials and the Cochrane Database of Systematic Reviews, were searched. Reference lists of retrieved articles were scanned, and proceedings of major international conferences were manually searched for abstracts. Randomized clinical trials and non-randomized clinical studies comparing PEG-IFN-α2a with PEG-IFN-α2b in association with ribavirin in adult patients with chronic hepatitis C were included. Studies including HIV-positive patients or liver transplant recipients were excluded. The data extraction from each study was conducted independently by two authors, with disagreements resolved by consensus or by a third reviewer. The trial quality of randomized clinical trials was assessed by taking into account generation of allocation sequence, allocation concealment, efficacy of randomization, investigator blindness, description of withdrawals and dropouts and adherence to the intention-to-treat principle. Two meta-analyses were performed, the first including randomized clinical trials only, and the second including both randomized and non-randomized clinical studies. The primary outcome measure was frequency of sustained virological response (SVR). Heterogeneity and publication bias were systematically taken into account.

RESULTS

This meta-analysis included 26 studies, 11 randomized and 15 non-randomized, with a total of 18,260 patients: 8,125 treated with PEG-IFN-α2a and 10,135 treated with PEG-IFN-α2b. In the meta-analysis that included randomized trials only, the SVR was significantly higher for patients treated with PEG-IFN-α2a than for those treated with PEG-IFN-α2b for genotypes 1 and 4 [odds ratio (OR) 1.45; 95 % CI 1.09-2.06; p = 0.013] and for all genotypes (OR 1.34; 95 % CI 1.05-1.72; p = 0.02). In the meta-analysis including both randomized and non-randomized studies, the SVR was significantly higher for PEG-IFN-α2a than for PEG-IFN-α2b for all genotypes (OR 1.24; 95 % CI 1.10-1.40; p < 0.001) and for genotypes 1 and 4 (OR 1.25; 95 % CI 1.14-1.36; p < 0.001); for genotypes 2 and 3, the SVR was greater for treatment with PEG-IFN-α2a than with PEG-IFN-α2b, with the difference tending towards significance (OR 1.15; 95 % CI 0.98-1.35; p = 0.08). A certain degree of heterogeneity was present amongst the various studies included in this meta-analysis. Publication bias was detected (particularly for analyses including only randomized controlled trials) and taken into account using appropriate statistical methods.

CONCLUSION

Current evidence suggests that PEG-IFN-α2a and ribavirin is associated with a higher SVR than PEG-IFN-α2b and ribavirin in patients mono-infected with hepatitis C, particularly for genotypes 1 and 4.