Clinical experiences with interferon as monotherapy or in combination with ribavirin in patients co-infected with HIV and HCV

Barriers to hepatitis C antiviral therapy in HIV/HCV co-infected patients in the United States: a review

This review synthesized the literature for barriers to HCV antiviral treatment in persons with HIV/HCV co-infection. Searches of PubMed, Embase, CINAHL, and Web of Science were conducted to identify relevant articles. Articles were excluded based on the following criteria: study conducted outside of the United States, not original research, pediatric study population, experimental study design, non-HIV or non-HCV study population, and article published in a language other than English. Sixteen studies met criteria and varied widely in terms of study setting and design. Hepatic decompensation was the most commonly documented absolute/nonmodifiable medical barrier. Substance use was widely reported as a relative/modifiable medical barrier. Patient-level barriers included nonadherence to medical care, refusal of therapy, and social circumstances. Provider-level barriers included provider inexperience with antiviral treatment and/or reluctance of providers to refer patients for treatment. There are many ongoing challenges that are unique to managing this patient population effectively. Documenting and evaluating these obstacles are critical steps to managing and caring for these individuals in the future. In order to improve uptake of HCV therapy in persons with HIV/HCV co-infection, it is essential that barriers, both new and ongoing, are addressed, otherwise, treatment is of little benefit.

Haematological support during peg-interferon therapy for HCV-infected haemophiliacs improves virological outcomes

Hepatitis C virus-infected haemophiliacs are traditionally under represented in international treatment studies thus data assessing response to pegylated-interferon (peg-IFN) and ribavirin (RBV) in HCV mono-infected or HCV/HIV co-infected haemophiliacs are few. Since 2001, 37 haemophiliac patients have received peg-IFN and RBV according to centre-based investigator initiated protocols. Primary end points were: early virological response (EVR); end of treatment response (EOTR) and sustained virological response (SVR). An intention-to-treat analysis was used. Secondary end points were adverse events, haemopoietic stem cell growth factor use, therapy discontinuations and dose reductions. Hepatitis C virus mono-infection group (Mono-I) numbered 20 (60% genotype 1). HCV/HIV co-infected group (Co-I) numbered 17 (59% genotype 1/4). Primary end points were: EVR 76%, EOTR 70% and SVR 43%. Comparison of Mono-I to Co-I demonstrated: EVR rates of 70% and 82%, respectively; EOTR rates of 65% and 76%, respectively, and SVR rates of 35% and 53%, respectively. SVR rates genotype 1/4 group - 17% (Mono-I) vs. 30% (Co-I); SVR rates genotype 2/3 group - 63% (Mono-I) vs. 86% (Co-I). Therapy discontinuations: six of 20 (30%) Mono-I vs. three of 17 (18%) Co-I. Dose reductions: two of 20 (10%) Mono-I vs. zero of 17 Co-I. Haematological support factor use: one of 20 (5%) Mono-I vs. four of 17 (23.5%) Co-I. Virological outcomes to peg-IFN and RBV in HCV-infected haemophiliacs are comparable to published data relating to other HCV-infected cohorts. Good virological outcomes can be achieved in HIV co-infected haemophiliacs particularly when growth factors are used to facilitate full dosing of peg-IFN and RBV.

Antiviral therapy for chronic hepatitis C in patients with inherited bleeding disorders: an international, multicenter cohort study

BACKGROUND

Hepatitis C is a major co-morbidity in patients with hemophilia. However, there is little information on the efficacy of antiviral therapy and long-term follow-up after treatment.

OBJECTIVES

To assess the effect of interferon-based (IFN-based) therapy on hepatitis C virus (HCV) eradication, to identify determinants associated with treatment response, and to assess the occurrence of end-stage liver disease (ESLD) after completing antiviral therapy.

PATIENTS AND METHODS

In a multicenter cohort study, 295 treatment-naïve hemophilia patients chronically infected with HCV were included. The effect of therapy was expressed as sustained virological response (SVR). Determinants associated with treatment response were expressed as odds ratios (ORs). Cumulative incidence of ESLD was assessed using a Kaplan-Meier survival table.

RESULTS

Among human immunodeficiency virus (HIV) negative patients (n = 235), SVR was 29% (29/101) for IFN monotherapy, 44% (32/72) for IFN with ribavirin, and 63% (39/62) for pegylated IFN (PegIFN) with ribavirin. In patients co-infected with HIV (n = 60), IFN monotherapy, IFN with ribavirin, and PegIFN with ribavirin eradicated HCV in 7/35 (20%), 1/2 (50%), and 11/23 (48%), respectively. SVR increased with genotype 2 and 3 [OR 11.0, 95% CI: 5.8-20.5], and combination therapy (IFN and ribavirin OR 3.7, 95% CI: 1.7-8.4), PegIFN and ribavirin (OR 4.2, 95% CI: 1.8-9.5). Up to 15 years after antiviral treatment, none of the patients with a SVR relapsed and none developed ESLD. In contrast, among unsuccessfully treated patients the cumulative incidence of ESLD after 15 years was 13.0%.

CONCLUSIONS

Successful antiviral therapy appears to have a durable effect and reduces the risk of ESLD considerably.

Treatment of chronic hepatitis C in patients with haemophilia: a review of the literature

Chronic hepatitis C is a major cause of morbidity and mortality in haemophilia patients. In contrast to studies in the general population, the studies of antiviral therapy in haemophilia patients are limited and often include small numbers of patients. A review of the literature was performed to assess the efficacy of interferon (IFN)-based therapy for patients with haemophilia chronically infected with hepatitis C virus (HCV). Studies were identified by electronic searches (Medline, Embase) and hand searches in references of key articles. Data of the included studies were pooled, and responses to therapy were stratified according to treatment regimen, HIV co-infection status, and treatment history. The main outcome was a sustained virological response (SVR) defined as absence of HCV RNA both at the end of treatment and 24-week post-treatment. Thirty-five studies were identified that included 1151 patients. After pooling the data of included patients, the SVR in HIV-negative treatment naïve patients was 22% for IFN monotherapy, 43% for IFN and ribavirin, and 57% for pegylated IFN and ribavirin, respectively. Re-treatment with IFN and ribavirin of those who failed to respond to previous IFN monotherapy was successful in 33%. In HCV/HIV-coinfected patients, response to IFN monotherapy was 8% and to IFN combined with ribavirin 39%. Responses to IFN-based therapy in patients with haemophilia have been improved over time and are nowadays approximately 50-60%. However, data on haemophilic HCV/HIV-coinfected patients and in patients who failed to respond to previous therapy are limited and future studies in these specific patient population are necessary.

Use of liposomal anthracyclines in Kaposi’s sarcoma

Conventional chemotherapy regimens for the treatment of advanced Kaposi's sarcoma (KS) show limited efficacy and considerable toxicity. Liposomal anthracyclines with potential utility in KS include pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]), daunorubicin citrate liposome (DaunoXome [DNX]), and nonpegylated liposomal doxorubicin (Myocet [NPLD]). Preclinical data showed that pegylated liposomes accumulate preferentially in highly vascularized KS lesions. In randomized clinical trials, PLD induced higher response rates than did the conventional combination chemotherapy regimens, bleomycin + vincristine (BV) and BV + conventional doxorubicin (ABV); DNX produced a response rate comparable to that of ABV. NPLD has not been compared with conventional chemotherapy for KS. PLD and DNX were associated with less toxicity compared with BV or ABV, including less alopecia and fewer gastrointestinal and neurologic side effects. Grade 3/4 myelosuppression was common with both PLD and DNX; stomatitis and infusion reactions occurred with PLD treatment, but hand-foot syndrome was relatively infrequent in the dose schedules used for KS. Health-related quality of life was improved in several domains in patients treated with PLD or DNX compared with ABV.

Hepatitis C-HIV coinfection: current and future therapy

Coinfection with hepatitis C in HIV-infected patients has been reported in 15-70% of patients depending on the mode of acquisition of both viruses. As recent advances in HIV-directed antiviral therapy have markedly delayed HIV progression and mortality, the incidence of complications arising from hepatitis C-associated liver disease in coinfected patients is increasing exponentially. The interaction of HIV and hepatitis C is complex. It is clear that HIV infection negatively affects the natural history of hepatitis C, while HIV-directed therapy may enhance immunologic response and exacerbate hepatocellular injury induced by hepatitis C via immune reconstitution. In this review, the pathobiology, inter-relation of hepatitis C and HIV infection in coinfected patients as well as present and future treatment in this unique patient population are discussed.

Hepatitis C virus (HCV) relapses after anti-HCV therapy are more frequent in HIV-infected patients

The response to standard or pegylated interferon (IFN) plus ribavirin (RBV) seems to be lower in hepatitis C virus (HCV)/HIV-coinfected subjects than in HCV-monoinfected patients. Thus, the principles guiding anti-HCV therapy in HIV-negative patients may not apply in the setting of HIV infection. We examined the rate of HCV relapse in 58 HCV/HIV-coinfected subjects who showed undetectable HCV-RNA (<600 IU/ml) at the end of anti-HCV combination therapy. Overall, 19 (32.8%) patients relapsed after discontinuing treatment, a rate significantly higher than that seen in HIV negatives, which is in the range of 15-20%. There were no significant differences between HCV genotypes (33.3% for HCV genotypes 2-3 versus 31.8% for HCV genotypes 1-4) and/or the use of either standard or pegylated IFN (37% versus 29%, respectively). Thus, extended periods of anti-HCV therapy might reduce HCV relapses in HIV-coinfected patients initially responding to therapy.

Dendritic cells mediate NK cell help for Th1 and CTL responses: two-signal requirement for the induction of NK cell helper function

Early stages of viral infections are associated with local recruitment and activation of dendritic cells (DC) and NK cells. Although activated DC and NK cells are known to support each other's functions, it is less clear whether their local interaction in infected tissues can modulate the subsequent ability of migrating DC to induce T cell responses in draining lymph nodes. In this study, we report that NK cells are capable of inducing stable type 1-polarized "effector/memory" DC (DC1) that act as carriers of NK cell-derived helper signals for the development of type 1 immune responses. NK cell-induced DC1 show a strongly elevated ability to produce IL-12p70 after subsequent CD40 ligand stimulation. NK-induced DC1 prime naive CD4+ Th cells for high levels of IFN-gamma, but low IL-4 production, and demonstrate a strongly enhanced ability to induce Ag-specific CD8+ T cell responses. Resting NK cells display stringent activation requirements to perform this novel, DC-mediated, "helper" function. Although their interaction with K562 cells results in effective target cell killing, the induction of DC1 requires a second NK cell-activating signal. Such costimulatory signal can be provided by type I IFNs, common mediators of antiviral responses. Therefore, in addition to their cytolytic function, NK cells also have immunoregulatory activity, induced under more stringent conditions. The currently demonstrated helper activity of NK cells may support the development of Th1- and CTL-dominated type 1 immunity against intracellular pathogens and may have implications for cancer immunotherapy.

Serum Interferon Inhibitor Declines in Patients with HIV‐1 Infection After a Change in Antiretroviral Therapy

An inhibitor of interferon antiviral activity, which is absent in healthy HIV-seronegative persons, was detected in the sera of all 29 HIV-seropositive study participants. The relationship of the level of interferon inhibitor to CD4 count and HIV-RNA copy number was statistically significant in distinct models. Levels of interferon inhibitor declined by an average of 41-60% in patients who underwent a change in anti-retroviral therapy. Interferon inhibitor levels appear to decline as CD4 cell count rises and HIV-RNA levels fall. This suggests that interferon inhibitor may have a significant role in the host immune response to HIV infection.

Pretreatment of chronic active hepatitis C in patients coinfected with HIV and hepatitis C virus reduces the hepatotoxicity associated with subsequent antiretroviral therapy

Chronic hepatitis C virus (HCV) is an independent risk factor for antiretroviral-related hepatotoxicity, but little is known about the frequency of severe liver toxicity in patients with HIV-HCV coinfection first treated for HCV (pretreated). The aim of this prospective study of 105 patients was to compare the incidence of progression to severe antiretroviral-related liver toxicity in 66 patients pretreated (36 with interferon-alpha [IFNalpha], 30 with IFNalpha plus ribavirin), and 39 patients not pretreated. The subjects could choose whether to receive anti-HCV therapy. Severe liver toxicity was defined as alanine aminotransferase (ALT) level > or =5-times the upper limit of normal in patients with normal baseline levels and > or =3.5-times in those with increased baseline levels. The authors also estimated the hepatotoxicity-related risk of discontinuing antiretroviral therapy. During antiretroviral therapy, 10 subjects (9.5%) experienced severe hepatotoxicity: 4 of 66 pretreated patients and 6 of 39 untreated patients (24-month survival: 94% +/- 2.9% vs. 85% +/- 5.8%). After adjusting for baseline CD4 cell counts, ALT levels, histologic scores, HCV and HIV viremia, HCV genotype (genotype 1 in 29% of pretreated patients and 20% of patients not pretreated), and previous anti-HCV therapy, the risk of discontinuing anti-HIV treatment was significantly higher in the anti-HCV untreated patients (RR = 10.4; 95% CI: 1.6-66; p =.0127) and in those with increased baseline ALT levels (RR = 1.014; 95% CI: 1.006-1.021; p =.0005). The authors' data suggest that previous treatment of chronic active HCV is an independent factor associated with a decrease of severe liver toxicity as the result of a subsequent antiretroviral regimen. The authors also confirm that the baseline level of ALT is an important prognostic factor for increased liver damage during antiretroviral therapy.

Pegylated IFN-alpha2b plus ribavirin as therapy for chronic hepatitis C in HIV-infected patients

BACKGROUND

Treatment of hepatitis C virus (HCV) has become a major challenge in HIV-infected individuals. No data exist on the efficacy and tolerability of pegylated IFN (peg-IFN) plus ribavirin in HIV-co-infected patients.

METHODS

Subcutaneous peg-IFN (150 microg weekly during the first 12 weeks and 100 microg weekly thereafter) plus ribavirin (400 mg twice a day) was given to 68 HIV-infected patients with chronic hepatitis C, having CD4 cell counts greater than 300 cells/microl, plasma HIV-RNA less than 5000 copies/ml, and elevated aminotransferase levels. All were naive for IFN, and 73% were receiving antiretroviral drugs.

RESULTS

Plasma HCV-RNA levels greater than 800 000 IU/ml were seen in 50%, and 35% carried HCV genotype 3. Adverse events leading to treatment discontinuation occurred in 10 patients (15%). One patient taking didanosine developed pancreatitis. Severe weight loss occurred in 70% of patients. Clearance of HCV-RNA at the end of therapy (6 months for HCV-3 and 12 months for HCV-1/4) occurred in 50% of patients (81% with HCV-3 versus 30% with HCV-1/4). As 30% relapsed, the overall sustained response rate was 35% (28% in the intent-to-treat analysis). The main predictors of response were infection with HCV-3 and low HCV load.

CONCLUSION

Treatment with peg-IFN and ribavirin is relatively well-tolerated in HIV/HCV-co-infected patients, although new side-effects, including pancreatitis and severe weight loss, may result from the interaction of ribavirin with antiretroviral drugs. Overall, therapy provides cure to one third of patients, a rate significantly lower than that seen in HCV-monoinfected individuals. Given that relapses are common, extended periods of therapy should be investigated.