Hepatic histologic response (HR) to combination therapy among HCV/HIV-coinfected individuals: interferon induces HR independent of sustained virologic response (SVR)

Inteleukin-23 promotes interferon-α responsiveness in hepatitis C virus/HIV-coinfected patients

Patients coinfected with HIV and hepatitis C virus (HCV) have poor to modest rates of response with interferon-based therapies, which remain a backbone of the treatment in HIV/HCV-coinfected patients. The mechanisms responsible for poor responsiveness to interferon are not well described. In this study a targeted proteomic analysis of plasma from 42 patients infected with both HIV and HCV and undergoing therapy for HCV with peginterferon and ribavirin was performed. Higher baseline plasma levels of interleukin (IL)-23 were associated with sustained virologic response. Further investigation of how IL-23 facilitates interferon (IFN) responsiveness, as evidenced by a >2-fold increase in most interferon-stimulated genes (ISGs), revealed that IL-23 indirectly enhances IFN signaling in peripheral blood mononuclear cells and HCV continuous culture system by preventing the down-regulation of the IFNAR2 receptor after exposure to IFN-α. These findings suggest a unique role of the IL-23 pathway in enhancing host response to type I interferons, thereby facilitating eradication of HCV. Low levels of IL-23 present in plasma of nonresponders may reflect an impaired immune state that in the case of HIV/HCV-coinfected subjects could potentially lead to disruption of TH17 CD4(+) T cells. This study suggests a major role for HIV-associated immune dysregulation present in HIV-infected subjects that subsequently determines the overall responsiveness to exogenous interferon-α-based HCV therapy.

Histologic outcomes in hepatitis C-infected patients with varying degrees of virologic response to interferon-based treatments

Patients with chronic hepatitis C with partial virologic response or nonresponse to interferon-based therapies can experience treatment-related improvements in liver histology. This retrospective analysis assessed the histologic response to treatment in patients with varying degrees of virologic response (sustained virologic response [SVR], breakthrough, relapse, or nonresponse), time to hepatitis C virus (HCV) RNA undetectability, and duration of viral suppression. Patients (HCV genotypes 1-6) with baseline and follow-up liver biopsies from eight phase 2 to phase 4 interferon-based trials were analyzed. Blinded biopsies were evaluated by a single pathologist. Improvements or worsening of METAVIR necroinflammatory activity and fibrosis were defined as increase or decrease of ≥1 grading category from baseline to 24 weeks after end of treatment. A majority of the 1571 patients with paired biopsy data were white, male, with HCV genotype 1/4, baseline HCV RNA levels >800,000 IU/mL, and baseline alanine aminotransferase levels ≤3 × upper limit of the normal range; mean baseline activity and fibrosis scores were 1.8 and 1.7, respectively. Overall, 80% of patients received peginterferon alfa-2a monotherapy or peginterferon alfa-2a/ribavirin combination therapy. Mean treatment duration was 46 weeks. There was a positive correlation between the degree of virologic response and improvements in METAVIR activity and fibrosis, and an inverse correlation with worsening activity and fibrosis (all comparisons, P < 0.0001). Patients with SVR had the greatest histologic benefit. As a combined group, relapsers and patients with breakthrough had significantly greater benefits than nonresponders (activity, P = 0.0001; fibrosis, P = 0.003). Consistent with these results, a better histologic response was correlated with a shorter time to undetectable HCV RNA and a longer duration of viral suppression (all comparisons, P < 0.0001).

CONCLUSION

In patients with chronic hepatitis C who were treated with interferon-based therapies, histologic benefits may be observed even in the absence of an SVR.

Hepatitis C viral kinetics during treatment with peg IFN-alpha-2b in HIV/HCV coinfected patients as a function of baseline CD4+ T-cell counts

BACKGROUND

HIV/hepatitis C virus (HCV) coinfected patients are known to have lower sustained viral response (SVR) rates than HCV monoinfected patients. However, the role of CD4+ T-cell counts on viral kinetics and outcome is not fully understood.

METHODS

HCV RNA kinetics (bDNA v3, lower limit of detection [LD] = 615 IU/mL) was analyzed in 32 HIV/HCV coinfected persons treated with Pegylated-interferon-alpha2b (1.5 microg/kg weekly) and ribavirin (1-1.2 g daily) for 48 weeks and compared with results obtained from 12 HCV monoinfected patients treated with the same regimen.

RESULTS

Baseline CD4+ T-cell counts > or =450 cells/mm3 were significantly (P < 0.002) associated with SVR in coinfected genotype 1 patients. First phase decline was significantly lower among patients with low as compared with high CD4 counts (P < 0.03) and among coinfected compared with monoinfected patients (P < 0.002). Second phase decline slope showed a similar trend for coinfected patients.

CONCLUSIONS

Low baseline CD4+ T-cell count is associated with slower HCV viral kinetics and worse response to treatment among HIV coinfected patients, suggesting HCV treatment response depends on immune status. HCV genotype 1 coinfected patients have slower first phase viral kinetics than HCV monoinfected patients. First phase viral decline (>1.0 log) and second phase viral decline slope (>0.3 log/wk) are excellent predictors of SVR for coinfected patients.

Pegylated IFN-alpha2b plus ribavirin for treatment-naive patients coinfected with HCV and HIV

Since 1995, after the generalization of highly active antiretroviral therapy (HAART), HCV coinfection in patients with HIV has become a clinical problem of first magnitude. In fact, currently, HCV coinfection is the primary cause of morbi-mortality of AIDS patients in many hospitals. As a consequence, a significant number of clinical trials have been carried out during the past 8-10 years on HCV/HIV-coinfected patients, and have been coincident that the use of pegylated interferon (PEG-IFN) plus ribavirin should be now the gold standard for treating these patients. Various prospective, randomized studies have reached the conclusion that PEG-IFN-alpha(2b) plus ribavirin achieves HCV cure rates in approximately 50% of all patients, together with important clinical consequences, since hepatic illness progression stops or even reverts. Although adverse events are extremely common with this combined treatment, it is also true that their handling by experts means that only 10-15% of patients must abandon treatment.