T. Santantonio

Possible mechanism involving T-lymphocyte response to non-structural protein 3 in viral clearance in acute hepatitis C virus infection

In acute hepatitis C virus (HCV) infection only 20-50% of patients spontaneously clear the virus. To characterise the immune reaction during that phase we studied the response of peripheral blood mononuclear cells (PBMC) to the recombinant HCV proteins core, non-structural protein 3 (NS3), NS4, and NS5 in 14 patients with acute hepatitis C. All eight patients with self-limited disease compared with two of six with evolving chronic infection showed an NS3- specific PBMC response (p = 0.015). Of 65 patients with established chronic hepatitis C, five showed a PBMC response to NS3. NS3-specific CD4 T-cell clones from patients with self-limited infection predominantly produced interferon-gamma and may thus support cytotoxic effector mechanisms important for viral clearance.

Recurrence of hepatitis C virus after loss of virus-specific CD4(+) T-cell response in acute hepatitis C

BACKGROUND & AIMS The prospective comparison of patients with acute hepatitis C virus (HCV) who spontaneously clear the virus with those who cannot achieve viral elimination and progress to chronic hepatitis offers the unique opportunity to analyze natural mechanisms of viral elimination. METHODS We studied the HCV-specific CD4(+) T-cell response in 38 patients with acute HCV and correlated the clinical course with the antiviral immune response. The individual HCV-specific T-cell response was assessed in a proliferation assay ((3)H-thymidine uptake) and an enzyme-linked immunospot assay. RESULTS Patients were classified according to their clinical course and pattern of CD4(+) T-cell responses in 3 categories: first, patients mounting a strong and sustained antiviral CD4(+)/Th1(+) T-cell response who cleared the virus (HCV RNA-negative; n = 20); second, patients who were unable to mount an HCV-specific CD4(+) T-cell response and developed chronic disease (n = 12); and third, patients who initially displayed a strong CD4(+) T-cell response and eliminated the virus (HCV PCR-negative) but subsequently lost this specific T-cell response (n = 6). The loss of the HCV-specific CD4(+) T-cell response was promptly followed by HCV recurrence. CONCLUSIONS The results indicate that a virus-specific CD4(+)/Th1(+) T-cell response that eliminates the virus during the acute phase of disease has to be maintained permanently to achieve long-term control of the virus. The induction and/or maintenance of virus-specific CD4(+) T cells could represent a promising therapeutic approach in HCV infection.

Sustained virological response to interferon-α is associated with improved outcome in HCV-related cirrhosis: A retrospective study†‡

The effect of achieving a sustained virological response (SVR) following interferon‐α (IFNα) treatment on the clinical outcomes of patients with HCV‐related cirrhosis is unknown. In an attempt to assess the risk of liver‐related complications, HCC and liver‐related mortality in patients with cirrhosis according to the response to IFNα treatment, a retrospective database was developed including all consecutive patients with HCV‐related, histologically proven cirrhosis treated with IFNα monotherapy between January 1992 and December 1997. SVR was an undetectable serum HCV‐RNA by PCR 24 weeks after IFNα discontinuation. HCC was assessed by ultrasound every 6 months. Independent predictors of all outcomes were assessed by Cox regression analysis. Of 920 patients, 124 (13.5%) were classified as achieving a SVR. During a mean follow‐up of 96.1 months (range: 6‐167) the incidence rates per 100 person‐years of liver‐related complications, HCC and liver‐related death were 0, 0.66, and 0.19 among SVR and 1.88, 2.10, and 1.44 among non‐SVR (P < 0.001 by log‐rank test). Multivariate analyses found that non‐SVR was associated with a higher risk of liver‐related complications (hazard ratio, HR, not applicable), HCC (HR 2.59; 95% CI 1.13‐5.97) and liver‐related mortality (HR 6.97; 95% CI 1.71‐28.42) as compared to SVR. Conclusion: Thus, in patients with HCV‐related, histologically proven cirrhosis, achievement of a SVR after IFNα therapy was associated with a reduction of liver‐related mortality lowering both the risk of complications and HCC development. Irrespective of SVR achievement, all patients should continue surveillance because the risk of occurrence of HCC was not entirely avoided. (HEPATOLOGY 2007;45:579–587.)

Association of Hepatitis C Virus—Specific CD8+ T Cells with Viral Clearance in Acute Hepatitis C

CD8+ T lymphocytes play a major role in antiviral immune defense. Their significance for acute hepatitis C is unclear. Our aim was to correlate the CD8+ T cell response with the outcome of infection. Eighteen patients with acute hepatitis C and 19 normal donors were studied. Hepatitis C virus (HCV)-specific CD8+ T cells were identified in the enzyme-linked immunospot assay by their interferon-gamma (IFN-gamma) production after specific stimulation. The highest numbers of IFN-gamma-producing HCV-specific CD8+ T cells were found in patients with acute hepatitis C and a self-limited course of disease during the first 6 months after onset of disease, but these numbers dropped thereafter to undetectable levels. The differences in responsiveness between patients with self-limited disease versus patients with a chronic course were statistically significant (P<.001). Our data show that the number of IFN-gamma-producing HCV-specific CD8+ T cells during the first 6 months after onset of disease is associated with eradication of the HCV infection.

CD8 + T lymphocyte responses are induced during acute hepatitis C virus infection but are not sustained

Cellular immune responses are likely to play a key role in determining the clinical outcome in acute infection with hepatitis C virus (HCV), but the dynamics of such responses and their relationship to viral clearance are poorly understood. In a previous study we have shown highly activated, multispecific cytotoxic T lymphocyte responses arising early and persisting in an individual who subsequently cleared the virus. In this study the HCV‐specific CD8+ lymphocytes response has been similarly analyzed, using peptide‐HLA class I tetramers, in a further nine individuals with documented acute HCV infection, six of whom failed to clear the virus. Significant populations of virus‐specific CD8+ lymphocytes were detected at the peak of acute hepatic illness (maximally 3.5 % of CD8+ lymphocytes). Frequencies were commonly lower than those seen previously and were generally not sustained. Early HCV‐specific CD8+ lymphocytes showed an activated phenotype in all patients (CD38+ and HLA class II+), but this activation was short‐lived. Failure to sustain sufficient numbers of activated virus‐specific CD8+ lymphocytes may contribute to persistence of HCV.

Long-term follow-up of patients with anti-HBe/HBV DNA-positive chronic hepatitis B treated for 12 months with lamivudine

BACKGROUND/AIMS Interferon alpha provides benefit in only a limited number of patients with chronic anti-HBe-positive hepatitis B. The aim of this study was to verify the long-term efficacy of lamivudine treatment of these patients and the incidence of lamivudine-resistant hepatitis B virus mutants. METHODS Fifteen consecutive patients with chronic anti-HBe-positive hepatitis B were treated with lamivudine 100 mg once daily for 52 weeks. Levels of alanine aminotransferase, HBV DNA, hepatitis B surface antigen, and IgM antibodies to hepatitis B core antigen were monitored during therapy and 12-month follow up. The polymerase gene was amplified by polymerase chain reaction and the region coding for YMDD amino acid motif was directly sequenced. RESULTS Only 2/15 patients (13%) had a sustained virological and biochemical response and improved histologically. Eleven out of 15 (74%) showed inhibition of viral replication and normalization of alanine aminotransferase levels during lamivudine treatment but relapsed 1-12 months after terminating therapy. In the two remaining patients (13%), HBV DNA initially became negative but reappeared in the serum after 24 weeks, and in both patients the emergence of YMDD mutants was demonstrated. CONCLUSIONS Our data confirm the antiviral efficacy of lamivudine in anti-HBe-positive patients, but response to a 1-year course was only transient as the majority of patients relapsed after therapy withdrawal. The lack of a sustained effect and the emergence of lamivudine-resistant mutants suggest that therapy for chronic hepatitis B should be based on a combination of several therapeutic agents.

Entecavir treatment for chronic hepatitis B: Adaptation is not needed for the majority of naïve patients with a partial virological response†‡

Entecavir (ETV) is a potent inhibitor of viral replication in nucleos(t)ide analogue (NA)‐naïve chronic hepatitis B (CHB) patients. The aim of this study was to investigate the long term efficacy and safety of ETV in NA‐naïve CHB patients, particularly in those with detectable hepatitis B virus (HBV) DNA after 48 weeks, in whom treatment adaptation is suggested by current guidelines. In a multicenter cohort study, we investigated 333 CHB patients treated with entecavir monotherapy. The NA‐naïve population consisted of 243 patients, whereas 90 were NA‐experienced. Virological response (VR) (HBV DNA <80 IU/mL) was achieved in 48%, 76%, and 90% of hepatitis B e antigen (HBeAg)‐positive and in 89%, 98%, and 99% of HBeAg‐negative NA‐naïve patients at weeks 48, 96, and 144, respectively. Thirty‐six of 175 (21%) NA‐naïve patients with at least 48 weeks of follow‐up had a detectable load at week 48 (partial virological response [PVR]). Twenty‐nine (81%) patients with PVR reached VR during prolonged ETV monotherapy, and none of them developed ETV‐resistance. Among 22 patients with HBV DNA <1,000 IU/mL at week 48, VR was achieved in 21 (95%) patients, compared with eight of 14 (57%) patients with HBV DNA ≥1,000 IU/mL. Continuous HBV DNA decline was observed in most patients without VR during follow‐up, and in three patients adherence was suboptimal according to the treating physician. ETV was safe and did not affect renal function or cause lactic acidosis. Conclusion: ETV monotherapy can be continued in NA‐naïve patients with detectable HBV DNA at week 48, particularly in those with a low viral load because long‐term ETV leads to a virological response in the vast majority of patients. (HEPATOLOGY 2011;)

Anti-HBe-positive chronic hepatitis B with HBV-DNA in the serum response to a 6-month course of lymphoblastoid interferon

Eighteen heterosexual HBsAg carriers with anti-HBe- and HBV-DNA-positive chronic hepatitis B (CHB) were randomly assigned to receive human lymphoblastoid interferon (ly-IFN) at a dose of 5 MU/m2 i.m. three times a week for 6 months (ten cases) or no treatment (eight cases). All patients were followed for 24 months after IFN discontinuation and received a second liver biopsy. During the 6 months of treatment all patients had a progressive reduction of serum HBV-DNA levels, and at the end of therapy nine out of ten were HBV-DNA-negative and had normal ALT values. None of the untreated patients became persistently HBV-DNA-negative or showed significant variations of ALT levels. During the post-treatment follow-up, from 1 to 17 months after ly-IFN discontinuation, eight of the nine responders (89%) had recurrent or persistent reappearance of HBV-DNA in the serum and reactivation of the liver disease activity, with an ALT peak in four of them. On the post-trial liver biopsy seven of the eight relapsed patients showed persistence of HBcAg reactivity with no significant difference in the percentage of positive cells with respect to the pre-treatment liver specimen. Histological features improved in four treated patients, worsened in one untreated case and were unchanged in the remaining patients. These results indicate that ly-IFN shows a transient antiviral effect in the therapy of anti-HBe- and HBV-DNA-positive CHB. The 6-month treatment regimen employed in this study seems insufficient for eradicating the replicating virus from the liver cells in the majority of patients and consequently does not appear to prevent HBV reactivation after IFN discontinuation.

Acute hepatitis C: Current status and remaining challenges

The acute phase of hepatitis C virus (HCV) infection represents a key point in the evolution of hepatitis C. In some patients, the infection resolves spontaneously, whereas in others it develops into chronic disease. However, because acute hepatitis C is often asymptomatic, detection and diagnosis are usually difficult. What is more, there are no established treatment guidelines, leaving physicians to make several challenging decisions, such as whether to treat, when to treat and what treatment regimen to use. Pegylated interferon alfa monotherapy is most commonly used to treat patients with acute hepatitis C; the role of ribavirin has yet to be established. In this review, we discuss the epidemiology of acute hepatitis C, its risk factors and routes of transmission and current treatment practices. We also discuss data from published clinical studies and focus on unresolved issues for which additional studies are needed in order to establish standardized treatment guidelines for the management of acute hepatitis C.

Plasmacytoid dendritic cells in acute and chronic hepatitis C virus infection

Chronic evolution of acute hepatitis C (aHC) occurs in more than 80% of patients but can frequently be prevented by early treatment with interferon (IFN)‐α. Plasmacytoid dendritic cells (pDCs) are the major endogenous IFN‐α producers, but their role in aHC is unknown. In this study, frequency, phenotype, and pDC function were analyzed in 13 patients with aHC and 32 patients with chronic hepatitis C (cHC) compared with 20 healthy controls, 33 sustained responders to antiviral treatment, 14 patients with acute hepatitis B (aHB), and 21 patients with nonviral inflammatory disease. In aHC, pDCs in the peripheral blood were significantly reduced compared with healthy controls (median, 0.1% vs. 0.36%, P < .0005) and were inversely correlated to alanine aminotransferase levels (r = −0.823; P < .005). Circulating pDCs in aHC were immature, as determined via reduced expression of HLA‐DR and CCR7, and produced little amounts of IFN‐α (median, 3.5 pg/50,000 peripheral blood mononuclear cells [PBMCs] vs. 498.4 pg/50,000 PBMCs in healthy controls; P < .0005). Less pronounced changes were present in cHC (median, 0.17%, 28.0 pg/50,000 PBMCs IFN‐α, respectively). However, a significantly reduced frequency and IFN‐α production was also found in self‐limited aHB (median 0.1%, 8.6 pg/50,000 PBMCs) and in patients with nonviral inflammatory disease (median 0.19%, 7.5 pg/50,000 PBMCs). In conclusion, in aHC frequency and IFN‐α–producing capacity of peripheral blood pDCs are dramatically reduced and inversely correlated with the degree of liver inflammation. In cHC there is incomplete recovery of pDC function, which, however, could be solely due to the chronic inflammatory state. (HEPATOLOGY 2005;41:643–651.)