Factors predictive of response to interferon-alpha therapy in hepatitis C virus type 1b infection

Interferon-alpha (IFN-alpha) has been used to treat hepatitis C Virus (HCV)-induced infection but has been effective in only about half of all patients. It is suggested that the different responses to IFN-alpha treatment in HCV infection may be influenced by HCV genotypes, HCV RNA titer at the beginning of IFN-alpha therapy, and the sequences of the interferon sensitivity determining region (ISDR). However, there have also been reports showing that these have no relation to an IFN-alpha effect. In a previous study, it was found that the nucleotide sequence variation in the hypervariable region (HVR) 1 of the HCV could predict the effect of IFN-alpha. In the present investigation, an attempt was made to determine the predictive factors of IFN-alpha therapy. Twenty-six patients with HCV infection were treated with IFN-alpha. Among these, 13 patients recovered after 3 to 6 months of IFN-alpha treatment, although the other 13 patients showed no response after 6 months of treatment with IFN-alpha. In order to determine the predictive factors of IFN-alpha therapy, the ALT levels, HCV genotypes, HCV serum titer, and the quasispecies of HVR 1 were compared between responders and non-responders. It is suggested that the variation in the HVR 1 and HCV serum titer can be used to predict the effect of IFN-alpha.     

Oligoclonal CD8+ T-Cell Expansion in Patients with Chronic Hepatitis C Is Associated with Liver Pathology and Poor Response to Interferon-α Therapy

The role of CD8(+) T lymphocytes in chronic hepatitis C virus (HCV) infection and in liver injury with subsequent development of fibrosis and cirrhosis is poorly understood. To address this question, we performed a follow-up study including 27 chronically HCV-infected individuals. We determined clonality and phenotypes of circulating CD8(+) T cells employing TCRBV spectratyping. Antigen specificity was tested by rMHC-peptide tetramer staining and stimulation with recombinant HCV antigens. In addition, T-cell clonality and phenotypes were followed during the variable clinical response of interferon- (IFN) alpha treatment. We could demonstrate that CD8(+) T-cell expansions were significantly associated with liver fibrosis and cirrhosis. Likewise, increased oligoclonality of circulating CD8(+) T cells in chronic HCV infection was identified as an indicator for poor clinical response to IFN-alpha therapy. Moreover, we also found that IFN-alpha therapy enhanced the differentiation of CD8(+) T cells towards a late differentiation phenotype (CD28(-) CD57(+)). In cases of virus elimination the disappearance of expanded terminally differentiated CD8(+) cells was observed. Thus, this study identifies an association of clonal expansions of circulating CD8(+) T cells with liver pathology and provides a possible explanation for the fact that response to IFN-alpha therapy diminishes with the duration of infection.     

High prevalence of hypervariable region 1-specific and -cross-reactive CD4(+) T cells in HCV-infected individuals responsive to IFN-alpha treatment

The hypervariable region 1 (HVR1) of the putative envelope 2 protein of the hepatitis C virus (HCV) is the most variable part of the whole HCV polyprotein. Anti-HVR1 antibodies have been shown to protect against HCV infection, indicating that this region contains an important neutralization determinant. Recently we and others have demonstrated that HVR1 is also a T cell determinant able to activate helper T cell responses during HCV infection. In order to investigate the role of the immune response against HVR1 during HCV infection we have evaluated the humoral and lymphoproliferative responses to a panel of HVR1 peptides in HCV-infected patients with different outcomes of the disease following interferon-alpha (IFN-alpha) treatment. We observed that the frequency of anti-HVR1 T cell responses was significantly higher in patients who recovered after IFN-alpha therapy than in those who did not, while no differences in the anti-HVR1 antibody reactivities were detected. In addition, by generating HVR1-specific T cell lines and clones we identified human leukocyte-associated antigens DR4 restricted T cell epitopes in the carboxy-terminus of HVR1 and we demonstrated that broadly cross-reactive HVR1 T cells are elicited by HVR1.     

Enhancing the response to interferon-alpha.

BACKGROUND: Though initially recognized as antiviral agents, it was soon demonstrated that certain neoplasms were particularly sensitive to interferon-alpha (IFN-alpha). Indeed, the initial success of systemic IFN-alpha treatment in AIDS-associated Kaposi's sarcoma (AIDS-KS) occurred before identification of the human immunodeficiency virus (HIV) and in the absence of any coherent view of KS pathogenesis. With a more comprehensive understanding how KS develops and which circumstances provide an increased virulence of this neoplasm in HIV-infected persons, a more subtle rationale for IFN-alpha treatment arose regarding the disorder of the endogenous IFN-system in HIV-positive individuals. Until recently IFN-alpha was the only therapy available for patients with chronic hepatitis C (CHC). However, no more than 30% of these patients show a sustained virological response. Initial therapy with a combination therapy of IFN-alpha and ribavirin turned out to be more effective than treatment with IFN-alpha alone. To ameliorate response rates in antiviral IFN-therapy a profound understanding of viral dynamics, as well as immunological conditions associated with viral persistence, seems to be essential. Within a conference of the European Society of Clinical Virology (ESCV), which took place in Hamburg from August 30 to September 2, 1998, and was entitled 'Progress in Clinical Virology IV', a satellite symposium was organized to evaluate the clinical results of special antiviral treatment options with IFN-alpha, to analyze treatment failures with this cytokine and to ameliorate future strategies of IFN-alpha therapy. It focussed on HIV-related complications as coinfection with hepatitis C virus (HCV) and AIDS-KS, respectively. METHODS: A kinetic model of HCV infection based on principles established in studying HIV-1 infection was presented which is predictive for the outcome of IFN-alpha treatment. It involves different rates of velocity and compares the rates of acute clearance after different dosages of IFN-alpha application. Using the hypothesis to fit the changes in serum HCV RNA measured in a set of patients, it was found that 5 mIU daily dosing on average blocks 81% of HCV production/release, whereas 10 or 15 mIU blocks about 95% of HCV production/release. RESULTS: Only recently clinical data revealed a greater benefit of combination therapy with IFN-alpha and ribavirin compared to IFN-alpha alone in patients with chronic hepatitis C. In 345 CHC patients relapsing after pretreatment with IFN-alpha monotherapy, sustained response was achieved in a 10-fold higher degree with a combination of IFN and ribavirin compared to patients retreated with IFN alone. In 1775 treatment-naive patients with CHC, response rates to the combination therapy was significantly higher in all patient groups with more than 60% of sustained virological response in patients with genotype 2 and 3, while patients with genotype 1 (poorer prognosis) benefit from extended combination treatment duration from 24 to 48 weeks (17 versus 29% of sustained virological response), respectively. CONCLUSIONS: As viral dynamics on one side and host immune response on the other feature as two landmarks on which the manifestation of viral persistence and chronic viral infections is established, some similarities of HCV and HIV disease are striking. An unusual endogenous IFN-alpha system is associated with both infections and is a negative prognostic factor to response to treatment with IFN-alpha in CHC as well as AIDS-KS. The consequences for treatment options with IFN are a combination with ribavirin in CHC and a graduated systemic treatment schedule in AIDS-KS starting with IFN-treatment in early disease followed by chemotherapy in advanced stages of KS.     

Sodium beta-aescin may be an effective therapeutic agent for Bell's palsy

Although Bell's palsy is the most common acute facial paralysis, the cause of it is still unknown. This made the treatment for it remain very limited. Many methods are simply symptomatic treatment. Up to now we have known that Bell's palsy is related to viral infection and the pathomechanism of Bell's palsy involves inflammatory oedema and entrapment neuropathy in the narrow bony facial canal. So treatment plans for Bell's palsy mainly focus on antiviral therapy, relieving inflammatory oedema and accelerating facial nerve recovery. Sodium beta-aescin is derived from horse chestnut and its major constituent is aescigenin which has been approved by China national drug standard. The pharmacologic action of sodium beta-aescin is to relieve tissue oedema, recover vasopermeability and eliminate pressure caused by oedema. Nowadays sodium beta-aescin has been widely used clinically for encephaledema or tumefaction caused by trauma or operation. It also can be used for treating disease of digestive system and increasing intravenous tension and improving microcirculation. Although many papers had been published on the anti-edema effects of sodium beta-aescin, little was known about the effects in treating oedema complicated by Bell's palsy.     

Concomitant augmentation of type 1 CD4+ and CD8+ T-cell responses during successful interferon-alpha and ribavirin treatment for chronic hepatitis C virus infection

The combined interferon-alpha (IFN-alpha) and ribavirin (IFN-alpha/ribavirin) therapy for chronic hepatitis C virus (HCV) infection results in sustained viral eradication in 31%-64% of the patients. Previous studies have strongly suggested that HCV-specific T-cell responses maybe modulated during this therapy. The objective of this study was to further define the effect of IFN-alpha/ribavirin therapy on type 1 and type 2 HCV-specific CD4(+) and CD8(+) T-cell responses during IFN-alpha/ribavirin therapy. Toward this, serial CD8(+) T-cell responses to HCV-derived epitopes and CD4(+) T-cell responses to the HCV core antigen were analyzed in four patients before (baseline), during (at 24 weeks), and at the end (at 48 weeks) of IFN-alpha/ribavirin therapy. Therapy-induced viral clearance in three patients was associated with a significant augmentation of HCV-specific type 1 CD4(+) and CD8(+) T-cell responses. In contrast, in a patient who did not respond to therapy, a significant HCV-specific CD4(+) Th2 cell reactivity was observed accompanied by a lack of augmentation of the HCV-specific CD8(+) T-cell reactivity. These results indicate that enhancement of HCV-specific CD4(+) and CD8(+) T-cell responses is an important factor in determining the response to the IFN-alpha/ribavirin therapy and the outcome of the HCV infection.     

Soluble HLA class I antigens in chronic hepatitis C: a disease-associated manifestation or molecules modulating immunoresponsiveness?

The occurrence of high levels of soluble human leukocyte class I antigens (sHLA-I) represents an usual finding during the course of different clinical conditions, such as viral infections and autoimmune disorders. On the other hand, the well known property of sHLA-I to modulate T cell responsiveness could be taken as an advantage to improve long-term allograft acceptance. Recent data have pointed out that subjects with chronic hepatitis C virus (HCV) infection exhibit high amounts of sHLA-I, a pattern which has also been used for monitoring host responsiveness to interferon alpha (IFN-alpha) therapy. However, the lack of correlation between lymphocyte infiltration at liver site and disease biological activity suggests a potential role for sHLA-I in T cell dysfunction during chronic hepatitis C. sHLA-I antigens may, in fact, either interact with T cell receptor delivering an inhibitory signal or trigger cytotoxic T lymphocyte apoptosis by inducing CD95 ligand expression. Both events seem to favour HCV replication and liver tissue damage progression. Alltogether, these findings indicate that, besides viral variant generation and HCV core-mediated immunosuppression, sHLA-I may contribute to the imbalance of immunoresponsiveness during chronic HCV infection.     

Soluble CD26/30 levels before and after treatment with interferon-alpha and ribavirin combination therapy in a pediatric hepatitis C patient.

Chronic hepatitis C virus (HCV) infection frequently leads to end-stage liver diseases and extrahepatic complications. Combination therapy with interferon-alpha (IFN-alpha) and ribavirin is now recommended as the first-line therapy for patients with chronic hepatitis C in adults. However, the benefit of such combination therapy in children with hepatitis C is still under investigation. We report here on a 6-year-old boy admitted with chronic active hepatitis C infection and treated with interferon-alpha and ribavirin. After treatment for 12 months, his serum showed negative HCV RNA, and normal alanine aminotransferase, and there was a sustained response. The patient's serum soluble CD30 (sCD30) level was higher than that of controls (>100 U/mL vs 46 +/- 11 U/mL) before combination therapy but there was no difference in soluble CD26 (sCD26) [103 ng/mL vs 119 +/- 28 ng/mL]. The sCD30 decreased and sCD26 increased at 6 months (45 U/mL and 188.3 ng/mL, respectively) using combined therapy as well as at 4 months after discontinuing it (33 U/mL and 167.8 ng/mL, respectively) in our patient. The results indicate that combined treatment with IFN-alpha and ribavirin may be used as the first-line treatment for children with chronic hepatitis C. The changes of sCD30 and sCD26 may be helpful in estimating of HCV infection activity.     

Bell's palsy may have relations to bacterial infection

Bell's palsy is the most common acute facial paralysis with its causes still unclear. At present, the most widely accepted causes are viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. Unclear causes lead to unidentified treatments. Most therapeutic methods are simply symptomatic treatment. Fortunately, the pathomechanism of Bell's palsy is relative clear, involving herpes simplex virus (HSV) reactivation within the geniculate ganglion, followed by inflammation and entrapment of the nerve in the bony foramen. This makes symptomatic treatment possible. But the therapeutic effects are not quite satisfactory. Therefore, novel etiological and therapeutic concepts are urgently needed. According to our clinical observation and some facts that do not favor the viral infections theory, we can conclude that all Bell's palsy is not related to viral infections, some even may have relations to bacterial infection. As far as blood routine examination is concerned, though lymphocyte increasing can be seen in most patients with Bell's palsy, there are cases with normal lymphocyte but increased neutrophil. Also, antibiotic treatment in these patients could accelerate recovery to some extent. These results indicate that Bell's palsy in these patients may be caused by bacterial infection.     

Minimal change disease in a patient receiving IFN-alpha therapy for chronic hepatitis C virus infection.

Chronic hepatitis C virus (HCV) infection is associated with several extrahepatic syndromes. The principal types of renal disorders associated with chronic HCV infection are cryoglobulinemia or noncryoglobulinemic membranoproliferative glomerulonephritis (MPGN). Interferon-alpha (IFN-alpha) may precipitate or exacerbate the occurrence of MPGN. Our patient was a 32-year-old man who tested positive for HCV in July 1997. The patient was treated with IFN-alpha in another medical center for 6 months because his liver biopsy showed chronic active hepatitis. In December 1998, he applied to our clinic for a follow-up examination. The level of aspartate aminotransferase (AST) was 44 U/L, and that of alanine aminotransferase (ALT) was 69 U/L. HCV RNA was positive in serum, and chronic HCV infection was detected by liver biopsy. IFN-alpha therapy (5 million U/day) was administered for 6 months longer. In May 1999, the patient came to our polyclinic with edema of the feet and legs. We detected proteinuria, serum cholesterol of 269 mg/dl, AST of 50 U/L, ALT of 41 U/L, serum total protein of 3.4 g/dl, serum albumin of 1.2 g/dl, positive cryoglobulin, and urine protein of 9.84 g/day. Cryoglobulinemic MPGN was suspected and kidney biopsy was performed, resulting in a diagnosis of minimal change disease (MCD).     

Hepatitis C virus genetic variability in patients undergoing antiviral therapy

Hepatitis C virus (HCV) has been the subject of intense research and clinical investigations due to its worldwide prevalence and major role in chronic liver disease. Like most RNA viruses, HCV circulates in vivo as a complex population of different but closely related viral variants, commonly referred to as a quasispecies. Recent studies suggest that ribavirin might exert an antiviral effect against HCV through both mutagenic effect and an impairment of RNA replication. The introduction of alpha interferon (IFN-alpha) plus ribavirin combination therapy was an important breakthrough in the treatment of chronic HCV infection. However, the rate of sustained virological response is still unsatisfactory, particularly in patients infected with HCV genotype 1. Viral persistence, a hallmark of HCV, may result from a dynamic control of the host response by the virus. In children with chronic HCV infection, the viral population is initially highly homogeneous, but diversifies during prolonged infection which seems to be a common event during chronic hepatitis C in childhood. Coinfection of human immunodeficiency virus 1 (HIV-1) patients by HCV can complicate the treatment of these patients with highly active antiretroviral therapy (HAART). HIV coinfection is associated with a decrease of HCV quasispecies variability, which appears to be reversed by effective HAART.     

Viral determinants of resistance to treatment in patients with hepatitis C

Chronic hepatitis C virus (HCV) infection affects more than 170 million persons worldwide and is responsible for the development of liver cirrhosis in many cases. Standard treatment with pegylated alpha interferon (IFN-alpha) in combination with the nucleoside analogue ribavirin leads to a sustained virologic response in approximately half of the patients. IFN-alpha is classified as an indirect treatment, as it interacts with the host's immune response. The mechanism of action of ribavirin is still unknown. The benefit of triple therapy by adding other antiviral agents, e.g., amantadine, is controversial. Currently, new direct antiviral drugs (HCV protease/polymerase inhibitors) are being evaluated in phase 1/phase 2 trials. Phenotypic resistance to antiviral therapy has been attributed to amino acid variations within distinct regions of the HCV polyprotein. While sensitivity to IFN-alpha-based antiviral therapy in vivo is clearly correlated with the number of mutations within the HCV NS5A protein, the underlying functional mechanisms for this association are unknown. In turn, in vitro, several mechanisms to circumvent the host immune defense or to block treatment-induced antiviral activities have been described for different HCV proteins. By the introduction of direct antiviral drugs, hepatitis C therapy now is entering a new era in which the development of resistance may become the most important parameter for treatment success or failure.     

Pernicious anemia during IFN-alpha treatment for chronic hepatitis C.

Some latent diseases, such as immune disorders, can appear during interferon-alpha (IFN-alpha) therapy. These disorders are difficult to predict because of their low prevalence in the general population. We describe a case of pernicious anemia (PA) in a patient affected by chronic hepatitis C and macrocytosis during IFN-alpha therapy. Hemoglobin (Hb) concentration reached 7.3 g/dl. Anti-intrinsic factor (IF) antibodies were present, but not antiparietal cell antibodies (APCA). Suspension of IFN-alpha and administration of vitamin B(12) resulted in normal Hb concentrations. This case is the first instance of early PA (at the second month of IFN therapy) in a patient affected by chronic hepatitis C. The only other case of PA in a patient affected by hepatitis C virus (HCV) infection occurred during the second year of maintenance IFN therapy. We recommend that particular attention be paid to such clinical and laboratory conditions as macrocytosis in administering IFN-alpha therapy for chronic hepatitis C.     

Interferon-alpha induces interleukin-18 binding protein in chronic hepatitis C patients

Interleukin-18 (IL-18), derived from macrophages and Kupffer cells, is the central pro-inflammatory cytokine leading to experimental liver failure. IL-18 binding protein (IL-18BP) is a circulating protein that binds IL-18 and neutralizes its activity. Since IL-18 production is increased in chronic HCV infection, we asked whether IFN-alpha might act on the IL-18/IL-18BP system in HCV patients. IL-18BP, total and free IL-18 plasma levels were determined in 13 HCV patients receiving 1 x 107 IU IFN-alpha subcutaneously daily for 28 days. The in vitro effects of IFN-alpha on macrophage IL-18BP and IL-18 were studied by enzyme-linked immunosorbent assays and Northern analysis. IFN-alpha administration increased IL-18BP plasma levels 3.24 fold 24 h after institution of therapy, resulting in a 67.4% reduction of free IL-18. Total IL-18 levels decreased from day +24 on. In vitro, IFN-alpha diminished IL-18 release from macrophages of healthy volunteers and chronic HCV patients. On top of its inhibitory effects on IL-1 and TNF-alpha release, IFN-alpha also exerts its anti-inflammatory action in vivo by induction of IL-18BP. These anti-inflammatory properties might account - together with its antiviral action - for its clinical efficacy in chronic hepatitis C.     

Twenty-four hour kinetics of hepatitis C virus and antiviral effect of alpha-interferon

Numerous studies reported that patients infected by the genotype 1 of hepatitis C virus (HCV) and/or with a high baseline viral load responded poorly to antiviral therapy. Study of viral kinetics has provided clues to the understanding of non-response to alpha-interferon (IFN-alpha)-based therapy. The objective of this study was to clarify the influence of viral factors such as the genotype and baseline viral load on HCV resistance to treatment through the study of their impact on the first phase of viral decline. HCV RNA levels were determined frequently following the administration of 3 million units of IFN-alpha in 22 chronic HCV carriers. The evolution of HCV RNA level over 24 hr was different in genotype 1-infected patients, compared to that in patients infected by other genotypes. The viral load decline at 24 hr was lower in patients with genotype 1. Patients with a high baseline viral load exhibited a viral dynamics different from patients with a lower level of viremia; the extent of the first phase was also lower in these patients. Non-responder patients had a slower viral decay on day 1 of therapy than patients who cleared the virus under treatment. In conclusion, 24 hr HCV dynamics is regulated by genotype and baseline viral load. Genotype 1 strains and those that produce high viral loads are the most resistant to the antiviral action of IFN-alpha. Resistant HCV strains could be distinguished from sensitive viruses as early as a few hours after the beginning of the treatment.     

Primary Epstein-Barr-virus infections in acute neurologic diseases.

Infectious mononucleosis has been associated with Guillain--Barré syndrome, Bell's palsy, meningoencephalitis and transverse myelitis. Since it is not known that many children with infectious mononucleosis do not develop heterophil antibodies, we looked for evidence of current or recent Epstein-Barr virus infection in young patients with these neurologic diseases by using serodiagnostic procedures for detection and titration of antibodies to various antigens related to Epstein-Barr virus. Seven of 24 cases with Guillain-Barre syndrome and three of 16 with facial palsy were definitely associated with primary infection with Epstein-Barr virus as were two cases each of the other two neurologic diseases. Only one of these patients had obvious clinical infectious mononucleosis, and only a few demonstrated heterophil agglutinins. It is evident that the virus must be considered in the diagnosis of various acute neurologic diseases affecting children and young adults, even in the absence of heterophil-antibody response or other signs of infectious mononucleosis.     

Changes in TNF-alpha mRNA levels in the peripheral blood of patients with chronic hepatitis C virus (HCV) infection during alpha-interferon and ribavirin therapy

HCV virus infections have become a serious epidemiological problem throughout the world. Hepatitis C therapy includes the administration of IFN-alpha and ribavirin, but results in the complete eradication of HCV viremia in only 30% of patients. TNF-alpha is one of the factors involved in hepatitis C pathogenesis and the results of therapy. In this study, we present the results of applying real-time RT-PCR for assessing the TNF-alpha mRNA level in the peripheral blood of patients treated with IFN-alpha and ribavirin. We found the TNF-alpha mRNA level to be higher in HCV-infected patients compared with healthy controls when analyzed after 4 weeks (p = 0.001) and 3 months (p = 0.003) of IFN-alpha/RIBA therapy. The pretreatment level and the level after six months of therapy were not significantly different from the level of healthy controls. There were no significant differences in TNF-alpha mRNA levels between patients who responded to anti-HCV therapy, resulting in a decrease in HCV viremia below detection limit over 6 months and patients whose HCV RNA was not eliminated (p = 0.881). These results indicate that there is a transient increase of TNF-alpha gene expression during anti-HCV therapy. This fact may be connected with the host organism's response to IFN-alpha/RIBA therapy.     

Intrahepatic MxA and PKR protein expression in chronic hepatitis C virus infection

The therapeutic effect of interferon-alpha and ribavirin in the treatment of chronic hepatitis C viral infection is limited. To identify patient characteristics that may predict responsiveness to treatment, the intrahepatic protein expression of two directly induced IFN-alpha effector proteins, MxA and PKR, were studied. Forty liver biopsy samples from patients with a variety of chronic liver diseases were stained for MxA and PKR protein using immunohistochemical techniques. In a HCV patient cohort, 30 liver biopsies were stained for MxA and PKR protein prior to treatment with IFN-alpha and ribavirin. PKR protein expression was not upregulated in viral liver disease. In contrast, MxA protein expression was significantly upregulated in viral liver disease (P = 0.005). In chronic HCV liver disease, moderate to strong cytoplasmic expression of MxA protein was observed in hepatocytes and monocytes, indicating endogenous hepatocellular IFN-alpha pathway activation. In the HCV patient cohort treated with combination therapy, strong pre-treatment MxA hepatocyte expression was predictive of a non-response to treatment (odds ratio 9.33; P = 0.01; 95% confidence interval 1.63-53.2). This effect was independent of HCV genotype and viral load. It is concluded that pretreatment hepatocellular MxA expression may become a useful predictor of response to combination treatment with IFN-alpha and ribavirin.