Immunological studies before and during interferon therapy in chronic HBV infection: identification of factors predicting response

Hepatitis B virus infection: An insight into infection outcomes and recent treatment options

Hepatitis B virus (HBV) currently infects an estimated population of 2 billion individuals in the world, including 400 million people with chronic HBV infection. HBV virology, replication and the host's immune response to HBV infection contribute to different infection outcomes. Acute hepatitis HBV infection is self-limiting but it leaves a residual infection that can become active in an individual during immunosuppression. In chronic HBV infection, the virus persistently replicates in hepatocytes leading to immune mediated hepatocellular damage. Despite the inability to remove the virus in more than 70 % of patients, current treatments for chronic HBV infection, interferon alpha and antiviral nucleotide/nucleoside analogues, aim to reduce viral replication to prevent or at least delay the progression to cirrhosis and hepatocellular carcinoma. In both self resolved acute and persistent HBV infection, the long term existence of chromatinised covalently closed circular DNA (cccDNA) in the nuclei of infected hepatocytes cannot be targeted by current treatments to eliminate these templates to eradicate the viral persistence. Identifying the mechanisms involve in the removal of infected hepatocytes will be useful as treatment options. In this context, DNA based novel therapeutic and immunization strategies might help to remove stable cccDNA and thus viral persistence.

The influences of antiviral therapy on T-cell function in adult patients with chronic hepatitis B

ABSTRACT 

T cells play an important role in the clearance of acute infection and control of hepatitis B virus (HBV) infection during the chronic phase. Chronic HBV is characterized by a weak and limited T-cell response. Several hypotheses, such as presence of Tregs or occurrence of T-cell exhaustion have been proposed to explain these observations. The two registered classes of anti-HBV drugs: pegylated-IFN-α (PEG-IFN-α) and nucleos(t)ide analogs (NUCs) have, next to their antiviral effect, also an immunomodulatory effect. Although NUCs have no direct immunomodulatory effects, they may indirectly positively affect the T-cell response through their viral suppressive action. In this review, effects of both PEG-IFN-α and NUC therapy will be discussed with regard to the cellular immune response against HBV.

Genetic structural differences between responders and non-responders to interferon therapy for chronic hepatitis-B patients

Interferon-alpha therapy has become a main stay of treatment for hepatitis-B patients. The sustained remission rates are around 30%, and the factors determining response are poorly defined. Our study aimed to search for the genetic differences between responder and non-responder patients. We have found 13 short tandem repeat markers (STR) that display different allele and/or genotype frequency between the two patient groups. Eleven out of 13 STR markers were selected to perform principal component analysis and hierarchical clustering. The study subjects could be further divided into six groups based on their genetic similarity, which correlated with the drug response rate. In conclusion, this pilot study has developed a new approach to identify genetic markers that allows us to predict the drug response in hepatitis B patients. Our study utilizing STR markers may provide an alternative approach to the utilized SNP markers in pharmacogenetic study.

Poor response to 18-month lamivudine monotherapy in chronic hepatitis B patients with IgM anti-HBc and acute exacerbation

BACKGROUND

Appearance of immunoglobulin class M antibody against hepatitis B core antigen is a predictor of beneficial response to interferon-alpha therapy in chronic hepatitis B patients, but its relationship with the efficacy of lamivudine therapy remains unclear.

AIM

To investigate the outcome of lamivudine therapy in chronic hepatitis B patients with immunoglobulin class M antibody against hepatitis B core antigen and acute exacerbation.

METHODS

Chronic hepatitis B patients with acute exacerbation receiving a national-wide therapeutic trial of 18-month lamivudine monotherapy were enrolled for the analysis. Four consecutive seronegative patients were recruited as individual matching controls of one positive subject. Immunoglobulin class M antibody against hepatitis B core antigen in serum was assayed monthly by an automated microparticle enzyme immunoassay.

RESULTS

Fifteen (8.9%) of 167 chronic hepatitis B patients with acute exacerbation were seropositive for IgM anti-HBc. Thus 60 seronegative patients were consecutively recruited as control group. At the end of therapy, two (13.3%) of the 15 seropositive patients achieved a sustained response, significantly lower than 26 (43.3%) of the control group.

CONCLUSIONS

Appearance of immunoglobulin class M antibody against hepatitis B core antigen in chronic hepatitis B patients with acute exacerbation is a predictor of poor response to lamivudine monotherapy. This is clinically relevant to the decision-making in treating chronic hepatitis B patients with acute exacerbation.

Microarray profiling of antiviral antibodies for the development of diagnostics, vaccines, and therapeutics

Multiplex analysis of antiviral antibody (Ab) responses provides a potentially powerful strategy for viral diagnosis, prognostication, and development of vaccines and prophylactic Abs. In the coming years, advancements in proteomic technologies will provide even more robust methods to characterize antiviral Ab responses. Biomedical researchers will be faced with the exciting challenge of identifying antiviral Ab specificities that correlate with improved outcomes and efficacious interventions, and translating the findings into more effective diagnostics, prophylactics, and therapeutics.

Decreased ratio of CD4/CD8 lymphocytes might be predictive for successful interferon alpha and lamivudine combined therapy in childhood chronic hepatitis B infection: A preliminary study

BACKGROUND

In the development of chronic hepatitis with hepatitis B virus infection and in response to therapy, the immune status of the infected host plays a critical role. In this study, immunological variables were assessed in patients before interferon alpha and lamivudine therapy to determine if any pretreatment immunological parameter could be an indicator of response to therapy in childhood chronic hepatitis B infection.

METHODS

Forty-four patients with chronic hepatitis B virus infection, aged 9.0 +/- 3.9 years, were enrolled in the study. The pretreatment clinical features, biochemical test results, histological activity indexes and immunological parameters were evaluated. All patients received interferon alpha for 6 months and lamivudine for 52 weeks. Four patients who could not be followed up were excluded from the study. The other 40 patients have been followed for a mean period of 27.5 +/- 9.7 months after therapy discontinuation.

RESULTS

Seventeen patients showed loss of hepatitis B early antigen (HBeAg) with appearance of anti-HBe (42.5%) and six of those who responded also showed loss of hepatitis B surface antigen (HBsAg) with the presence of anti-HBs (15%). Except elevated aspartate aminotransferase levels, there was no significantly correlation between response and sex, age, pretreatment duration of disease and histological activity indexes. Pretreatment immunoglobulins (Ig), IgG subclasses, complement C3, C4 and secretory IgA levels were also not found to be significantly related to response. The evaluation of lymphocyte subsets showed that therapy responders had significantly reduced pretreatment ratios of CD4/CD8+ lymphocytes due to prominent increased percentages of CD8+ cells. The other cellular immunity parameters and some cell surface adhesion molecules were similar in both groups.

CONCLUSION

This study emphasizes the importance of increased pretreatment CD8+ lymphocyte percentages leading to a significant decrease in CD4/CD8 ratio in chronic hepatitis B virus infection of childhood as an immunological factor predicting response to treatment.

HLA class II alleles in Chinese patients with hepatocellular carcinoma

BACKGROUND/AIMS

Recent reports of an association between human leucocyte antigens (HLA) and persistence of hepatitis B virus infection, and the familial clustering of hepatocellular carcinoma raise the question of genetic susceptibility. Previous studies have been limited to serological phenotyping of HLA B and DR antigens. The aim of this study was to use molecular genotyping to investigate HLA class II as a risk factor for the development of hepatocellular carcinoma in Hong Kong Chinese.

METHODS

We determined HLA DRB1, DQA1, DQB1 and DPB1 alleles in 123 hepatitis B surface antigen positive patients (84 with hepatocellular carcinoma and 39 without) and 124 matched controls.

RESULTS

The alleles DRB1*1501 (36% of HCC patients versus 19% of controls, odds ratio=2.44), DQA1*0102 (42% versus 26%, odds ratio=2.07), and DPB1*0501 (80% versus 63%, odds ratio=2.35) were significantly more common in patients with hepatocellular carcinoma, and DQA1*03 (36% versus 56%, odds ratio=0.53), DQB1*0302 (4.% versus 13%, odds ratio=0.25) and DPB1*0201 (14% versus 29%, odds ratio=0.4) were found at significantly lower frequencies.

CONCLUSIONS

Although none of these associations was significant after correction for multiple testing, this report suggests that further investigations are warranted.

Quantitative monitoring of serum hepatitis B virus DNA and blood lymphocyte subsets during combined prednisolone and interferon-alpha therapy in patients with chronic hepatitis B

Several investigators have reported a significantly reduced CD4/CD8 ratio, as defined by monoclonal antibodies, in the peripheral blood of Caucasian patients with chronic active hepatitis B (CAHB). In Asian patients with chronic hepatitis B, quantitative analyses of subpopulations of peripheral blood lymphocytes have not been able to confirm these findings. In this work, we analysed the frequency of peripheral blood lymphocyte subsets in 10 Chinese patients with histologically proven CAHB and seven healthy Chinese individuals. Four of the 10 CAHB patients received combined prednisolone/interferon-alpha2b (IFN-alpha2b) therapy. Peripheral blood samples were consecutively collected for analysis of lymphocyte subpopulations using an indirect immunofluorescence (IF) method, and hepatitis B virus (HBV) DNA was quantified by a chemiluminescent, molecular-hybridization assay. Peripheral blood mononuclear cells from seven Chinese control individuals comprised 63 +/- 3% CD3+ cells, of which 41 +/- 4% were of CD4+ and 23 +/- 2% of CD8+ subsets. The mean CD4/CD8 ratio in the healthy controls was 1.9 (95% confidence interval = 1.1-2.7). The CD4/CD8 ratios were significantly reduced (P < 0.01) in the 10 patients with chronic hepatitis B, compared with those of the controls, owing to a significant increase in the number of CD8+ cells (P < 0.005). During the treatment with prednisolone, a significant increase in the CD4/CD8 ratio was observed in all treated patients. This increase was mainly caused by a decrease in the number of CD8+ cells and was accompanied by an increase in serum HBV DNA levels, which peaked during the latter part of the prednisolone cycle. During the treatment with IFN-alpha2b, a second increase in the CD4/CD8 ratio was observed, which was caused by an increase in CD4+ cells. A marked decrease in viral load was observed, during treatment with IFN-alpha2b, in patients with HBV DNA levels below 10 000 pg ml-1. Our data indicate that the CD4/CD8 ratios in Chinese CAHB patients do not differ from those of Caucasian patients with CAHB, when analysed using similar methods for the enumeration of lymphocyte subsets. Profound effects on cellular distribution and viral replication were noted during the combined prednisolone/IFN-alpha2b therapy. Additional studies of the modulatory effect of the combined therapy on the distribution of lymphocyte subsets and cytokine profiles in relation to the therapeutic outcome of HBV infection are warranted.

IgM antibody response to the hepatitis C virus core protein in intravenous drug users

To verify whether a solid-phase enzyme immunoassay for serum IgM antibodies to the hepatitis C virus (HCV) core protein (IgM anti-HCVcore) might be proposed as a surrogate test for serum HCV RNA, we studied 86 anti-HCV antibody-positive intravenous drug users. Serum HCV RNA was demonstrated by RT-PCR with primers derived from the 5' non-coding and the core region. IgM anti-HCVcore antibodies were found in 62/86 (72%) subjects; circulating HCV RNA was detected by the 5' noncoding assay in 53/86 samples (62%) and by the core region assay in 35/86 samples (41%). IgM anti-HCVcore reactivity was associated with core HCV RNA seropositivity (p < 0.05) but not with 5' noncoding HCV RNA seropositivity (p = NS). Patients infected by HCV type 1a were more-often positive for IgM anti-HCVcore (p < 0.05) and for core HCV RNA (p = 0.005) than patients infected by other HCV genotypes. IgM anti-HCVcore reactivity was significantly more common in subjects positive for core HCV RNA (p < 0.005) and in subjects aged > 30 years (p < 0.05). In conclusion, the IgM anti-HCVcore assay frequently tests positive in intravenous drug users, particularly when infected by HCV 1a, but is not a surrogate of testing for serum HCV RNA.

Possible association between HLA antigens and the response to interferon in Japanese patients with chronic hepatitis C

Correlation between the major histocompatibility complex class I antigens (HLA-A, -B and -C) and the elimination from serum of hepatitis C virus in patients with chronic hepatitis C has not been understood. We analyzed HLA phenotypes and their relationship to the efficacy of interferon treatment. Of the 172 patients who were treated with 9 million units of interferon-alpha 2a three times a week for 6 months, 54 patients were responders and 118 patients were non-responders. No significant difference was observed between the 172 patients and 199 healthy subjects with regard to the frequencies of HLA-A, -B and -C antigen phenotypes. However, HLA-B55, B62, CW3 and CW4 frequencies were significantly higher in responders than in non-responders to the interferon treatment. CW4 was found to link with B62, but other phenotypes were independent each other. Patients with HLA B55, B62 and CW3 had a significantly lower viral load, and showed a better response to interferon. These results suggest that HLA system does not have an influence on the evolution towards chronicity of the disease due to hepatitis C virus, but HLA B55, B62 or CW4, and CW3 may be a virus quantity-regulating factors which then affect to response to the interferon treatment, indicating that these HLA antigens in conjunction with a viral peptide is a key target antigen for cytotoxic T lymphocytes in patients with chronic hepatitis C.

Immunogenetics in liver disease

Recent advances in molecular biology, in particular X-ray crystallography of the purified antigens A2 and DR1 and development of PCR-based HLA genotyping techniques, has revolutionized our understanding of immunogenetics and cellular immunology. The application of molecular immunogenetics has refined our understanding of HLA-encoded susceptibility and resistance to both autoimmune and chronic viral liver disease. Recent studies of autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC) have identified substitutions of specific amino acid residues in the HLA DR beta-polypeptide (AIH and PSC) and DP beta-polypeptide (PBC) which may determine susceptibility to and resistance from disease. Although these models of HLA-encoded susceptibility in PSC and PBC are currently controversial, the model for AIH, based on lysine residue at DR beta 71 has recently been confirmed in an independent series. Data on chronic viral liver disease are less abundant, but a number of interesting observations are beginning to emerge. In the Gambia, resistance to chronic hepatitis B infection has been associated with the HLA DRB1*1302 allele, and in studies of patients with chronic hepatitis C virus infection DQA1*03 and DQB1*05 have been identified as a possible protective factors. Clarifying these HLA associations is not simply an academic pursuit; in addition to providing useful clues to the pathogenesis of these diseases, HLA associations may be important indicators of prognosis. In AIH, patients with the DRB1*0301-DRB3*0101 haplotype appear to have more severe disease than those with DRB1*0401, while in PSC, DRB3*0101 is associated with early onset of disease and DRB1*0401 may be a marker of more rapid disease progression. To date, our knowledge of immunogenetic susceptibility in liver disease is incomplete and further work is needed.

Immunological effects following administration of interferon-alpha in patients with chronic hepatitis C virus (cHCV) infection

The immunological effects of interferon (IFN)-alpha administration were evaluated in 15 patients with cHCV infection. Individuals were treated with 6 MU of lymphoblastoid IFN-alpha three times a week for 6 months and with 3 MU three times a week for an additional 6 months. Patients were divided into responders (12 subjects) and nonresponders (3 subjects), respectively, according to alanine aminotransferase serum levels at the end of treatment. Before therapy (T0), absolute numbers of CD3+, CD4+, CD8+, CD14+ and CD16+ cells were significantly reduced in both groups when compared to normal values. At the same time, all patients displayed a profound decrease of phagocytosis and killing exerted by both polymorphonuclear cells (PMN) and monocytes (MO). However, MO Killing resulted to be normal in the responder group. With special reference to T cell function, T cell mediated antibacterial activity, using Salmonella typhi as a target, was also significantly reduced. After therapy (T12), in responder patients a significant increase of CD3+, CD4+, CD14+ and CD16+ cell absolute numbers was observed, while phagocytic and T cell functions were still depressed. Among the nonresponders, in two of three patients IFN-alpha administration gave rise to an increase (above normality) of CD3+, CD4+, CD8+, CD14+, CD16+ and CD20+ cell absolute numbers, while in one patient the same markers dramatically dropped below normal range. In two patients, antibacterial activity was significantly augmented by IFN-alpha treatment, whereas in one patient no modification was observed. Finally, in the same patients IFN-alpha did not correct PMN and MO pretreatment deficits.

Quantitative assessment of IgM antibodies towards an immunodominant B-cell epitope within the preS2 domain of HBV in the natural course and during combined prednisone/interferon alpha 2b treatment of chronic hepatitis B virus infection

A direct binding enzyme-linked immunosorbent assay (ELISA) was established for quantitative determination of serum IgM antibodies towards a synthetic peptide corresponding to a selected segment (14-21) of the preS2-gene product containing an immunodominant linear B-cell epitope. The prevalence of IgM anti-preS2 (14-21) antibody titers > 1,000 for hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B virus (HBV) infection was 38% (22/58) and 10% (2/21) for HBeAg-negative subjects (P < 0.005). IgM anti-preS2 (14-21) reactivity was detected during the clinical course of chronic HBV infection and IgM anti-peptide antibody titers declined and disappeared before spontaneous HBe/anti-HBe seroconversion. Recombinant interferon (IFN)-alpha 2b with an antecedent short course of corticosteroids was administered to eight Chinese patients with chronic HBV infection. The IgM anti-preS2 (14-21) reactivity was monitored consecutively during treatment and patients were followed for more than 1 year. A close association between the presence of pretreatment IgM anti-preS2 (14-21) in serum and the capacity to respond favorably to the combined prednisone/IFN-alpha 2b therapy was detected. The IgM anti-preS2 (14-21) titers decreased during treatment with subsequent loss of detectable antibodies 8-16 weeks after the initiation of therapy. This decrease was concomitant with an alanine aminotransferase (ALT) augmentation preceding the disappearance of HBV-DNA and anti-HBe seroconversion. Long-term remission was not observed in treated patients who lacked detectable levels of pretreatment IgM anti-preS2 (14-21) in the circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Association between an MHC class II allele and clearance of hepatitis B virus in the Gambia

BACKGROUND

The course of hepatitis B virus (HBV) infection does not appear to be determined by variations in viral virulence and may be influenced by the host immune response. We studied the distribution of human leukocyte antigens in children and adult men in the Gambia who spontaneously recovered from HBV infection as compared with the distribution of these antigens in subjects with persistent infection.

METHODS

In a two-stage, case-control study, we analyzed the frequency of MHC class I antigens and class II haplotypes in people with either transient or persistent HBV infection. MHC class I typing was performed by microlymphocytotoxicity assays. MHC class II typing was performed with analysis of restriction-fragment-length polymorphisms (RFLPs), supplemented by other techniques.

RESULTS

In the first stage (the study of children up to the age of 10 years), the RFLP pattern 25-1, which includes the class II allele HLA-DRB1*1302, was found in 58 of 218 subjects with transient HBV infection (26.6 percent) and 30 of 185 subjects with persistent infection (16.2 percent) (relative risk of carrying the 25-1 pattern in the persistently infected group as compared with the transiently infected group, 0.53; 95 percent confidence interval, 0.32 to 0.90; P = 0.012). In the second stage (the study of adults), HLA-DRB1*1302 was found in 50 of 195 subjects with transient HBV infection (25.6 percent) and in 3 of 40 subjects with persistent infection (7.5 percent) (relative risk, 0.24; 95 percent confidence interval, 0.04 to 0.80; P = 0.012). The RFLP pattern 13-2, which includes the class II allele DRB1*1301, was less frequent in children with persistent infection than in those with transient infection, an association that was neither confirmed nor excluded by the data on adults. Possible associations with HLA class I antigens found in children were not supported by the data on adults.

CONCLUSIONS

The MHC class II allele DRB1*1302 was associated with protection against persistent HBV infection among both children and adults in the Gambia.

Quantitative assessment of serum IgM anti-HBc in the natural course and during interferon treatment of chronic hepatitis B virus infection

Serum IgM anti-HBc was determined in 135 chronic HBsAg carriers with various categories of histological activity on liver biopsy and hepatitis B serological profile. Thirty-three patients were treated with interferon-alpha to investigate the correlation between serum IgM anti-HBc with histological activity and viral replication, to evaluate the usefulness of pretreatment IgM anti-HBc as a predictor of a successful response to interferon-alpha and to examine the IgM anti-HBc response during this treatment. All 53 patients with chronic active hepatitis with either wild-type (n = 42) or precore mutant variant HBV infection (n = 11) had an IgM anti-HBc index greater than 0.300 compared with 7.4% (2 of 27) of the chronic HBsAg/HBeAg-positive carriers with chronic persistent hepatitis, 10% (3 of 30) of the anti-HBe-positive asymptomatic carriers and none of the 25 patients with hepatitis D virus-positive chronic active hepatitis (p < 0.0001). Pretreatment IgM anti-HBc index was greater than 0.300 in 82.4% (14 of 17) of HBeAg/HBV DNA-positive patients who seroconverted after interferon-alpha treatment compared with 25% (4 of 16) of the patients who did not seroconvert (p = 0.0013), whereas an elevated pretreatment AST was present in only 52.9% (9 of 17) of responders and in 37.5% (6 of 16) of nonresponders (p = 0.42). Serial testing of IgM anti-HBc in these 33 patients during interferon-alpha treatment showed a significant rise in IgM anti-HBc in all responders, which followed the AST flare-up but preceded the time of the HBeAg to anti-HBe seroconversion.(ABSTRACT TRUNCATED AT 250 WORDS)

Alpha-interferon enhances gamma-interferon production of peripheral blood mononuclear cells pre-activated with phytohemagglutinin

The question of whether the state of T cell activation is responsible for gamma-interferon production in response to alpha-interferon was determined. When peripheral blood mononuclear cells were pre-incubated with phytohemagglutinin for 3 days, their gamma-interferon production was found to be augmented by alpha-interferon, accompanied by an increased proportion of DR-positive T cells. This did not occur with fresh cells. The effect was dose-dependent and inhibited by anti-alpha-interferon antibody. Therefore, alpha-interferon was considered to enhance the production of gamma-interferon of pre-activated peripheral blood mononuclear cells but not of resting ones. In conclusion, alpha-interferon augmented the production of gamma-interferon of peripheral blood mononuclear cells only when they had already been activated, suggesting a role of alpha-interferon as a modulator of the cellular immune response.

Haemolytic anaemia to the alpha-interferon treatment: a proposed mechanism

Auto-immune haemolytic anaemia (AIHA) has been found in a case of alpha-interferon treatment. Serum antibody and eluate were positive in the absence of the drug. Although the patient recovered after the treatment was stopped, DAGT remained positive for at least 8 months. The mechanism proposed to explain why this drug induced AIHA is similar to that proposed for alpha-methyl-dopa. Drugs could alter the red cell membrane and impair the immune system. Such changes have been observed with alpha-interferon and were related with increased autoimmunity.

Effects of interferon-alpha treatment on hepatitis B virus antigen-specific immunologic responses in patients with chronic hepatitis B

Studies were undertaken to evaluate the relationship between the immune responses and the effectiveness of interferon-alpha treatment in 21 patients with HBeAg-positive chronic active hepatitis. Peripheral blood mononuclear cells (PBMC), obtained on four occasions during an 8-week course of IFN-alpha therapy, were cultured with recombinant HBcAg, purified HBeAg or pokeweed mitogen (PWM). During follow-up for 6 months after therapy, clearance of serum HBeAg was observed in eight patients designated as responders. Immunological responses of PBMC obtained before treatment did not differ between responders and non-responders. In responders, IFN-gamma and anti-HBc production was depressed during therapy, but recovered to above the pretreatment level at the end of and/or after cessation of therapy, while lymphocyte proliferation was enhanced during therapy with a subsequent decline to baseline value. In non-responders, such changes were modest throughout the study, and anti-HBc response remained decreased even after cessation of therapy. These results indicate that PBMC of responders have immunologically different responses to IFN-alpha therapy when compared with non-responders.

Repeated courses of alpha-interferon for treatment of chronic hepatitis type B

In chronic hepatitis B transition from active replication to viral latency (HBeAg seroconversion) usually leads to remission of the disease. alpha-Interferon (IFN) therapy induces HBeAg seroconversion in about one-third of the patients, thus leaving the majority of patients with persistent disease. Eighteen chronic hepatitis B patients who did not respond (HBeAg seroconversion and clearance of HBV-DNA) to an initial 16-week course of IFN subsequently received IFN again after at least 6 months of no therapy. The repeated therapy consisted of 1.5-5 MU lymphoblastoid IFN daily for 16 weeks. Treatment effects were monitored by quantitative measurement of HBeAg and HBV-DNA. To analyze whether the results were related to patient characteristics known to affect the response to initial treatment, a predicted response rate, based on pre-treatment factors, was determined. After a follow-up of 52 weeks, 2 of the 18 patients (11%) had responded to therapy. Two additional patients became HBV-DNA-negative with sustained HBeAg positivity. All patients remained HBsAg-positive. According to the pre-treatment parameters, a response was predicted for 9 of the 18 patients (50%). This predicted response rate was significantly higher than the actual response rate (p = 0.03). In conclusion, this pilot study with moderate dosages of IFN suggests that the HBeAg seroconversion rate after repeated IFN treatment is low for previous non-responders and probably is not related to important clinical characteristics that influence the response to initial IFN treatment. A large controlled trial with higher doses of IFN is desirable to further evaluate the benefits of retreatment.

Immunoglobulin M antibody to hepatitis C virus during interferon therapy for chronic hepatitis C

Testing for immunoglobulin (Ig) M antibody to hepatitis C virus (anti-HCV) as a predictive factor of therapeutic response to recombinant interferon alfa (rIFN-alpha) in chronic hepatitis C was evaluated in 122 patients with IgG anti-HCV. IgM anti-HCV was present in the pretreatment sample of 88% of patients who responded to treatment, including 20 of 21 (95%) long-term responders and 24 of 29 (83%) responders who had relapses after cessation of therapy. In contrast, IgM anti-HCV was present in only 23 of 39 (59%) nonresponders and 22 of 33 (66%) untreated controls (P less than 0.05). The number of cases with detectable IgM anti-HCV tended to decrease in responder patients, which was more evident for complete responders (42%) than for responders who relapsed (72%). During follow-up, the antibody became undetectable in the majority of long-term responders (28% were still IgM anti-HCV positive) but remained detectable in 69% of responders who relapsed (P less than 0.05). No special changes were noted in nonresponder or control patients. Thus, testing for IgM anti-HCV may help to identify a subset of patients who will benefit from rIFN-alpha therapy in chronic hepatitis C.

Effects of alpha-interferon on gamma-interferon production of peripheral blood mononuclear cells in hepatitis B virus carriers

We studied gamma-interferon production of phytohemagglutinin-stimulated peripheral blood mononuclear cells in response to alpha-interferon in hepatitis B virus carriers and healthy individuals. The magnitude of gamma-interferon production was significantly higher in patients with anti-HBe antibody than in patients with HBe antigen and healthy individuals. Furthermore, alpha-interferon augmented the production of gamma-interferon of peripheral blood mononuclear cells from patients with active liver injury [serum alanine aminotransferase (ALT), greater than 40 U/L], but not that from patients with inactive liver injury (serum ALT, less than 40 U/L) or healthy individuals. These results suggested that alpha-interferon could enhance the cellular immune response against hepatitis B virus by augmenting the endogenous production of gamma-interferon in patients with active liver injury, implying that the responsiveness to alpha-interferon might be responsible for liver cell injury.

Peripheral blood lymphocyte subsets in patients with chronic hepatitis C--effects of interferon treatment

Thirty-three patients with chronic hepatitis non-A, non-B/C were included in a randomized controlled study of recombinant alpha-2b interferon treatment 3 MU three times weekly for 36 weeks. In lysed whole blood, lymphocyte subpopulations were enumerated by flow cytometry detecting fluorescein or phycoerytrin conjugated monoclonal antibodies directed against seven different epitopes. Patients with chronic active hepatitis were significantly older than patients with chronic persistent hepatitis (p less than 0.05). Before treatment, the proportions of different subsets of lymphocytes were within the normal reference values and the CD4/CD8 ratio was also normal. No increased activation of T-cells was noticed. Patients over 50 years of age, however, had a significantly increased (p less than 0.01) proportion of HLA-DR+ lymphocytes, mainly B-cells. Treatment decreased the absolute number of peripheral blood leukocytes and lymphocytes. There was also a significant decline in the proportion of CD8+ lymphocytes and NK-cells, and a significant increase in the proportion HLA-DR+ cells and of the CD4/CD8 ratio. The increased proportion of HLA-DR+ cells, however, did not reflect peripheral T-cell activation; instead, it was due to increasing B lymphocyte numbers.

Transient immunoglobulin M antibody response to hepatitis C virus capsid antigen in posttransfusion hepatitis C: putative serological marker for acute viral infection

The development of serological assays for hepatitis C virus (HCV) has made specific diagnosis possible. However, markers useful in indicating acute-phase HCV infection have not been identified. By an immunoblotting method, we characterized the IgM and IgG antibody response against HCV capsid antigen in patients with HCV infection. Among 88% of patients with acute posttransfusion hepatitis C recruited in a prospective study, there was a transient IgM antibody response. The IgM antibody appeared shortly after onset of hepatitis (average 3.7 weeks), persisted for several months (average 18 weeks), and then disappeared. In contrast, the IgG antibody persisted long-term once it appeared. Among patients with chronic hepatitis C with milder disease activities (serum aminotransferase increase above normal levels of less than 4-fold), the IgM antibody was negative in the majority (72%). In those with acute exacerbations (aminotransferase increase of greater than 10-fold), about 55% were negative for the IgM antibody. The reactivity of the IgM antibody in the rest was weaker or became negative upon further dilution of serum. The results suggest that IgM anti-capsid antibody may serve as a marker indicating acute or active HCV infection.