Immunogenicity of a 'pre-S2 plus S' hepatitis B vaccine in healthy adults

The product of the pre-S plus S gene of hepatitis B virus appears to be more immunogenic in mice than the S-gene product (HBsAg) alone. Therefore, we tested the immunogenicity in healthy adults of a hepatitis B vaccine containing the 'middle protein' gene product of pre-S2 plus S (pre-S vaccine). We compared the immunogenicity of three doses of the pre-S vaccine with that of a commercially available recombinant hepatitis B vaccine (Recombivax-HB); 87 seronegative adults were randomized to receive 12 micrograms (group 1), 24 micrograms (group 2), or 48 micrograms (group 3) of the pre-S vaccine or 10 micrograms of Recombivax-HB (group 4) by deltoid injection at 0, 1 and 6 months. Antibody to HBsAg (anti-HBs) appeared after booster vaccination in > or = 94% of vaccinees. Immunogenicity was best in recipients of 48 micrograms of the pre-S vaccine and Recombivax-HB, and geometric mean titres (GMT) for the pre-S vaccine were higher than those for Recombivax-HB only at the pre-S vaccine dose of 48 micrograms (group 3). Antibody to pre-S2 developed in 75% of the pre-S2 vaccine recipients (not in Recombivax-HB recipients) within 7 months. These findings indicate that the pre-S vaccine is immunogenic in healthy adults but that a dose of 48 micrograms of the current formulation is required to equal or exceed the immunogenicity of currently available, recombinant S-only vaccine. Studies in non-responders to S-only vaccines will be necessary to define an immunological advantage of the pre-S vaccines, and additional assessments will be necessary to determine whether anti-pre-S2 enhances protective efficacy.

Clinical predictors of response to recombinant interferon-alpha treatment in patients with chronic non-A, non-B hepatitis (hepatitis C). The Hepatitis Interventional Therapy Group

Chronic non-A, non-B hepatitis (NANBH) is a common and often progressive liver disease. Based on current serological tests, hepatitis C virus (HCV) infection is responsible for most cases. Interferon-alpha (IFN) treatment at a dose of 3 x 10(6) units given three times per week for 24 weeks has been shown to be effective in normalizing serum alanine aminotransferase (ALT) levels and reducing hepatic inflammation in approximately 40% of these patients. The purpose of this study was to identify pretreatment characteristics in patients with chronic hepatitis C(CH-C) which would best predict a favourable response to IFN treatment (normalization of serum ALT). One hundred and sixty-three adult patients who had participated in a large multicentre treatment trial were included in the study group; 84 had been treated with 3 x 10(6) units of recombinant IFN-alpha-2b (rIFN) subcutaneously three times per week for 24 weeks and 79 patients had been treated with 1 x 10(6) units rIFN in the same dosage schedule. Forty-one pretreatment historical, clinical, laboratory and histological variables were evaluated. In addition, early biochemical improvement during treatment was evaluated as a predictor of ultimate response. Univariate analysis identified six variables (dose, dose m-2, weight, body surface area, ongoing ethanol use, white blood cell count and the presence of symptoms) as potential predictors of response (two-tailed, P < 0.15). By multivariate analysis, however, only the 3 x 10(6) dose of rIFN was independently predictive of response (P < 0.01). When the analysis of response was confined to those patients who received treatment with 3 x 10(6) units of rIFN, seven variables [body weight, surface area, dose m-2, current ethanol use, serum albumin and the presence of chronic persistent hepatitis (CPH) on entry liver biopsy] were more frequent in patients who responded to therapy. In a multivariate model, only CPH and body weight predicted an increased likelihood of response (P < 0.01). However, the model was not a sensitive predictor of response as only 18% of the study group had CPH on liver biopsy. A decrease in serum ALT levels within the first 12-16 weeks of rIFN treatment was found to be the strongest indicator of an ultimate response to treatment. Thus, assessment of early response to IFN treatment is the only practical means of predicting complete response and avoiding prolonged and unnecessary therapy in those with little chance of response.

Assessing health-related quality of life in chronic hepatitis C using the Sickness Impact Profile

In a randomized, controlled trial that demonstrated the efficacy of interferon alfa-2b 3 million units three times a week for 24 weeks in controlling chronic hepatitic C (non-A, non-B), the Sickness Impact Profile (SIP) was used to evaluate the impact of disease and treatment on health-related quality of life (HRQOL). The SIP was self-administered by 160 patients before treatment, at the end of treatment, and at the study endpoint. Before treatment, patients with chronic hepatitis C scored significantly (P < 0.05) higher (worse) than an historical control group of the general population in mean total SIP score and in all categories except eating. The highest degree of impairment was observed in the work, sleep and rest, and recreation and pastimes categories. After treatment, patients who received interferon alfa-2b had significant (P < or = 0.05) improvement in work, sleep and rest, and recreation and pastimes scores. Numerical improvement was observed in total score, physical and psychosocial dimension scores, and most individual category scores. Mean SIP scores were unchanged or slightly worsened in untreated control patients. In responders (patients with improvement in serum alanine aminotransferase levels), the largest improvement was seen in work scores. The SIP appears to be a reliable and valid instrument for describing the impact of chronic hepatitis C on HRQOL but lacks disease-specificity and the ability to reflect clinically relevant changes. Thus the SIP is not the best instrument to evaluate the HRQOL effects of treatment with interferon alfa-2b in patients with chronic hepatitis C.

Hepatitis B virus precore mutation and fulminant hepatitis in the United States. A polymerase chain reaction-based assay for the detection of specific mutation

Hepatitis B virus (HBV) variants with precore mutation(s) resulting in the absence of HBeAg production have been associated with the occurrence of fulminant hepatitis in Japan, Israel, and southern Europe, where the prevalence of this HBV strain appears common. In areas such as United States, where HBV infection is not endemic, the role of this mutant virus in fulminant hepatitis is unknown. We developed an amplification refractory mutation detection system to detect specifically the presence of the G to A mutation at nucleotide position 1898, which is the most frequently observed mutation resulting in a precore stop codon. In addition, this method provided a quantitative measurement of the relative ratio of one strain to the other. Using this system, we tested HBV strains for the presence of the stop codon mutation in sera from 40 cases of fulminant hepatitis B occurring in the United States. Serum HBV DNAs from 28 patients were analyzed successfully. A mixture of wild-type and mutant strains in various ratios were observed in 15 patients, wild type exclusively in 11, and mutant exclusively in 2. Four of these patients had undergone liver transplantation for HBV-associated cirrhosis and developed fulminant HBV-associated hepatitis after transplantation. Pre- and posttransplant serum samples from one patient were analyzed: a mixture of wild-type and mutant HBV strains was detected in both samples. Our study demonstrated that both wild-type and mutant HBV strains are associated with fulminant hepatitis, and that in some patients in the United States, factors other than precore mutations contribute to the development of fulminant hepatitis.

Cytomegalovirus immune globulin prophylaxis in liver transplantation. A randomized, double-blind, placebo-controlled trial

OBJECTIVE

To study the effect of cytomegalovirus immune globulin (CMVIG) on prevention of cytomegalovirus (CMV) disease and its complications in patients receiving liver transplants.

DESIGN

Randomized, multicenter, placebo-controlled, double-blind trial.

SETTING

Four university-affiliated transplant centers in Boston (Boston Center for Liver Transplantation).

PATIENTS

One hundred forty-one liver transplant recipients completed the study.

INTERVENTION

CMVIG or placebo (1% albumin) given in a dose of 150 mg/kg body weight within 72 hours of the transplant, then at weeks 2, 4, 6, and 8, and at 100 mg/kg at weeks 12 and 16.

MEASUREMENTS

Patients were observed for 1 year after transplantation for the development of CMV infection, disease, pneumonia, as well as for opportunistic fungal infections, graft survival, and mortality. Weekly cultures were taken of urine, buffy coat, and throat wash for CMV for 2 months, then monthly, and at any clinical illness.

RESULTS

Using a Cox proportional hazards model, CMVIG was shown to reduce severe CMV-associated disease (multi-organ CMV disease, CMV pneumonia, or invasive fungal disease associated with CMV infection) from 26% to 12% (relative risk, 0.39; 95% CI, 0.17 to 0.89). When we controlled for the use of monoclonal antibodies to T cells (OKT3), CMVIG use was still protective (relative risk, 0.39; CI, 0.17 to 0.90). Rates of CMV disease were reduced from 31% to 19% (relative risk, 0.56; CI, 0.3 to 1.1) in CMVIG recipients although no effect on rates of CMV infection, graft survival, or patient survival at 1 year were shown. When we controlled for the urgency of transplantation and OKT3 use, a reduction in CMV disease (relative risk, 0.22; CI, 0.06 to 0.81) was shown for globulin recipients for all serologic groups except for the highest risk group (the CMV-seropositive donor, CMV-seronegative group).

CONCLUSION

CMVIG reduced the rate of severe CMV-associated disease in patients undergoing orthotopic liver transplantation. No effect of CMVIG on CMV donor-positive, recipient-negative liver transplant recipients was shown, suggesting a need for additional prophylactic strategies.

Pathological diagnosis of chronic hepatitis C: a multicenter comparative study with chronic hepatitis B. The Hepatitis Interventional Therapy Group

BACKGROUND

Hepatic histological responses described in hepatitis C virus (HCV) infection include bile duct damage, lymphoid follicles and/or aggregates in portal tracts, large- and small-droplet fat, Mallory body-like material in hepatocytes, liver cell dysplasia and multinucleation, and activation of sinusoidal inflammatory cells. The specificity of these lesions for HCV infection is uncertain.

METHODS

In two multicenter trials of recombinant interferon alfa therapy for chronic hepatitis C and B, the frequency of these eight lesions in pretherapy and posttherapy liver biopsy specimens was examined to determine the set of features, if any, that distinguishes HCV from hepatitis B virus (HBV) infection. The lesions were scored in 317 HCV biopsy specimens and 299 HBV specimens.

RESULTS

Stepwise logistic regression determined a set of three features more likely to be seen in HCV than in HBV infection: bile duct damage [odds ratio (OR), 4.7; 95% confidence interval (Cl), 1.8-12.3], lymphoid follicles and/or aggregates (OR, 2.4; 95% Cl, 1.2-4.7), and large-droplet fat (OR, 2.4; 95% Cl, 1.4-4.1). A fourth lesion, Mallory body-like material, was seen only in HCV biopsy specimens (OR, 71.6; 95% Cl, 4.4-996.1).

CONCLUSIONS

These four histological lesions are useful pathological parameters in the diagnosis of liver disease caused by HCV.

Prevalence and incidence of viral hepatitis in health workers in the prehepatitis B vaccination era

To assess the impact of hepatitis B virus on health workers, the authors studied baseline prevalences of hepatitis B serologic markers and undertook prospective surveillance to assess hepatitis B attack rates in 837 health workers and 994 blood-donor controls between 1977 and 1982, before the introduction of hepatitis B vaccine. The baseline prevalence of all hepatitis B markers was 14% in health workers and 6% in controls (p < 0.001); exposure to hepatitis B virus was related to the intensity of blood exposure and its duration. In contrast, the frequency of exposure to hepatitis A virus, a nonblood-borne agent, was lower in health workers (11%) than in controls (16%) (p < 0.01) and increased as a function of age. Multivariate logistic regression analysis identified occupational categories with frequent blood contact, rather than duration of exposure, as being the dominant variable for exposure to hepatitis B virus; for hepatitis A virus exposure, age was the most significant variable. Among health workers susceptible to hepatitis B, the incidence of new definite hepatitis B infections was 1.0% per year in 362 health workers (804 person-years of follow-up observation) with frequent blood contact versus 0% per year in 258 health workers (534 person-years of observation) with limited blood contact (p = 0.017). For definite plus probable cases combined, the incidence of new hepatitis B infections was 1.5% per year versus 0.2% per year for the groups with frequent and limited blood exposures, respectively (p = 0.0013). There were no new cases of hepatitis A or B or seroconversions in controls and only one case of hepatitis A acquired outside the hospital by a health worker. These data confirm the high prevalence of hepatitis B exposure and document in a prospective study the high incidence over time of new hepatitis B virus infections in health workers unprotected by vaccination. Such findings reiterate the need for aggressive vaccination programs in health workers exposed to blood.

The high-risk liver allograft recipient. Should allocation policy consider outcome?

The Boston Center for Liver Transplantation has accumulated one of the larger series of liver allograft recipients. This review has provided an opportunity to examine recent pronouncements by Medicare regarding patient selection and survival and to question whether the current allocation scheme best utilizes a scarce supply of donor liver allografts. Patients with primary biliary cirrhosis, sclerosing cholangitis, and metabolic derangements have enjoyed excellent survival: in aggregate, 78.9% at 1 year. In contrast, patients suffering from acute hepatic failure, patients requiring life support, or patients with primary graft failure who need a second liver transplant did poorly compared with other recipient groups: 45% 1-year survival. This center's experience reflects a more realistic expectation of patient survival because it considers the high-risk recipient by diagnosis and urgency status. This study also suggests that assessment of outcome should be a component of allocation planning in the future.

Role of hepatitis C virus in non-B chronic liver disease

To assess the contribution of the recently identified hepatitis C virus to chronic liver diseases of unknown cause and chronic hepatitis attributed by exclusion to non-A, non-B hepatitis, we tested for antibody to hepatitis C in hepatitis B surface antigen-negative patients with a spectrum of chronic liver diseases. Antibody to hepatitis C virus, a marker of hepatitis C infection, was detected with a first-generation radioimmunoassay at the following frequencies in the following patient groups: 69% of transfusion-associated non-A, non-B hepatitis; 53% of non-transfusion-associated non-A, non-B hepatitis; 26% of hepatitis B surface antigen-negative hepatocellular carcinoma; 8% of cryptogenic cirrhosis; 5% to 7% of autoimmune chronic liver diseases; 19% of patients with miscellaneous types of chronic liver disease; and 0.67% of healthy controls. Among non-transfusion-associated cases, 81% with a history of intravenous drug use but only 18% with occupational exposure as health workers had antibody to hepatitis C virus. Among cases of hepatocellular carcinoma, 63% of Japanese patients but only 11% of American patients had evidence of hepatitis C infection. Comparison in a subgroup of 79 serum samples of a second-generation radioimmunoassay with the first-generation assay demonstrated a 12% increase in antibody frequency from 30% to 42%. We conclude that hepatitis C plays a substantial role in transfusion-associated and non-transfusion-associated non-A, non-B hepatitis as well as in hepatocellular carcinoma, especially in Japan, a limited role in cryptogenic cirrhosis, and essentially no role in autoimmune chronic liver diseases. Application of more sensitive immunoassays will increase the frequency of antibody seropositivity in all subgroups, but relative distinctions among risk groups are likely to remain.

A randomized, controlled trial of interferon alfa-2b alone and after prednisone withdrawal for the treatment of chronic hepatitis B. The Hepatitis Interventional Therapy Group

BACKGROUND AND METHODS

Chronic hepatitis B is a common and often progressive liver disorder for which there is no accepted therapy. To assess the efficacy of treatment with interferon, we randomly assigned patients with chronic hepatitis B to one of the following regimens: prednisone for 6 weeks followed by 5 million units of recombinant interferon alfa-2b daily for 16 weeks; placebo followed by 5 million units of interferon daily for 16 weeks; placebo followed by 1 million units of interferon daily for 16 weeks; or observation with no treatment.

RESULTS

Hepatitis B e antigen and hepatitis B viral DNA disappeared from serum significantly more often in the patients given prednisone plus interferon (16 of 44 patients, or 36 percent) or 5 million units of interferon alone (15 of 41; 37 percent) than in the untreated controls (3 of 43; 7 percent; P less than 0.001); the difference between those given 1 million units of interferon (7 of 41; 17 percent) and the controls was not significant. The strongest independent predictor of a response to treatment was the amount of hepatitis B viral DNA in serum at entry (P less than 0.0001). Of the 38 patients who responded to interferon, 33 (87 percent) had normal serum aminotransferase levels after therapy; 11 patients who responded (29 percent), but no controls, lost the hepatitis B surface antigen. Blinded histologic assessment revealed a significant improvement in periportal necrosis in the treated patients (P = 0.03).

CONCLUSIONS

In chronic hepatitis B, treatment with interferon alfa-2b (5 million units per day for 16 weeks) was effective in inducing a sustained loss of viral replication and achieving remission, assessed biochemically and histologically, in over a third of patients. Moreover, in about 10 percent of the patients treated with interferon, hepatitis B surface antigen disappeared from serum.

Prevalence of hepatitis C virus antibody in a cohort of hemophilia patients

One hundred thirty-one patients followed at the New England Hemophilia Center (Worcester, MA) were tested for antibody to hepatitis C virus (HCV). All but two had used factor concentrate that had not undergone viral inactivation; two patients had used only cryoprecipitate. The overall prevalence of HCV antibody positivity was 76.3%. There was no significant difference in age or the amount of non-heat-treated factor concentrate used between the group that was HCV antibody positive and negative. There was also no significant difference between aminotransferase levels in the two groups. There was a positive association between HCV antibody and the presence of antibody to hepatitis B core antigen and antibody to human immunodeficiency virus. A group of 31 patients were tested twice for HCV antibody at intervals of 35 to 71 months. In this subset, 25 were repeatedly seropositive, 4 were repeatedly seronegative, and 2 went from seropositive to seronegative. These data confirm the previous impression that non-A, non-B hepatitis is a major sequela to the use of pooled coagulation factor concentrates. HCV infection may account for most of the chronic liver disease observed in this population. Anti-HCV testing of plasma donors and improved methods of viral inactivation should prevent new cases from developing.

Treatment of chronic hepatitis C with recombinant interferon alfa. A multicenter randomized, controlled trial

Chronic hepatitis C (non-A, non-B hepatitis) is a common and often progressive viral liver disease. To assess the efficacy of therapy with the antiviral agent interferon alfa, we randomly assigned 166 patients with chronic hepatitis C to treatment with either 3 million or 1 million units of recombinant interferon alfa three times weekly for 24 weeks, or to no treatment. The probability of normalization or near normalization of the serum alanine aminotransferase levels after six months of interferon therapy was 46 percent in patients treated with 3 million units of interferon (P less than 0.001) and 28 percent in those treated with 1 million units (P less than 0.02), but only 8 percent in untreated patients. The serum alanine aminotransferase level became completely normal in 22 of the 26 patients (85 percent) who responded to treatment with 3 million units of interferon and 9 of the 16 patients (56 percent) who responded to treatment with 1 million units. The patients who received 3 million units of interferon had histologic improvement because of the regression of lobular and periportal inflammation. Relapse within six months after the completion of treatment occurred in 51 percent of the patients treated with 3 million units of interferon and 44 percent of those treated with 1 million units. We conclude that a 24-week course of interferon therapy is effective in controlling disease activity in many patients with hepatitis C, although relapse after the cessation of treatment is common.

Genetic prediction of nonresponse to hepatitis B vaccine

In previous studies of the antibody response to hepatitis B vaccine in 598 subjects who received a full course of vaccination, we observed a bimodal response, with about 14 percent producing less than approximately 1000 radioimmunoassay (RIA) units. An analysis of the major histocompatibility complex (MHC) HLA and complement types of 20 of the subjects with the lowest responses indicated a greater-than-expected number of homozygotes for the extended or fixed MHC haplotype [HLA-B8, SC01, DR3]. This finding suggested that the lack of a normal response was a recessive MHC-linked trait. In this study, we prospectively vaccinated five homozygotes and nine heterozygotes for this haplotype in the expectation that the homozygotes would produce much lower levels of antibody than the heterozygotes. When the antibody response was assessed two months after the third injection, four of the five homozygotes had produced very low levels (approximately 1000 units or less) of antibody (mean, 467 RIA units; range, less than 8 to 1266), whereas all nine heterozygotes produced more than 2500 RIA units (mean, 15,608; range, 2655 to 28,900) (P less than 0.01). We conclude that the usual response to hepatitis B surface antigen is due to the presence of a dominant immune-response gene in the MHC and that a low response is due to the absence of such a gene and the presence on both chromosomes of MHC haplotypes (such as [HLA-B8, SC01, DR3]) that indicate such a response.

An assay for circulating antibodies to a major etiologic virus of human non-A, non-B hepatitis

A specific assay has been developed for a blood-borne non-A, non-B hepatitis (NANBH) virus in which a polypeptide synthesized in recombinant yeast clones of the hepatitis C virus (HCV) is used to capture circulating viral antibodies. HCV antibodies were detected in six of seven human sera that were shown previously to transmit NANBH to chimpanzees. Assays of ten blood transfusions in the United States that resulted in chronic NANBH revealed that there was at least one positive blood donor in nine of these cases and that all ten recipients seroconverted during their illnesses. About 80 percent of chronic, post-transfusion NANBH (PT-NANBH) patients from Italy and Japan had circulating HCV antibody; a much lower frequency (15 percent) was observed in acute, resolving infections. In addition, 58 percent of NANBH patients from the United States with no identifiable source of parenteral exposure to the virus were also positive for HCV antibody. These data indicate that HCV is a major cause of NANBH throughout the world.

Recombinant-yeast-derived hepatitis B vaccine in healthy adults: safety and two-year immunogenicity of early investigative lots of vaccine

We tested the safety and long-term immunogenicity of two of the early investigative lots of a recombinant-yeast-derived hepatitis B vaccine in immunocompetent adults. Three 10-micrograms doses of recombinant hepatitis B vaccine (Merck Sharp & Dohme Research Laboratories, West Point, PA) were administered by deltoid intramuscular injection at time 0, 1, and 6 months to 65 seronegative adult health workers. Following a complete three-injection course, 98% of vaccinees acquired anti-HBs, 97% at levels greater than 10 mlU/ml, and 95% maintained such "protective" antibody levels at 1 year. At 2 years, 93% retained antibody, but only 68% had levels greater than 10 mlU/ml. In those who responded to vaccination by achieving any detectable level of antibody, the peak geometric mean titer of anti-HBs, measured at 9 months, was 741 +/- 6 mlU/ml; the geometric mean titer fell to 348 +/- 6 at 1 year and to 66 +/- 7 at 2 years. Side effects were trivial, and levels of yeast antibody, as measured by radioimmunoassay, were not changed from prevaccine levels. No serious adverse effects were encountered, and neither type B nor non-B hepatitis occurred in any vaccine. These findings demonstrate that the recombinant yeast hepatitis B vaccine is safe and immunogenic but that 10 micrograms of the early investigative lots of the recombinant vaccine is less immunogenic than 20 micrograms of the plasma-derived vaccine. Recipients of early investigative vaccine lots should be considered for booster vaccination with currently available, more immunogenic vaccine lots.

Cure of hemophilia A by orthotopic liver transplantation

A patient with hemophilia A and transfusion-associated end-stage chronic liver disease underwent orthotopic liver transplantation. He had no requirement for exogenous factor VIII replacement during the 27 mo he survived. Although his hemophilia was cured, he had antibodies to the human immunodeficiency virus; ultimately he died of complications arising from acquired immunodeficiency syndrome. Liver transplantation for cirrhotic hemophiliacs can free them of the need for antihemophilic-factor therapy; however, application of this approach may be limited by the high prevalence of human immunodeficiency virus infection in multitransfused hemophiliacs.

Evaluation of blood donors with elevated serum alanine aminotransferase levels

We evaluated 100 asymptomatic blood donors with serum alanine aminotransferase (ALT) levels exceeding 0.83 mu kat/L, for evidence of liver disease or risk factors for non-A, non-B hepatitis and followed serum ALT levels for another 6 months. In 92 donors completing the study, ALT elevations occurred once in 33%, intermittently in 36%, persistently in 28%. Twenty-two donors were obese, 5 had clinical and biochemical evidence of alcoholic liver disease, and 45 drank alcohol regularly; 1 had hemochromatosis, and another, myopathy. In 22 no cause for elevated serum ALT levels was found. The presence or absence of risk of acquiring hepatitis did not correlate with the pattern of ALT elevations or the identification of another cause for the elevated ALT levels. In 92 blood donors with an initially elevated ALT level, two-thirds have intermittent or persistent elevations; most approximately 20% have no apparent cause for the elevations other than possible non-A, non-B hepatitis. These findings may be helpful in counseling and following blood donors with elevated ALT levels.