Hepatitis B viral nucleotide sequences in non-A, non-B or hepatitis B virus-related chronic liver disease

Are current screening protocols for chronic hepatitis B virus infection adequate?

Chronic hepatitis B virus (HBV) infection screening usually includes only HBV surface antigen (HBsAg) testing; HBV core and surface antibody (anti-HBc, anti-HBs) assays, indicating resolved infection and immunity, are not routinely performed. Yet, serum HBV DNA is measurable in approximately 10% of HBsAg-negative/anti-HBc-positive cases, representing occult HBV infection (OBI). Patient blood samples from 2 Veterans Affairs medical center look-back investigations were screened for HBV infection using HBsAg enzyme immunoassays. Supplementary testing included anti-HBc and anti-HBs enzyme immunoassays. For anti-HBc-positive samples, HBV DNA testing was performed. Background OBI prevalence was further estimated at these 2 facilities based on HBV serology testing results from 1999-2012. Finally, a literature review was performed to determine OBI prevalence in the published literature. Of 1887 HBsAg-negative cohort patients, 98 (5.2%) were anti-HBc positive/anti-HBs negative; and 175 (9.3%), anti-HBc positive/anti-HBs positive. Six of 273 were HBV DNA positive, representing 0.3% of the total tested and 2.2% who were anti-HBc positive/anti-HBs negative or anti-HBc positive/anti-HBs positive. Among 32,229 general population veterans at these 2 sites who had any HBV testing, 4/108 (3.7%) were HBV DNA positive, none of whom were part of the cohort. In 129 publications with HBsAg-negative patients, 1817/1,209,426 (0.15%) had OBI. However, excluding blood bank studies with greater than 1000 patients, the OBI rate increased to 1800/17,893 (10%). OBI is not rare and has implications for transmission and disease detection. HBsAg testing alone is insufficient for detecting all chronic HBV infections. These findings may impact blood donation, patient HBV screening, follow-up protocols for patients assumed to have cleared the infection, and initiation of immunosuppression in patients with distant or undetected HBV.

Hepatitis B surface antigen seroclearance during chronic HBV infection

Hepatitis B surface antigen (HBsAg) seroclearance in chronic HBV infection occurs at an annual incidence of 1-2%. The long-term outcome after HBsAg seroclearance is excellent if there is no pre-existing cirrhosis or viral superinfection. For this reason, HBsAg seroclearance has attracted recent interest in both long-term studies of the natural history of HBV infection and in patients receiving antiviral therapy. Here, we review a diverse range of studies investigating spontaneous HBsAg seroclearance in varied groups of patients and consider the many predictive factors - of both viral and host origin - for seroclearance. Studies to assess the effects of antiviral therapy, and in particular interferon treatment, are also discussed together with virological, biochemical and histological profiles following HBsAg seroclearance and the long-term outcomes.

Virological profiles in patients with chronic hepatitis C and overt or occult HBV infection

OBJECTIVES

The virological profiles of hepatitis B and C viruses (HBV and HCV) and their interplay in cases of coinfection are undefined. A suppressed and occult HBV infection may occur in hepatitis B surface antigen (HBsAg) negative patients with chronic hepatitis C. The HCV core protein is able to inhibit HBV "in vitro," and serines at positions 99 and 116 are essential for such inhibition. We aimed to assess the HBV and HCV virological profiles in cases of coinfection and to evaluate the relationship between HCV core gene variability and HBV activity.

METHODS

Eighty-two anti-HCV positive patients were examined: 35 cases were HBsAg positive, 24 were HBsAg negative with "occult" HBV infection, and 23 were HBV negative. HBV and HCV viremia levels were evaluated in all cases. HCV genomic region coding for the aminoacid sequence 99-116 of core protein was amplified and sequenced in all HCV RNA positive cases. The entire core gene was amplified and sequenced in three randomly selected cases.

RESULTS

Serum HCV RNA was detected in all cases but 13, all HBsAg positive individuals; HCV viremia levels of the other 22 HBsAg positive subjects were similar to those detected in HBsAg negative patients with or without occult HBV infection. Among the 35 HBsAg positive patients both HBV DNA and HCV RNA were detected in five cases, HCV RNA alone in 17, and HBV DNA alone in six, whereas seven cases had undetectable levels of both viruses. Sequencing analyses showed that the HCV core gene was highly preserved in all patients.

CONCLUSION

A wide spectrum of HCV and HBV virological patterns may occur in a case of coinfection. HCV core variability is not related to HBV activity "in vivo."

Occult hepatitis B virus infection

Many studies have shown that hepatitis B virus infection may also occur in hepatitis B surface antigen-negative patients. This occult infection has been identified both in patients with cryptogenic liver disease and in patients with hepatitis C virus-related chronic hepatitis, and much evidence suggests that it may be a risk factor of hepatocellular carcinoma development. However several aspects of this occult infection remain unclear such as its prevalence and the factor(s) involved in the lack of circulating hepatitis B surface antigen. Moreover, it is uncertain whether the occult hepatitis B virus infection may contribute to chronic liver damage, considering that it is usually associated with a suppressed viral replication. Evidence and hypotheses concerning this fascinating field of bio-medical research are reviewed.

Identification of a novel surface mutant of hepatitis B virus in a seronegative chronic liver disease patient

Hepatitis B virus (HBV) with mutations in the envelope proteins can emerge during natural infections, vaccinations or interferon therapy and appears occasionally to escape virus elimination or detection. The implications of such mutations at the molecular level are often obscure. We report the identification of a new surface mutant of HBV. This mutant was identified, and isolated from a chronic liver disease patient, negative for HBsAg as well as other serological markers but positive for HBV DNA. Several mutations were observed in the surface antigen gene out of which a Thr118-Ala118 change was predicted to have a destabilizing effect on the structural integrity of the 'a' determinant and also alter the antigenicity profile of the mutant HBsAg. Besides a RNA hairpin loop was predicted for the transcript generated by the small surface protein of this mutant, which could have an inhibitory effect at the translational level. These observations thus indicate that mutations in the surface gene could lead to a considerable decrease or complete absence of properly folded surface antigen which in turn could explain the absence of reactive HBsAg in the serum of the patient.

Highly sensitive hepatitis B surface antigen detection by measuring stable nitroxide radical formation with ESR spectroscopy

In areas where hepatitis B virus (HBV) is prevalent, HBV carriers negative for hepatitis B surface antigen (HbsAg) by enzyme-linked immunosorbent assay (ELISA) have been reported. Moreover, even after screening donor blood for HbsAg and hepatitis B core antibody (HBcAb), post-transfusion hepatitis B continues to occur, though with a decreasing frequency. Therefore, screening tests far more sensitive for detecting HBsAg than those currently available are needed. We developed a highly sensitive method for HBsAg detection. It is based on the recognition of peroxidase activity through measuring the formation of stable nitroxide radical with electron spin resonance (ESR) spectroscopy in the presence of hydrogen peroxide, p-acetamidophenol (p-AP), and 4-hydrazonomethyl-1-hydroxy-2,2,5,5,-tetramethyl-3-imidazoline-3-o xide (HHTIO). A cut-off value was established by testing of 186 healthy adults and 50 HBsAg-positive individuals. The signal to noise (S/N) ratio of less than 1.488 obtained by ESR spectroscopy was considered to be negative and more than 2.181, positive. The p-AP/HHTIO method was found to be 10 times more sensitive than the standard ELISA and reproducibility was excellent. Additional investigations were made on the HBsAg levels in the serum from 26 healthy subjects, in whom cut-off index levels on ELISA were negative but relatively high (range: 0.6 to 1.0); and on 15 patients with non B non C hepatitis. Three of 26 cases and 3 of 15 with non B non C hepatitis were judged to be HBsAg positive. Of these, 5 were found to be positive for HBV DNA by polymerase chain reaction (PCR). It was shown in this study that the p-AP/HHTIO method is practical and useful in screening HBV carriers because of the sensitivity in HBsAg detection, which is comparable to PCR analysis.

Presence of hepatitis B and C viral genomes in US blood donors as detected by polymerase chain reaction amplification

Hepatitis C virus (HCV) represents a major cause of posttransfusion hepatitis worldwide. Posttransfusion hepatitis associated with hepatitis B virus (HBV) continues to occur. HBsAg-negative donor sera from the Rhode Island Blood Center between 1987 and 1988 were screened using more sensitive techniques to assess the prevalence of low level HBV infection. Group I consists of 866 healthy blood donors without HBV serologic markers, group II consists of 377 donors with ALT elevations (> 45 IU/L), group II consists of 148 donors positive for anti-HBc, and group IV consists of eight donors positive for both surrogate markers. A sensitive monoclonal immunoradiometric assay (M-IRMA) was employed for detection of HBsAg-associated epitopes (detection limit of 20 pg/ml) in serum. A subset of sera were analyzed for the presence of HBV DNA using the method of anti-HBs capture of HBV related virions in serum followed by polymerase chain reaction (PCR) amplification. Using these techniques, 0.8% and 1.7% of donors were positive for HBsAg and HBV DNA respectively in group I. In contrast, 0.9% and 9.5% in group II and 0.7% and 18.1% in group III were positive, respectively. There were eight donors with both ALT elevation and anti-HBc; and four (50%) of these were positive for HBV DNA. In the group with anti-HBc, the majority (80%) of donors with HBV DNA had either no or low (signal to noise ratio < 10) anti-HBs titer. Using anti-HCV testing and reverse transcription-PCR for detection of HCV genomes, we detected evidence of HCV infection in nine of the 49 donors with low level HBV DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Markers of hepatitis C virus infection in Sardinian blood donors: relationship with alanine aminotransferase levels

Serum samples from 1,765 consecutive Sardinian blood donors, negative for hepatitis B surface antigen (HBsAg) and for antibodies to human immunodeficiency virus (HIV) (anti-HIV), were evaluated for the presence of antibodies to hepatitis C virus (anti-HCV) by second-generation ELISA. Anti-HCV was detected in 25 (1.45%) of the 1,765 donors examined. Anti-HCV was found in 15 of the 1,690 (0.9%) donors with normal alanine aminotransferase (ALT) and in 10 of the 75 (13%) donors with elevated ALT (P < 0.0001). Of the 15 anti-HCV-positive donors with normal ALT, only five (33%) were confirmed to be positive by second-generation RIBA, six (40%) were indeterminate, while four (27%) were RIBA negative. HCV RNA, as detected by polymerase chain reaction (PCR) using a set of primers from the 5'-noncoding region, was found in six of the 15 (40%) donors with normal ALT, including five RIBA positive and one indeterminant. Of the 10 anti-HCV-positive donors with elevated ALT, all were RIBA positive and eight (80%) had detectable HCV RNA. Thus, among ELISA-reactive donors, those with elevated ALT had a significantly higher probability of being positive for second-generation RIBA and HCV RNA compared to those with normal ALT levels (P = 0.028). None of the 65 donors with elevated ALT but negative for anti-HCV by ELISA had detectable serum HCV RNA, as compared to eight of 10 anti-HCV ELISA-positive donors (P < 0.0001). However, although negative for HBsAg, 12 of the 65 (18%) had serum HBV DNA by PCR.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequence analysis of hepatitis B virus DNA in immunologically negative infection

It was previously demonstrated that the serum of some patients without immunological evidence of HBV infection contains the virus. Here we demonstrated by sequence analysis that the serum of such a patient contained a mixed HBV population. In comparison with HBV genomes of different genotypes twenty-two nucleotide variations were found in all clones sequenced in parallel. One nucleotide variation was identified within the enhancer I. Twelve of the twenty-two nucleotide variations caused altogether fifteen changes of amino acid sequence in known or predicted viral proteins. The proteins of the P open reading frame, which are most important for viral replication, were affected by nine amino acid substitutions. Three amino acid substitutions concerned the product of the X gene, a transcriptional transactivator of various viral and cellular promoters. Three mutations were only observed in some of the clones. One point mutation affected the direct repeats of the enhancer II. It occurred together with an 8 bp-deletion involving the C promoter region and the X gene. The third mutation was a single insertion, causing a fusion of the X and C gene. One or several of the identified mutations could be responsible for the diminished rate of replication and consequently for the low-titred, immunologically negative HBV infection.

Geographical variation in prevalence of hepatitis B virus DNA in HBsAg negative patients

AIMS--To study the geographical variation of the prevalence of hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg) negative subjects. METHODS--A nested polymerase chain reaction (PCR) assay was used to amplify the core region of HBV. The assay was able to detect 10 molecules of a full length HBV plasmid. RESULTS--When applied to HBsAg negative paraffin wax embedded liver samples from Italy, Hong Kong, and the United Kingdom, a geographical variation in the prevalence of HBV-DNA positivity was noted. Two of 18 (11%) of Italian samples and 2/29 (6.9%) of Hong Kong samples were positive for HBV-DNA while none of the 70 cases from the United Kingdom was positive by nested PCR. Contamination by plasmid DNA was excluded using a novel method based on heteroduplex formation. One HBV-DNA positive case had idiopathic chronic active hepatitis, but the diagnoses in the other three HBV-DNA positive cases did not suggest any aetiological connection between HBV-DNA positivity and liver pathology. CONCLUSIONS--HBV-DNA could be detected in the liver tissues of a proportion of HBsAg negative subjects. The prevalence of such cases is related to the endemic rate of a geographical region. The use of HBV PCR on paraffin wax embedded tissues will be valuable for future studies on the molecular epidemiology of HBV.

Hepatitis B virus DNA in serum and liver is commonly found in Chinese patients with chronic liver disease despite the presence of antibodies to HBsAg

Sera from 410 patients from the Wuhan area in the central part of China with the diagnosis of chronic liver disease were analyzed for markers of hepatitis B, C and D virus infections. All sera, plus liver biopsy specimens from 188 of the patients, were also tested for hepatitis B virus DNA by polymerase chain reaction. Sixty-eight percent were HBsAg positive in serum, whereas 29% showed markers of past hepatitis B virus infection. Hepatitis B virus DNA was detected in all HBeAg-positive sera but also in 58% of patients with HBe antibody. In the liver specimens of the corresponding patient groups, 97% and 78%, respectively, were hepatitis B virus DNA positive. However, more noteworthy was that of the HBsAg-negative/HBs-antibody positive patients 30% had detectable hepatitis B virus DNA in serum and 32% had hepatitis B virus DNA in liver tissue, whereas in a control group of healthy blood donors, of which 90% had HBs antibody, none was hepatitis B virus DNA positive. Our results demonstrate that among patients with chronic liver disease, infections with hepatitis B virus or hepatitis B virus-related virus(es) may frequently occur without being revealed by conventional serological methods. Hepatitis C and D viruses seem to be of only minor importance in the pathogenesis of chronic liver disease in this part of China.

The efficacy of a peptide-nucleic acid solution (Reticulose) for the treatment of hepatitis A and hepatitis B--a preliminary controlled human clinical trial

To complete this preliminary study 53 patients were chosen. All patients were screened, diagnosed for Hepatitis A or Hepatitis B and separated into treatment and control groups. All of the patients selected were in the early onset stage of their infection, and diagnosed for Hepatitis A or B by appropriate laboratory tests with special attention to Anti-HAV, IGM and HepB surface Antigen to carefully differentiate those with A from those with B. The treated patients received Reticulose for a 15 day period and the control patients received placebo injections of physiological saline. Reticulose patients with Hepatitis showed positive. 18 patients with Hepatitis B and 9 patients with Hepatitis A were treated with Reticulose, compared to 17 control patients with Hepatitis B and 9 control patients with Hepatitis A treated with placebo. Based upon laboratory findings of several parameters; Prothrombin times, Serum bilirubin, white blood cell (WBC count) and clinical observations; Reticulose treated patients appeared to show significant improvement. The bilirubin levels of 83% of patients with Hepatitis B, treated with Reticulose for 15 days were in normal range in 30 days. None of the control patients were within normal range after 30 days with placebo treatment. Of Hepatitis A patients treated with Reticulose, 100% showed normal bilirubin after 30 days. Of control patients with Hepatitis A, only 22% were in normal range after 30 days. The findings in this preliminary trial lead to the conclusion that Reticulose appears to significantly reduce the recovery time and return to normal for patients with an acute episode of Hepatitis A or B. Further study is indicated.

Hepatitis B virus markers and antibodies to hepatitis C virus in Japanese patients with hepatocellular carcinoma

Sera from Japanese patients with chronic liver disease were tested for hepatitis B virus (HBV) markers and antibodies to hepatitis C virus (anti-HCV), and the results were correlated to the presence of hepatocellular carcinoma. In chronic non-A, non-B liver disease, anti-HCV prevalence was high both in patients with hepatocellular carcinoma (78/89, 88%) and without it (66/84, 79%), while previous HBV infection was more common in patients with hepatocellular carcinoma (65/89, 73%) than in those without it (46/84, 55%) (P less than 0.05). Coexistence of anti-HCV and antibodies to HBV was observed frequently in patients with hepatocellular carcinoma (56/89, 63%) compared with patients without it (39/84, 46%) (P less than 0.05). In chronic HBV carriers, anti-HCV was more common in patients with hepatocellular carcinoma (12/38, 32%) than in those without it (3/62, 5%) (P less than 0.01). These results suggest that infection with the two viruses may be a risk factor for more serious liver disease.

Detection of HBV DNA in non-A, non-B hepatic tissues using the polymerase chain reaction assay

The polymerase chain reaction (PCR) followed by Southern blotting was used to examine the presence of hepatitis B virus (HBV) DNA in non-cancerous liver tissue specimens from 22 Japanese hepatocellular carcinoma (HCC) patients, who were negative for HBV surface antigen (HBsAg). By Southern blot analysis, HBV DNA was negative in all 22 patients, but it was detected by the PCR in 8 of the 15 patients who were positive for antibodies against HBsAg or HBV core antigen. Seven patients who were negative for those antibodies were also negative for HBV DNA by the PCR. These results suggest that HBV may be involved in the etiology of the liver disease of some patients with what is presently classified as non-A, non-B hepatitis, if they are positive for HBV antibodies.

Antibodies to hepatitis B virus and hepatitis C virus in alcoholic hepatitis and cirrhosis: their prevalence and clinical relevance. The VA Cooperative Study Group (No. 119)

Patients with overt alcoholic liver disease who had participated in a multicenter therapeutic trial and subgroups of controls (i.e., alcoholic patients without liver disease and patients with neither alcoholism nor liver disease) were tested for hepatitis B virus and hepatitis C virus antibodies to determine the prevalence of these antibodies to determine the prevalence of these antibodies and any clinical association in the progression and outcome of alcoholic liver disease. Antibodies to hepatitis B (anti-HBs and/or anti-HBc) were found in 29.2% of patients with alcoholic liver disease, in 26.1% of hospitalized alcoholic patients without liver disease and in 24.2% of hospitalized nonalcoholic patients without liver disease; frequencies were not significantly different from one another. HBsAg was not evaluated because HBsAg+ patients had been excluded from the original trial. The presence of these antibody markers correlated with ethnic origin of and immunoglobulin levels in the patients. In contrast, antibody to hepatitis C, as detected by enzyme immunoassay, was positive in 27.1%, 4.8% and 3.0% of the three groups, respectively, the first differing significantly from the other two. Antibody to hepatitis C virus positivity correlated significantly with clinical severity of the disease and with the presence of histological features that imply chronic viral infection (periportal inflammation, cirrhosis), despite the fact that the supplementary assay for antibody to hepatitis C virus, using recombinant immunoblot assay, reduced the positive rate by 79%.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistence of hepatitis B viral DNA after serological recovery from hepatitis B virus infection

Chronic hepatitis B virus infection is a major medical problem worldwide. Apart from HBsAg carriers, hepatitis B virus has also been identified in some HBsAg-individuals with or without antibodies to viral antigens. The molecular mechanisms underlying hepatitis B virus persistence in HBsAg-individuals are unresolved, however. To identify a possible genetic basis for viral persistence, we cloned the viral genome from the liver of a patient serologically immune to hepatitis B virus infection. DNA sequence analysis of the complete viral genome identified numerous mutations in all viral genes. Analysis of the biological effects of these mutations revealed three major findings: a low level of HBsAg synthesis, absence of HBeAg production and a defect terminating viral replication. These data suggest that mutations accumulating during the natural course of hepatitis B virus infection may be a mechanism underlying viral persistence in HBsAg-individuals, presumably through escape from immune surveillance.

Incidence, determinants and significance of delayed clearance of serum HBsAg in chronic hepatitis B virus infection: a prospective study

To investigate the incidence, determinants and significance of delayed clearance of serum HBsAg in chronic hepatitis B virus infection, a prospective follow-up study was conducted in two consecutive groups of patients. Group I consisted of 984 patients (859 men and 125 women) with biopsy-proven chronic type B hepatitis, whereas group II consisted of 1,598 asymptomatic chronic carriers (998 men and 600 women) with normal serum aminotransferase activity. During a mean follow-up period of 4.0 +/- 2.3 yr, 19 patients (1.9%) of group I cleared HBsAg from their serum, whereas 35 patients (2.2%) in group II did so in a mean follow-up period of 2.7 +/- 1.4 yr. The annual incidence of delayed serum HBsAg clearance was 0.5% in group I and 0.8% in group II (p less than 0.02). The cumulative probability of HBsAg clearance was also higher in group II than in group I (p less than 0.007). Antibodies to HBsAg developed in 9 patients (47.4%) with chronic hepatitis and in 11 (31.4%) asymptomatic carriers who cleared serum HBsAg. Those who were HBeAg negative and those older than 40 at entry and those who exhibited cirrhosis during follow-up had a higher incidence of delayed HBsAg clearance. Gender, initial histological changes and hepatitis delta virus infection did not influence the occurrence of HBsAg clearance. Serum HBV DNA was not detectable by slot-blot hybridization but was still detectable by polymerase chain reaction in serum specimens collected within 1 yr of HBsAg clearance. Liver biopsy performed later in 10 patients showed no significant hepatitis activity or tissue HBV DNA, HBsAg or HBcAg.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum hepatitis B virus DNA in healthy HBsAg-negative Chinese adults evaluated by polymerase chain reaction

Serum hepatitis B virus (HBV) DNA was assayed using polymerase chain reaction, in 107 HBsAg-negative normal Chinese subjects. The results showed that eight subjects (7.5%) had HBV DNA. In the subgroup with antibody to hepatitis B surface antigen (anti-HBs) and to hepatitis B core antigen (anti-HBc), 7.3% (5/68) were positive for HBV DNA; HBV DNA was not detected in six individuals with anti-HBs only and in nine with anti-HBc only. In four persons with anti-HBc and anti-HBe, one had HBV DNA. In 20 subjects negative for all hepatitis B serological markers, two (10%) were found to have HBV DNA. This study indicates that serological markers are not adequate to rule out HBV infection, and it further implies that present blood donor screening methods may need improving.

Evidence against a requisite role for defective virus in the establishment of persistent hepadnavirus infections

The factors involved in the establishment of persistent hepadnavirus infection are poorly understood. Recent findings demonstrate that the sequence of the genome of hepatitis B virus (HBV) is variable in infected individuals and that, in some cases, virus mutants predominate. Our objectives in the present study were to analyze the variability of woodchuck hepatitis virus (WHV) genomes in an infected animal and to determine whether sequence heterogeneity played a critical role in the ability of WHV to induce chronic infection. We cloned and determined the complete nucleotide sequence of three supercoiled genomes from an animal that became infected after inoculation with a standardized WHV serum pool (i.e., the WHV7 virus pool). We found that there were four nucleotide substitutions among the three genome sequences as well as a 73-nucleotide deletion in one of the recombinants. DNA transfection experiments revealed that only one of the three recombinants was capable of independent replication. These data suggest that a significant proportion of replicative templates in woodchucks that are infected with WHV are defective virus genomes. Next, we compared the outcome of acute infection after inoculation with a serum pool containing a uniform population of replication competent virus (i.e., the WHV7R pool) with a serum pool composed of WHV genomes of variable sequence. The WHV7R serum pool originated from a woodchuck that became a chronic carrier after in vivo transfection of the liver with the infectious WHV7 recombinant. Neonatal woodchucks were inoculated with 5 x 10(6) WHV genome equivalents of either the WHV7 pool or the WHV7R pool. All animals in the study became acutely infected with WHV. Of the animals infected with the WHV7 serum pool, 65% became chronic carriers, while 80% of the animals infected with the WHV7R serum pool developed chronic infection. Thus, infection of woodchucks with a serum pool containing defective virus resulted in a rate of chronic WHV infection that was similar to, or even lower than, a rate from a pool containing only wild-type virus. This suggests that the presence of defective virus in the inoculum is not a prerequisite for the establishment of persistent hepadnavirus infections.

Identification and characterization of intrahepatic hepatitis B virus DNA in HBsAg-seronegative patients with chronic liver disease and hepatocellular carcinoma in Taiwan

To clarify the role of hepatitis B virus infection in HBsAg-seronegative patients with chronic liver disease and hepatocellular carcinoma in Taiwan, we examined the hepatitis B virus DNA in liver biopsy tissues of 112 patients by Southern blot analysis. The patients studied included 43 patients with nonalcoholic chronic liver disease, 21 patients with hepatocellular carcinoma and 48 control patients with other hepatobiliary and gastrointestinal diseases. To confirm the specificity of the intrahepatic hepatitis B virus DNA signal and to understand the structure of the integrated viral sequences, molecular cloning and DNA sequencing of an integrated hepatitis B virus DNA were done in one patient. Among 13 patients without serological evidence of previous hepatitis B virus infection, no hepatitis B virus sequences were found in the liver. In other HBsAg-negative patients with evidence of previous hepatitis B virus exposure, a substantial positive rate of intrahepatic hepatitis B virus DNA was found (7%). The intrahepatic hepatitis B virus DNA was all in integrated form. The positive rate among patients with nonalcoholic chronic hepatitis and cirrhosis (2%) was not different from that of the control group with other hepatobiliary and gastrointestinal diseases (4%). However, the positive rate of integrated hepatitis B virus DNA between hepatocellular carcinoma patients and nonhepatocellular carcinoma patients was statistically significant (19% vs. 3%, p less than 0.05). Molecular cloning and sequencing of a 3.0 kb EcoRI fragment of an integrated hepatitis B virus DNA from an anti-HBs-positive patient revealed that it was a partial copy of the hepatitis B virus genome.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B virus DNA detection and comparison with hepatitis B surface antigen

Hepatitis B surface antigen (HBsAg) has been used for the detection of hepatitis B virus (HBV). Recently, HBV detection using the polymerase chain reaction (PCR) has been shown to be a direct measure of complete virions and to be potentially a very sensitive method. Therefore, we attempted to analyze the relationship between HBsAg detection and HBV DNA assay by PCR. We tested HBV DNA by a modification of the PCR technique in serial sera from five chimpanzees experimentally infected with HBV and 29 human sera. Our new method of PCR analysis is as sensitive as former methods but is more simple and rapid than existing procedures. In chimpanzee studies, HBV DNA was detected 2-3 weeks before the appearance of HBsAg, and continued to be detectable 2 weeks after the production of antibody to HBsAg. Also, 3 of 11 chronic hepatitis B patients who lost HBsAg were positive for HBV DNA in serum, while all of patients who recovered from acute viral infection were negative for HBV DNA in serum. These results indicate that HBV DNA detection by PCR analysis is the most sensitive method currently available to detect the presence of complete virions in serum.

Characterization and biological properties of a hepatitis B virus isolated from a patient without hepatitis B virus serologic markers

We have developed a rapid method to characterize genomic diversity of low-level hepatitis B and related viral agents after their identification in serum by high-affinity HBsAg-antibody monoclonal antibody capture and subsequent polymerase chain reaction amplification. Serum from an individual with chronic liver disease and without hepatitis B virus serological markers but reactive by monoclonal antibody capture/polymerase chain reaction amplification was inoculated into a chimpanzee. After inoculation, an acute hepatitis B virus-like hepatitis developed in the chimpanzee. Analysis of serial liver biopsy samples showed the persistence of hepatitis B virus DNA for more than 17 mo after resolution of acute hepatitis and seroconversion. Applying the technique of restriction enzyme fragment analysis to serial chimpanzee liver biopsy samples and acute-phase sera, along with the serum inoculum, we established that all hepatitis B virus DNA sequences are derived from the same viral agent. We present evidence that the viral DNA persisted as a nonreplicating episomal form in the nucleus of hepatocytes. This study demonstrates that after clinical and serological recovery from an acute hepatitis, there may be persistence of low-level hepatitis B virus-related genome in the liver despite the presence of antibodies to HBsAg. Such persistence of viral genome may be a natural sequela of infection and may serve as a source of viral latency and possible reactivation. Finally, cloning and complete nucleic-acid sequencing of this virus have demonstrated multiple nucleotide and amino acid changes compared with all known hepatitis B virus subtypes. These changes may have contributed in part to a different antigenic composition or immunological reactivity of the host to this hepatitis B virus isolate.

Polymerase chain reaction to detect hepatitis B virus DNA and RNA sequences in primary liver cancers from patients negative for hepatitis B surface antigen

BACKGROUND AND METHODS

The role of hepatitis B virus (HBV) in the course of patients with primary liver cancer who are negative for hepatitis B surface antigen has been debated. We used the polymerase chain reaction to evaluate 28 such patients for the presence of DNA and RNA sequences of the virus; 22 of these patients had associated cirrhosis. The patients were from areas with different prevalences of HBV infection (South Africa, Italy, France, and Japan).

RESULTS

Antibodies to the surface and core antigens of HBV were detected in 10 of the 23 patients tested. HBV DNA sequences were detected in 17 of the 28 patients, including 8 of the 10 with HBV antibodies and 6 of 13 without HBV serologic markers. HBV RNA molecules were found in four of five tumors tested.

CONCLUSIONS

Our investigation indicates that transcriptionally active HBV genomes are present in various geographic areas among patients with liver cancer who are negative for hepatitis B surface antigen. This observation is consistent with an etiologic role for the virus in the development of these tumors.

Frequency of hepatic HBV-DNA in patients with cirrhosis and hepatocellular carcinoma: relation to serum HBV markers

As part of a larger study designed to investigate the interaction of factors such as cirrhosis and hepatitis B virus infection as aetiological agents in the development of hepatocellular carcinoma, we investigated the status of hepatic HBV-DNA sequences in 156 cirrhotic patients. Forty-one were HBsAg seropositive and 18 (44%) of these had HBV-DNA sequences detectable in their livers. There are also 26 subjects who showed markers of a previous HBV infection (anti-HBs/anti-HBc), only one (4%) of whom had demonstrable hepatic HBV-DNA sequences. No sequences were found in any of the remaining 89 patients who were seronegative for all markers. Thus, liver HBV-DNA was only detected in the presence of a serum marker, usually HBsAg.

Detection of integrated hepatitis B virus DNA in hepatocellular carcinoma cell lines by nonradioactive in situ hybridization

A sensitive and specific nonradioactive in situ hybridization method capable of detecting single-copy integrated hepatitis B virus (HBV) DNA sequences in hepatocellular carcinoma (HCC) cell lines was developed. In situ hybridization of biotinylated HBV (adr, adw) DNA probes with nine different human HCC cell lines were carried out in 96-well microtiter plates. Integration was detected in HCC cell lines HCCM, Hep3B, huH-1, huH-4, and PLC/PRF/5. Detection of single-copy HBV DNA sequences was also achieved in Hep3B and huH-4. HCC cell lines HepG2, HUH-6, HUH-7, Mahlavu, and the non-HCC control MCF-7, gave clear negative results. These results show a 100% correlation with those obtained by Southern blot hybridization assay. The results demonstrate that nonradioactive detection of single-copy integrated HBV DNA sequences in HCC cell lines is possible by the method described, which has potential application for viral genome analysis requiring in situ hybridization.

Persistence of hepatitis B virus DNA after serological clearance of hepatitis B virus

Using Southern blot technique, the state of hepatitis B virus (HBV) DNA in liver tissue was investigated in 16 patients who were sero-negative for hepatitis B surface antigen (HBsAg) but positive for its antibody (anti-HBs). In only one case, was HBV DNA found in liver tissue in a heterogeneously integrated form. In this case, digestion with Taq I demonstrated integrated HBV DNA as two definite bands at 1.8 and 0.5 kbp. This suggests that HBV DNA in some cases persists even after HBV infection has been cleared serologically. It is possible that this persistence of HBV DNA plays an important role in hepatocarcinogenesis.

Detection of hepatitis B virus DNA using the polymerase chain reaction technique

The polymerase chain reaction (PCR) technique has been utilized for the detection of hepatitis B virus (HBV) DNA, and several factors related to the selection of primer pairs for the PCR amplification have been demonstrated. The sensitivity of the PCR assay was compared with that of slot-blot hybridization for detecting HBV-DNA. Analysis by the PCR technique with Southern blot hybridization provided a greater than 10(4)-fold increase in sensitivity over the slot-blot hybridization analysis. Also, a rapid and sensitive PCR method for the detection of serum HBV-DNA was developed: HBV-DNA is released from virions by incubating serum with NaOH followed by neutralization with HCl. HBV-DNA sequences are then detected by agarose gel electrophoresis and ethidium bromide staining after PCR amplification with successive sets of primer pairs. In testing serial samples from chimpanzees experimentally infected with HBV, HBV-DNA was detected 2-3 wk before the appearance of hepatitis surface antigen (HBsAg) and continued to be detectable for a short period after the production of antibody to HBsAg. Results from testing of human serum demonstrated that the majority of patients with HBsAg in serum had HBV-DNA as well and that some patients had HBV-DNA in serum in the absence of HBsAg.

Comparison of serum hepatitis B virus replication markers in patients with chronic hepatitis B: studies on HBeAg/anti-HBe system, viral DNA polymerase and HBV-DNA

The detection of HBV-DNA in serum by molecular hybridization is the most sensitive and specific marker or replication and infectivity of hepatitis B virus and currently is proposed as a routine diagnostic technique in the follow-up of HBV-related diseases. Comparing different techniques already described, we found that direct spotting of serum samples on nitrocellulose membranes under vacuum filtration, followed by denaturing and neutralizing washes is more practical, simple, sensible and reproducible. DNA polymerase assay using phosphonoformic acid as specific viral inhibitor has shown 86.8% of concordance with HBV-DNA detection, and so, it is an useful alternative in the follow-up of hepatitis B chronic patients. We found 19.2% HBeAg positive samples with no other markers of viral replication and no anti-HBe positive sample had detectable HBV-DNA. Discordance between the 2 systems have been extensively described, and we confirm this for the first time in our country. Molecular biological techniques are essential to determine the replication status of chronic hepatitis B patients.

In vitro amplification of hepatitis B virus sequences from liver tumour DNA and from paraffin wax embedded tissues using the polymerase chain reaction

A 185 base pair fragment from the core-polymerase overlap region of the hepatitis B virus (HBV) genome was amplified using the polymerase chain reaction (PCR). The results were compared with those of Southern blotting on extracted DNA from eight hepatocellular carcinomata. The data agreed with those of Southern blotting in six cases (two positive, four negative) but in two other positive cases PCR failed to amplify HBV sequences. This suggests deletion or mutation, or both, of this viral region in these cases. PCR was also used to amplify HBV sequences from formalin fixed, paraffin wax embedded tissue. Tissue inhibition of PCR occurred which increased with the number of tissue sections. It was present in tissues from different organs and species and fixed by different procedures, thus highlighting the need for a positive control during amplification. Use of formalin fixed Alexander cells, however, showed a sensitivity of one viral copy per 5000 cells. Confirmation of the identity of the PCR products was carried out using PCR-generated biotinylated probes, and suggested the insertion of extra nucleotide sequences or infection with an HBV variant in one case.

Hepatocellular carcinoma with normal adjacent liver. Hepatitis B virus DNA status

We investigated hepatitis B virus (HBV) DNA status in the liver of 22 patients with hepatocellular carcinoma (HCC) developed on a non-cirrhotic, histologically normal liver tissue. HBV serological markers were present in 2 of the 22 subjects. HBV DNA sequences were identified in the liver of only 5 of the 22 patients with HCC. Evidence for clonal expansion of HBV-infected cells was found for one HBsAg-positive subject. This study indicates a much lower rate of HBV DNA positivity in the group of HCC developed on histologically normal livers as compared to that observed in HCC with liver cirrhosis.

Non-A, non-B hepatitis

Diagnosis of non-A, non-B hepatitis (NANB) is made after exclusion of other known causes of hepatitis. Parenterally spread non-a, non-B hepatitis (PNANB) and enterally transmitted non-A, non-B hepatitis (ENANB) almost certainly appear to be two different diseases. The definite causative agents have not hitherto been identified. Much of our knowledge of NANB is based on (i) experimental studies on chimpanzees; and (ii) epidemiological studies. Parenterally spread non-A non-B hepatitis caused by whole blood transfusion and blood-product infusion has different incubation periods and may be caused by different agents. It is a mild disease clinically, and the majority of the patients are asymptomatic. It can be prevented only by judicious use of blood transfusion. Whenever possible, blood/blood products should be derived from individual volunteer donors who are anti-HBc sero-negative and have serum alanine transaminase of under 45 IU/l. Enterally-transmitted non-A non-B hepatitis is endemic in the Indian subcontinent, South-East Asia, North and East Africa and Latin America. Epidemic NANB is usually transmitted by water supply contaminated with feces. ENANB has a predilection for young adults. The disease is usually mild, except in pregnant women, who have a high case-fatality rate from fulminant hepatic failure. Control measures include provision of clean water supplies, safe disposal of human excreta and sound personal and food hygiene practices.

Status of hepatitis B virus DNA in alcoholic liver disease: a study of a large urban population in the United States

Two reports have shown hepatitis B virus DNA in serum and liver tissue in alcoholic liver disease with negative serum HBsAg, suggesting a pathogenetic role for hepatitis B virus. We studied hepatitis B virus DNA in serum and liver from three groups of alcoholic patients; (Group 1) 50 patients without liver disease, (Group 2) 108 patients with alcoholic liver disease and (Group 3) five patients with alcoholic liver disease and hepatocellular carcinoma. Serum was tested for HBsAg, anti-hepatitis B core and anti-hepatitis B surface by radioimmunoassay and hepatitis B virus DNA by direct spot hybridization. Liver tissue from Groups 2 and 3 (113 patients) was examined by Southern blot analysis using 32P-labeled hepatitis B virus DNA clone from pBR322. Controls were 21 patients with chronic hepatitis B virus (14 patients with chronic active hepatitis, seven patients with cirrhosis and hepatocellular carcinoma). Serum and tissue were analyzed for hepatitis B virus DNA. Hepatitis B virus DNA was not detected in either serum or liver tissue in any of the 163 patients (Groups 1 to 3). In contrast, among the controls, hepatitis B virus DNA was present in the serum of 15 of the 21. Tissue DNA in those with chronic active hepatitis revealed 10/14 with free hepatitis B virus DNA, two with integrated sequences and two with no viral sequences. All seven patients with hepatocellular carcinoma had integrated viral DNA sequences in the tumor tissues. From these results, it appears that hepatitis B virus does not play a role in the pathogenesis of alcoholic liver disease.

Latent hepatitis B virus infection with full-length viral genome in a patient serologically immune to hepatitis B virus infection

The presence, state, physical structure and cellular localization of hepatitis B virus (HBV) DNA were investigated in a patient with hepatitis B surface antigen (HBsAg)-negative chronic liver disease. HBV serology was positive for antibodies to hepatitis B core antigen (anti-HBc), to hepatitis B e antigen (anti-HBe) and to HBsAg (anti-HBs); no HBV DNA was detectable in serum. Southern blot analyses of DNA extracted from the liver demonstrated free monomeric HBV DNA as two distinct species: a predominant species of fully double-stranded relaxed circular molecules and a minor species of linear molecules of 3.2 kilobase pairs (kbp) length. Restriction enzyme analyses identified the HBV genome as HBsAg subtype adw2. Cell fractionation studies further revealed that the free viral DNA species were localized exclusively in liver cell nuclei. These findings in a patient serologically immune to HBV infection demonstrate that in hepatocytes HBV can establish a latent infection, characterized by the extrachromosomal presence of a full-length viral genome without production of infectious virus or synthesis of viral antigens.

Hepatitis B virus and hepatitis B-related viral infection in renal transplant recipients. A prospective study of 90 patients

Hepatitis B virus (HBV) infection may induce severe hepatitis and affect long-term survival of kidney transplant recipients. Persistent viral infection has been shown to occur despite the absence of usual serologic markers. The liver and serum HBV deoxyribonucleic acid (DNA) status of 90 patients were studied prospectively; recently transplanted patients, both hepatitis B virus surface antigen (HBsAg)-positive and negative, with and without liver disease, were investigated with HBV serology, serum HBV DNA, and liver histology. Thirty-four patients had detectable HBsAg, and 21 had viral multiplication at the time of transplantation. Serial HBV DNA determinations performed in 57 of 90 patients disclosed (a) reactivation of HBV replication in 11 of 12 HBsAg-positive patients, (b) increase of viral replication when positive on the initial sample in 6 of 11 patients, and (c) development of HBV replication in 7 of 35 of the HBsAg-negative patients. Moreover, liver HBV DNA studies showed a statistical correlation between the presence of integrated liver HBV DNA and chronic hepatitis in HBsAg-negative patients. This study demonstrates prospectively the significant association of HBsAg-positive as well as HBsAg-negative HBV infection with chronic hepatitis and suggests that immunosuppressive therapy may enhance the viral replication in both HBsAg-positive and negative subjects.

HBV-DNA sequences are rarely detected in the liver of patients with HBsAg-negative chronic active liver disease and with hepatocellular carcinoma in Italy

Hepatitis B virus sequences were studied by molecular hybridization in liver biopsies from patients with HBsAg-negative chronic liver disease or hepatocellular carcinoma, collected in Italy. Among the 42 patients with chronic liver disease who had no history of drug addiction, alcohol abuse nor evidence of metabolic and autoimmune disorders, only two (5%) had HBV-DNA sequences in the liver, although 23 of them (57%) were positive for antibodies to HBV in serum. HBV-DNA was also demonstrated in integrated form in the tumorous tissue of one out of eight cases with HBsAg-negative hepatocellular carcinoma. These incidences of HBV-DNA positivity in the liver are lower than those reported from other Mediterranean areas and similar to those of North Europe, United States and Japan, suggesting that etiologic factors other than HBV are responsible for the majority of HBsAg-negative chronic liver diseases in our region.

Spot-blot hybridization assay for the detection of hepatitis B virus DNA in serum: factors determining its sensitivity and specificity

Factors determining the sensitivity and specificity of the spot-blot hybridization technique for the detection of hepatitis B virus DNA in serum were systematically investigated. Methods for pretreatment of serum samples, mode of application of the samples to the transfer membranes, blot treatment and hybridization conditions were all found to affect the sensitivity of the assay. The optimum hybridization procedure was found to be incubation of serum samples with salt, NaOH, formaldehyde and detergent, followed by spot application of the samples. This method specifically detected hepatitis B virus DNA in serum with a sensitivity 5 to 15 times higher than the presently used assay procedures.

Lack of hepatitis B virus DNA sequences in sera from patients with acute and chronic liver diseases diagnosed as non-A, non-B-hepatitis

The sera of 15 individuals with transfusion-associated acute or chronic non A, non B hepatitis, which lacked hepatitis B virus markers, were tested for hepatitis B virus DNA by dot blot hybridization test. Three sera of two patients positive in this test, however, also gave positive results when the labeled plasmid was used as probe instead of labeled HBV-DNA, indicating false positive results in the initial test. In conclusion, the data indicated that sera of patients with confirmed non A, non B hepatitis do not contain DNA-sequences in the serum hybridizing with HBV-DNA.

Hepatitis B virus RNA transcripts and DNA in chronic liver disease

To study the relation between gene expression of hepatitis B virus (HBV) and liver disease, we studied HBV RNA transcripts and DNA in liver-biopsy specimens from 30 patients with chronic liver disease (17 seropositive for hepatitis B surface antigen and 13 seronegative). HBV-specific RNA was found in all the seropositive patients and in none of the seronegative patients. Two major RNAs, sizes 29S (long) and 21S (short), were found in nine seropositive patients, of whom seven had free HBV DNA and eight were seropositive for hepatitis B e antigen. Six of the nine patients had hepatitis B core antigen in hepatocytes and active liver disease. In contrast, inactive liver disease was noted in the remaining eight seropositive patients, who had only one (21S) RNA. None of these patients had free HBV DNA (five of eight had integrated DNA) or hepatitis B core antigen in hepatocytes. Hybridization analysis suggested that 29S and 21S RNAs are messenger RNAs of hepatitis B core antigen and hepatitis B surface antigen, respectively. These data indicate that the free DNA and its products are causally related to the activity of liver disease and that once HBV DNA has been integrated, the disease will become quiescent. None of the determinants were identified in patients seronegative for hepatitis B surface antigen.

Correlation of HBV DNA and monoclonal reactivity to HBsAg in serum of patients with HBV infection

Hepatitis B virus (HBV) DNA hybridization assay, a monoclonal radioimmunoassay (M-RIA) for hepatitis B surface antigen (HBsAg) and conventional polyclonal immunoassays for HBV associated antigens were used to study sera from patients on dialysis and with acute hepatitis B. HBV DNA was detectable in hepatitis B e antigen (HBeAg) negative patients with acute hepatitis but not in HBsAg+ HBeAg- dialysis patients. In acute hepatitis, HBsAg immunoreactivity by M-RIA could still be detected even though a commercial immunoassay for HBsAg, the AUSRIA II, and the HBV DNA assay were no longer positive. Unlike in acute HBV infection, serum HBV DNA was detectable in dialysis patients who were AUSTRIA II negative but M-RIA positive. Serial determination of HBsAg by M-RIA and HBV DNA revealed episodes of HBV DNA positivity months after both the HBsAg was no longer positive by polyclonal immunoassay. Thus, the M-RIA for HBsAg and the molecular hybridization technique for HBV DNA are sensitive and specific assays for the identification of potentially infectious individuals who would not have been characterized as such based on the results of conventional polyclonal immunoassays.

HBsAg clearance in chronic active hepatitis B. A possible cause of cryptogenic cirrhosis

Three patients with chronic hepatitis B infection, two with chronic active hepatitis and cirrhosis, and the third with quiescent cirrhosis, cleared HBsAg from their serum and eventually developed anti-HBs. All three were asymptomatic and had nearly normal serum aminotransferases following loss of HBsAg. Liver biopsy revealed cirrhosis in each patient. With the development of anti-HBs, these patients became serologically indistinguishable from patients with a cryptogenic cirrhosis who had prior unrelated exposure to hepatitis B. Remote chronic hepatitis B infection may be a more common cause of cryptogenic cirrhosis than is commonly appreciated.

Hepatitis B virus infection and liver disease in Ethiopian immigrants to Israel

We assessed infection with hepatitis B virus in 357 Ethiopians who immigrated to Israel. Hepatitis B virus infection, as measured by the presence in the serum of HBsAg, anti-HBs, or anti-HBc, started at an early age (35% at the age of 1 to 4 years) and reached an overall rate of 98% in individuals over 40 years old. A high rate of HBsAg antigenemia in the young age group (19% at the age of 1 to 8 years) was associated with HBeAg and serum hepatitis B virus DNA. However, hepatitis B virus DNA was rarely detected in HBsAg-positive serum of older individuals who were anti-HBe-positive. No hepatitis B virus DNA sequences were detected in the serum of individuals who had anti-HBs. Despite the extremely high rate of hepatitis B virus infection that occurred at an early age, no clinical evidence of chronic liver disease in this population was detected.

Clonal analysis of intrahepatic T lymphocytes in chronic active hepatitis. Isolation of a T-cell line specific for hepatitis B core antigen from a patient with serological evidence of exposure to HBV

We have evaluated whether peripheral blood and hepatic lymphocytes from a patient with chronic active hepatitis (CAH) and antibodies to HBV in serum were specifically sensitized to HBV envelope antigens (HBsAg and pre-S Ag) or to HBcAg. No proliferation to HBV antigens was demonstrated upon stimulation of peripheral blood mononuclear cells either unfractionated or enriched in CD4+ (helper/inducer) T cells. Of 15 T-cell cloned lines (7 CD8+ and 8 CD4+) obtained by limiting dilution in the presence of PHA and recombinant IL2 from liver-infiltrating lymphocytes, one, designated H2, showed specific sensitization to HBcAg, whereas none demonstrated sensitization to viral envelope antigens. The H2 line displayed the CD8+ phenotype, suppressor activity on polyclonal immunoglobulin production and IL2-dependent, HBcAg-specific proliferation. These results suggest that in patients with CAH and serological evidence of previous exposure to HBV, it is possible to obtain lymphocytes specifically sensitized to HBcAg from liver biopsy.

Hepatitis B virus DNA in the hepatocyte. A series of 160 biopsies

DNA-DNA hybridisation was used to examine 160 liver biopsies for the presence of the hepatitis B virus genome. HBeAg-positive HBsAg carriers were found to have replicating viral DNA in the hepatocytes and, very occasionally, HBV DNA was also integrated into the chromosomes. A high proportion of the anti-HBe-positive HBsAg carriers also have replicating HBV DNA and in the remainder integrated sequences are often, but not always, seen. No evidence was found, however, to implicate HBV in HBsAg-negative patients with alcoholic liver disease, nor in patients with a variety of other liver diseases including non-A, non-B hepatitis.