Influence of hepatitis delta virus superinfection on the clearance of hepatitis B virus (HBV) markers in HBV carriers in Japan

Spontaneous loss of surface antigen among adults living with chronic hepatitis B virus infection: a systematic review and pooled meta-analyses

BACKGROUND

Spontaneous loss of HBsAg (known as functional cure) in patients with chronic hepatitis B virus (HBV) infection significantly reduces liver-related complications. HBsAg loss has been suggested to be higher in non-endemic regions than in endemic regions in individual studies. We systematically determined a pooled annual rate of HBsAg loss in adults with untreated chronic HBV infection and examined the effect of regional endemicity.

METHODS

In this systematic review and meta-analysis, we searched PubMed and Embase for observational cohort studies and non-treatment arms of randomised controlled trials reporting proportions of patients with chronic HBV infection that achieved spontaneous HBsAg loss, published up to Oct 1, 2018. We excluded randomised controlled trials from meta-analyses because of substantial cohort differences. Two reviewers (KZ and CC) independently extracted data from accepted full-text studies, with discrepancies discussed with a third reviewer (NT). We assessed rate of HBsAg loss, and stratified results by whether the underlying cohort arose primarily from an endemic region (defined as having prevalence of chronic HBV greater than 2%) or non-endemic region. This study is registered with PROSPERO, number CRD42018074086.

FINDINGS

Of 5186 studies screened, 67 (11 randomised controlled trials, 39 prospective and 17 retrospective cohort studies) met the inclusion criteria and 56 were included in meta-analyses after exclusion of randomised controlled trials. Spontaneous HBsAg loss occurred in 3837 (7·8%) of 48 972 patients, with cumulative 352 381 person-years of follow-up. The pooled annual incidence of HBsAg loss was 1·17% (95% CI 0·94-1·41, I²=97%). Rates did not differ by endemicity: 1·19% (0·88-1·54) in endemic versus 1·29% (0·99-1·62) in non-endemic cohorts.

INTERPRETATION

Globally, spontaneous HBsAg loss occurs infrequently (about 1% per year) in treatment-naive adults with chronic HBV infection. The low and homogeneous rate of HBsAg loss highlights the need for new therapeutics aimed at achieving functional cure across different patient groups and geographical regions.

FUNDING

NIH National Institute of Diabetes and Digestive and Kidney Diseases.

Lamivudine therapy in chronic delta hepatitis: a multicentre randomized-controlled pilot study

BACKGROUND

Delta virus (HDV)-related chronic hepatitis is difficult to treat.

AIMS

To evaluate the efficacy of lamivudine 100 mg daily on serum HDV-RNA, hepatitis D virus antibodies and alanine aminotransferase levels, liver histology, and on hepatitis B surface antigen seroconversion.

METHODS

Thirty-one hepatitis B surface antigen-positive, HDV-RNA-positive patients with ALT > or = 1.5 upper normal level and compensated liver disease were randomized (1:2 ratio) to placebo (group A, n = 11) or lamivudine (group B, n = 20) for 52 weeks; thereafter, all patients were given lamivudine for 52 weeks and followed up for 16 weeks.

RESULTS

Twenty-five patients (81%) completed the study. No patient was HDV-RNA-negative at week 52; three patients (11%) were negative at week 104. Two of them remained HDV-RNA-negative at week 120, and one lost the hepatitis B surface antigen without seroconversion. Paired pre-treatment and week 104 liver biopsies were available from 19 patients: of which three of seven (43%) from group A and two of 12 patients (17%) from group B had a > or =2 point decrease in the Ishak necroinflammatory score.

CONCLUSION

A sustained complete response was achieved in 8% of hepatitis D virus-infected patients treated with lamivudine and a partial histological response in 26% of them. Hepatitis D virus viraemia was unaffected, even in patients when hepatitis B virus replication was lowered by lamivudine therapy.

Clearance of hepatitis B surface antigen in chronic carriers of hepatitis delta antibodies

BACKGROUND/AIMS

We evaluated the rate of seroclearance of the hepatitis B surface antigen (HBsAg) and its clinical significance in patients with chronic hepatitis delta virus (HDV).

METHODS

Antibody to HDV was tested in HBsAg-positive subjects admitted to our Hospital from 1991 to 1995. In 1997, a biochemical and virologic study was performed in the surviving anti-HD-positive patients who had not undergone transplantation. As a control, a cohort of 106 HBsAg-positive, anti-HD-negative patients was studied.

RESULTS

One hundred and forty-one subjects were originally positive for anti-HD. After 4 years of follow-up, six of the 60 patients who underwent re-evaluation (10%) had cleared the HBsAg: three of the six patients had minimal changes at the initial liver histology and normal ALT, whereas in the remaining three patients with chronic active hepatitis ALT normalized during the observation. Anti-HD persisted in five of the six patients. Only one patient had raised anti-HBs. In contrast, three of 106 HBsAg carriers without HDV infection (2.8%) cleared the HBsAg within the same time and seroconverted to anti-HBs (p=0.002).

CONCLUSION

HBsAg clearance is increased over the years in HDV patients compared to ordinary HBsAg carriers, and is often associated with improvement of HDV disease without seroconversion to anti-HBs.

Displacement of hepatitis B virus by hepatitis C virus as the cause of continuing chronic hepatitis

BACKGROUND/AIMS

It has been shown that hepatitis C virus (HCV) superinfection may suppress hepatitis B virus (HBV) leading to hepatitis B surface antigen (HBsAg) clearance and that hepatitis may persist after HBsAg clearance in a few patients. The role of HCV in continuing hepatitis after termination of chronic HBsAg antigenemia remains to be explored in a series of patients.

METHODS

HCV markers were studied using second generation enzyme immunoassay and polymerase chain reaction with reverse transcription and were compared between 41 patients with persistent alanine aminotransferase (ALT) elevation (hepatitis group) and 82 age/sex-matched patients with normal ALT (control group) after HBsAg clearance.

RESULTS

Twenty-six (63%) of the 41 hepatitis group patients were seropositive for antibodies to HCV (anti-HCV) compared with only 4 (5%) of 82 controls (P < 0.0001). Six patients of the hepatitis group and 1 control had an episode of acute hepatitis C with seroconversion of anti-HCV 1-68 months before HBsAg clearance. Of those seropositive for anti-HCV, serum HBV DNA was not detectable, and serum HCV RNA was detected in 23 (88.5%) of the 26 hepatitis patients but none of the 4 controls (P < 0.001). Liver biopsy in 6 anti-HCV positive patients with continuing hepatitis showed features compatible with chronic hepatitis C. HCV RNA, but not HBV DNA, was detected in liver tissues of these 6 patients.

CONCLUSIONS

The results suggest that HCV may usurp the role of HBV in chronic hepatitis and act as the major cause of continuing hepatitis or ALT elevation after HBV/HBsAg clearance.

Risk of liver cirrhosis and hepatocellular carcinoma in subjects with hepatitis B and delta virus infection: a study from Kure, Japan

To investigate the effect of hepatitis delta virus (HDV) superinfection on the long-term outcome of Japanese subjects with chronic hepatitis B virus (HBV) infection, we examined the presence of antibodies to hepatitis delta antigen (anti-HD) in serial serum samples collected from 1127 subjects with chronic HBV infection. The subjects were followed for at least 36 months (mean: 121.3 months) between 1973 and 1991. Among 69 cases where anti-HD was detected, eight (12%) developed liver cirrhosis (LC) and six (9%) developed hepatocellular carcinoma (HCC). However, among 1058 cases without anti-HD, there were 43 patients (4%) who developed LC and 29 (3%) who developed HCC. The prevalence of LC and HCC was significantly higher among the cases with anti-HD than those without anti-HD. The proportion of LC and HCC per 1000 person years was 10.46 and 7.84, respectively among cases with anti-HD, and 4.05 and 2.73 among those without anti-HD, respectively. The overall relative risk of LC and HCC was 2.58 and 2.87, respectively; 95% confidence interval (CI): LC, 1.14-5.13; HCC, 1.03-6.23. These results indicate that in the Kure district in Japan, where HDV infection of persons infected with HBV is about 6%, such superinfection increases the risk of LC and HCC.

In vitro culture systems for hepatitis B and delta viruses

The development of tissue culture technology has led to invaluable information in many fields of modern virology. Until recently, the lack of an in vitro culture system for the hepatitis B virus (HBV) was a considerable impediment to the study of its life cycle at the cellular and molecular levels. However, it did not prevent its isolation and molecular cloning. Such has been the case also for the hepatitis delta virus (HDV), the genome of which was cloned and sequenced before its replication could be observed in cultured cells. In recent years, tissue culture systems for HBV and HDV have been developed progressively by the identification of permissive, established cell lines for production of virions and susceptible primary hepatocyte cultures for infection assays. I will briefly review here the recent experiments that have contributed to replicate HBV and HDV in cell culture systems.

Hepatitis type C virus infection in patients with type B chronic liver disease

Anti-c100-3 (Ortho) was determined in the sera of 152 patients with HBs antigen-positive chronic liver diseases to assess coinfection of hepatitis B virus (HBV) and hepatitis C virus (HCV). Eleven patients (7.2%) were positive for anti-c100-3. Anti-CP-9 (Okamoto) and HCV-RNA (RT-PCR) were also examined in these 11 patients. Anti-CP-9 was detected in 7 patients and HCV-RNA was detected in all 11 patients. Four of the 11 anti-c100-3-positive patients were positive for HBe antigen (HBeAg) and others were negative. In 8 of the 11 patients, HCV was suspected to be superinfected by blood transfusion. In HBeAg-positive patients, serum glutamic pyruvic transaminase (SGPT) was elevated in relation to active replication of HBV shown by DNA-polymerase activity. The histological findings showed chronic active hepatitis, with or without cirrhosis. On the other hand, in HBeAg-negative patients, SGPT fluctuated without evidence of active replication of HBV. Active inflammation in the liver was observed in 3 of 5 HBeAg-negative patients by liver biopsy. These findings suggest that HBV might play an important role in chronic active inflammation in HBeAg-positive patients coinfected with HCV, and that HCV might be responsible for continuous inflammation in HBeAg-negative patients coinfected with HCV.

A long-term follow-up of five patients with hepatitis delta virus in Japan

From 1973 to 1989 five patients with hepatitis delta virus having anti-hepatitis delta antibodies continuously in the serum for more than 5 years were identified among 1019 hepatitis B virus carriers who were being followed-up for more than 3 years (mean 8.9 years). Of the five patients with antibodies, three had a history of blood transfusion, in two cases the transfusion was massive, and one patient had been addicted to narcotics given intravenously 35 years before. In the remaining patient, the route of superinfection could not be determined. Hepatitis delta antigen was detected in hepatocyte nuclei of one of the three patients in whom liver biopsies were performed and there was chronic persistent hepatitis detected by an indirect immunoperoxidase technique. During the follow-up, hepatocellular carcinoma developed in one case but the clinical prognosis was favourable in the remaining four cases.

Decreased creatinine clearance which may be observed during prostaglandin E1 therapy: is it reversible with discontinuation of therapy?

A study was carried out in four patients with nephrotic diabetic nephropathy in order to determine if decreased creatinine clearance observed during prostaglandin E1 therapy was reversible on discontinuation of therapy. The patients received 40 micrograms prostaglandin E1 intravenously twice daily for 4 weeks and creatinine clearance and daily excretion of urinary protein were measured immediately before, during and 2 weeks after therapy. Total serum protein and serum albumin were also determined. There was a significant decrease in creatinine clearance during therapy and after therapy clearance increased but not significantly. It is concluded that decreased creatinine clearance during prostaglandin E1 therapy has a partial reversibility on discontinuation of the treatment.

Chronic delta hepatitis in haemophiliacs

The seroepidemiological profile of HBV and HDV was investigated in 640 male haemophiliacs. Twenty-seven of forty-four HBsAg carriers were anti-HDV-IgG positive, 22 were also anti-HDV-IgM positive. A markedly lower prevalence of HDV infection was found in patients with anti-HBc in the absence of HBsAg and anti-HBs (6/41). Repeated detection of anti-HDV-IgM in 5/41 individuals of this group indicates that circulating HBsAg is not an absolute prerequisite for chronic HDV infection. Overall, chronically active HDV infection was detected more frequently in quiescent than in active chronic HBV infections. Anti-HDV-IgM was not detected in the absence of anti-HDV-IgG antibodies. Anti-HDV-IgG may disappear after resolution of HDV infection, as indicated by the low prevalence (1/42) in such individuals with past HBV infection as well as by loss of anti-HDV-IgG observed in two patients.

Tissue culture system for infection with human hepatitis delta virus

An in vitro culture system was developed for assaying the infectivity of the human hepatitis delta virus (HDV). Hepatocytes were isolated from chimpanzee liver and grown in a serum-free medium. Cells were shown to be infectible by HDV and to remain susceptible to infection for at least 3 weeks in culture, as evidenced by the appearance of RNA species characteristic of HDV replication as early as 6 days postinfection. When repeated experiments were carried out on cells derived from an animal free of hepatitis B virus (HBV), HDV infection occurred in a consistent fashion but there was no indication of infection with the HBV that was present in the inoculum. Despite numerous attempts with different sources of HBV inocula free of HDV, there was no evidence that indicated susceptibility of these cells to HBV infection. This observation may indicate that HBV and HDV use different modes of entry into hepatocytes. When cells derived from an HBV-infected animal were exposed to HDV, synthesis and release of progeny HDV particles were obtained in addition to HBV replication and production of Dane particles. Although not infectible with HBV, primary cultures of chimpanzee hepatocytes are capable of supporting part of the life cycle of HBV and the entire life cycle of HDV.

Acute hepatitis C virus superinfection followed by spontaneous HBeAg seroconversion and HBsAg elimination

Acute hepatitis C virus superinfection followed by spontaneous hepatitis B e antigen seroconversion and hepatitis B surface antigen clearance in a patient with chronic type B hepatitis is described. The observations suggests that HCV may exert a suppressive effect on hepatitis B virus.

Why most patients with hepatitis delta virus infection are seronegative for hepatitis B e antigen. A prospective controlled study

A prospective age/sex matched control and follow-up study was conducted to explore the reason(s) for the association of hepatitis delta virus (HDV) infection with hepatitis B e antigen (HBeAg) negative hepatitis B surface antigen (HBsAg) carrier state. Over a 3-year period, a total of 110 patients (104 males and six females) with acute HDV superinfection were documented in our unit. Twenty-four (21.8%) of them were HBeAg positive at the onset of acute HDV infection. In the control study, 110 age- and sex-matched asymptomatic HBsAg carriers with normal serum transaminase, as well as 110 age- and sex-matched patients with chronic type B hepatitis were randomly selected from the computer files of the same 3-year period of entry. The prevalence of serum HBeAg in patients with HDV infection was similar to that of asymptomatic HBsAg carriers (20.9%), but significantly lower than that of the patients with chronic type B hepatitis (72.7%). In a follow-up study of 16 HBeAg-positive patients with HDV infection, eight (50%) cleared HBeAg and three (18.8%) seroconverted to anti-HBe within 3 months. The HBeAg clearance rate was significantly higher than for chronic type B hepatitis and asymptomatic carriers (p less than 0.01). The results suggest that the low prevalence of serum HBeAg in HDV infection simply reflects the HBeAg/anti-HBe status of the asymptomatic HBsAg carriers in the population under study. Also in some patients HDV superinfection may itself suppress HBV and thus clear HBeAg.

Hepatitis delta virus infection in different time periods in Japan

To investigate the prevalence of hepatitis delta virus (HDV) infection in different time periods between 1973 and 1988, antibody to hepatitis delta antigen (anti-HD) was tested for in sera collected from 1088 cases with acute or chronic hepatitis B virus (HBV) infection treated at Kure National Hospital. Between 1979 and 1983, anti-HD was first detected in 16% (four of 25 cases) of patients with acute hepatitis B, in 6.8% (11 of 161 cases) of asymptomatic HBV carriers and 26% (51 of 196 cases) of those with chronic liver disease. Except for this time period anti-HD was hardly detected. These findings indicate that sporadic HDV infections existed in this area between 1979 and 1983.

Hepatitis D virus infection among intravenous drug abusers in Taiwan: analysis of risk factors and liver function tests

To investigate the prevalence of hepatitis D virus (HDV) and hepatitis B virus (HBV) infection among intravenous drug abusers in Taiwan, a total of 761 male prisoners, including 680 intravenous drug abusers, were studied for serological markers of HBV and HDV. Questionnaires were distributed to evaluate the risk factors for HDV infection and also to estimate the strength of association among HDV infection and the risk factors. HBV infection was common, and the positive rates of HBV markers between intravenous drug abusers and non-drug abusers were not statistically different. However, the positive rate of the antibody to HDV was significantly higher among intravenous drug abusers than among non-drug abusers (21.3% vs. 8.6%). Of 131 chronic HBV carriers with intravenous drug abuse, 119 (91%) were anti-HD positive. Using multiple logistic regression models, we found that the most important risk factor for HDV infection was hepatitis B surface antigen (HBsAg) carriage, and intravenous drug addiction the next. A matched case-control study also was conducted to compare liver function tests among both anti-HD- and HBsAg-positive group anti-HD-negative, and HBs-AG-positive group as well as those with neither positive. Statistically significant difference in liver function tests was not found. It is concluded that the HBsAg carriers with intravenous drug abuse in Taiwan are commonly HDV infected with and that the infection does not seem to affect the liver as assessed by liver function tests.

Cloned hepatitis delta virus cDNA is infectious in the chimpanzee

A head-to-tail trimer of a full-length cDNA clone of the hepatitis delta virus (HDV) genome was examined for infectivity by direct inoculation into the liver of a chimpanzee that was already infected with hepatitis B virus. Five weeks after inoculation, a marked elevation of serum alanine aminotransferase activity was observed, followed by the appearance of high levels of HDV RNA and antigen in both liver and serum and a high level of viral particles in the serum. A transient suppression of hepatitis B virus replication was evident during the acute phase of HDV infection. Seroconversion for antibodies to delta antigen occurred 3 weeks after the onset of the disease. These results demonstrate that a typical HDV infection can be initiated by inoculation of a susceptible animal with recombinant HDV cDNA.

Seroepidemiology of hepatitis B virus, hepatitis D virus, and human immunodeficiency virus infections among parenteral drug abusers in southern Taiwan

A total of 390 parenteral drug abusers (PDAs) at the Kaohsiung Municipal Narcotics Abstention Institute were examined for markers of hepatitis B virus (HBV), hepatitis D virus (HDV), and human immunodeficiency virus (HIV). All sera were tested for hepatitis B surface antigen (HBsAg), surface antibody (anti-HBs), and core antibody (anti-HBc) by radioimmunoassay (RIA) and for antibody to HIV (anti-HIV) by enzyme-linked immunosorbent assay (ELISA). Hepatitis B e antigen (HBeAg) and antibody to HDV (anti-HDV) were also tested for HBsAg-positive serum samples. Although the HBsAg-positive rate (22.1%) among PDAs was similar to that of the general population in southern Taiwan, the HBV infection rate (99.2%) and the anti-HDV-positive rate (78.5%) among HBsAg-positive subjects were significantly higher than those of the general population in southern Taiwan (P less than 0.0001). None of the PDAs studied were positive for anti-HIV. The levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) among PDAs were significantly higher than those of the general population in southern Taiwan (P less than 0.0001). The more frequent the institutionalisation, the higher the infection rates with HBV and HDV and elevated levels of SGOT and SGPT. Horizontal transmission through parenteral drug abuse may be considered a possible reason for the significantly higher rates of HBV and HDV among parenteral drug abusers.