Hepatitis D: A Review.

Importance: Hepatitis D virus (HDV) infection occurs in association with hepatitis B virus (HBV) infection and affects approximately 12 million to 72 million people worldwide. HDV causes more rapid progression to cirrhosis and higher rates of hepatocellular carcinoma than HBV alone or hepatitis C virus. Observations: HDV requires HBV to enter hepatocytes and to assemble and secrete new virions. Acute HDV-HBV coinfection is followed by clearance of both viruses in approximately 95% of people, whereas HDV superinfection in an HBV-infected person results in chronic HDV-HBV infection in more than 90% of infected patients. Chronic hepatitis D causes more rapidly progressive liver disease than HBV alone. Approximately 30% to 70% of patients with chronic hepatitis D have cirrhosis at diagnosis and more than 50% die of liver disease within 10 years of diagnosis. However, recent studies suggested that progression is variable and that more than 50% of people may have an indolent course. Only approximately 20% to 50% of people infected by hepatitis D have been diagnosed due to lack of awareness and limited access to reliable diagnostic tests for the HDV antibody and HDV RNA. The HBV vaccine prevents HDV infection by preventing HBV infection, but no vaccines are available to protect those with established HBV infection against HDV. Interferon alfa inhibits HDV replication and reduces the incidence of liver-related events such as liver decompensation, hepatocellular carcinoma, liver transplant, or mortality from 8.5% per year to 3.3% per year. Adverse effects from interferon alfa such as fatigue, depression, and bone marrow suppression are common. HBV nucleos(t)ide analogues, such as entecavir or tenofovir, are ineffective against HDV. Phase 3 randomized clinical trials of bulevirtide, which blocks entry of HDV into hepatocytes, and lonafarnib, which interferes with HDV assembly, showed that compared with placebo or observation, these therapies attained virological and biochemical response in up to 56% of patients after 96 weeks of bulevirtide monotherapy and 19% after 48 weeks of lonafarnib, ritonavir, and pegylated interferon alfa treatment. Conclusions and Relevance: HDV infection affects approximately 12 million to 72 million people worldwide and is associated with more rapid progression to cirrhosis and liver failure and higher rates of hepatocellular carcinoma than infection with HBV alone. Bulevirtide was recently approved for HDV in Europe, whereas pegylated interferon alfa is the only treatment available in most countries.

Diagnosis of HDV: From virology to non-invasive markers of fibrosis.

Hepatitis D viral infection in humans is a disease that requires the establishment of hepatitis B, relying on hepatitis B surface Ag and host cellular machinery to replicate and propagate the infection. Since its discovery in 1977, substantial progress has been made to better understand the hepatitis D viral life cycle, pathogenesis and modes of transmission along with expanding on clinical knowledge related to prevention, diagnosis, monitoring and treatment. The availability of serologic diagnostic assays for hepatitis D infection has evolved over time with current widespread availability, improved detection and standardized reporting. With human migration, the epidemiology of hepatitis D infection has changed over time. Thus, the ability to use diagnostic assays remains essential to monitor the global impact of hepatitis D infection. Separately, while liver biopsy remains the gold standard for the staging of this rapidly progressive and severe form of chronic viral hepatitis, there is an unmet need for clinical monitoring of chronic hepatitis D infection for management of progressive disease. Thus, exploration of the utility of non-invasive fibrosis markers in hepatitis D is ongoing. In this review, we discuss the virology, the evolution of diagnostics and the development of non-invasive markers for the detection and monitoring of fibrosis in patients with hepatitis D infection.

What does quantitative HBsAg level mean in chronic hepatitis D infection?

OBJECTIVE: In hepatitis delta virus (HDV) infection, which is an important etiological cause of chronic liver disease, the relationship between serum quantitative HBsAg level and fibrosis and histological activity was investigated. METHODS: Between 2014 and 2020, 98 patients with chronic HDV infection (53 noncirrhotic, 45 cirrhotic) participated in this prospectively designed study. Quantitative HBsAg levels of the patients were measured and their relationship with the stage of chronic liver disease was compared with histological activity index (HAI), fibrosis score and HDV RNA, model for end-stage liver disease score and other biochemical parameters. RESULTS: All patients were infected with genotype 1 (100%). HBeAg was positive in 8 (8.1%) of the patients. A correlation was found between quantitative HBsAg level and HDV RNA level in patients with both cirrhotic (r = 0.568; P < 0.001) and noncirrhotic (r = 0.644; P < 0.001) HDV infection. Alanine transaminase (P = 0.001; r = 0.495) and aspartate transaminase (P = 0.001; r = 0.511) levels correlated with quantitative HBsAg levels, more prominently in noncirrhotic patients. There was a correlation between quantitative HBsAg level and histological activity index (HAI) in patients with noncirrhotic HDV infection (P < 0.001; r = 0.664). In receiver operating characteristic analysis, both quantitative HBsAg (for cutoff: 1000; sensitivity 76%; specificity 17%; P = 0.335) and HDV RNA (for cutoff: 100000; sensitivity 2%; specificity 98%; P = 0.096) were not predictive markers for cirrhosis. CONCLUSION: Quantitative HBsAg level can be evaluated as an indicator of viral replication and histological activity in patients with chronic delta hepatitis without cirrhosis. We think that quantitative HBsAg level will be useful in the management of chronic HDV infection, especially in noncirrhotic patients.

Shear wave elastography: How well does it perform in chronic hepatitis D virus infection?

Hepatitis delta virus (HDV) infection is associated with accelerated progression of liver disease to cirrhosis. Shear wave elastography (SWE) is a non-invasive evaluation method of liver fibrosis. Its performance in accurately characterizing HDV fibrosis compared to other noninvasive markers remains unknown. We assessed the performance of SWE in patients with chronic HDV, Hepatitis B (HBV) and Hepatitis C (HCV) infection. Cirrhosis was determined by histology or clinical data. Area under receiver operator characteristics (AUROC) was used to assess diagnostic performance in identifying cirrhosis by SWE in comparison with Fibroscan® (VCTE) and serologic tests of fibrosis. 158 patients with chronic hepatitis (HDV:44%, HBV: 46% and HCV: 29%) were evaluated. Cirrhosis was diagnosed in 28 (17.7%) patients. Mean noninvasive fibrosis measurements for the HBV/HCV and HDV groups, respectively, were as follows: APRI: 0.73 ± 1.08 and 1.3 ± 1.38; FIB-4: 1.90 ± 2.24 and 2.33 ± 2.24; VCTE: 8.9 ± 6.7 kPa vs 10.4 ± 5.3 kPa; SWE: 1.5 ± 0.2 m/s and 1.6 ± 0.2 m/s. The performance of SWE in detecting HDV-induced cirrhosis (AUROC 0.84, 95% CI 0.71-0.97) was slightly lower than in HBV/HCV induced disease (AUROC 0.88, 95% CI 0.81-0.96). For HDV patients, the performance of SWE was comparable to VCTE and slightly better than APRI and FIB-4 especially in APRI and FIB-4 indeterminate zones. The overall less accurate performance of noninvasive markers in HDV in comparison with HBV and HCV may be a result of significant hepatic inflammation in HDV.

HBsAg isoform dynamics during NAP-based therapy of HBeAg-negative chronic HBV and HBV/HDV infection.

Nucleic acid polymers block the assembly of hepatitis B virus (HBV) subviral particles, effectively preventing hepatitis B surface antigen (HBsAg) replenishment in the circulation. Nucleic acid polymer (NAP)-based combination therapy of HBV infection or HBV/hepatitis D virus (HDV) co-infection is accompanied by HBsAg clearance and seroconversion, HDV-RNA clearance in co-infection, and persistent functional cure of HBV (HBsAg < 0.05 IU/ml, HBV-DNA target not dected, normal alanine aminotransferase) and persistent clearance of HDV RNA. An analysis of HBsAg isoform changes during quantitative HBsAg declines (qHBsAg), and subsequent treatment-free follow-up in the REP 301/REP 301-LTF (HBV/HDV) and REP 401 (HBV) studies was conducted. HBsAg isoforms were analyzed from frozen serum samples using Abbott Research Use Only assays for HBsAg isoforms (large [L], medium [M], and total [T]). The relative change over time in small HBsAg relative to the other isoforms was inferred by the change in the ratio over time of T-HBsAg to M-HBsAg. HBsAg isoform declines followed qHBsAg declines in all participants. No HBsAg isoforms were detectable in any participants with functional cure. HBsAg declines > 2 log10 IU/ml from baseline were correlated with selective clearance of S-HBsAg in 39 of 42 participants. Selective S-HBsAg decline was absent in 9 of 10 participants with HBsAg decline < 2 log10 IU/ml from baseline. Mild qHBsAg rebound during follow-up <10 IU/ml consisted mostly of S-HBsAg and M-HBsAg and not accompanied by significant covalently closed circular DNA activity. Conclusion: The faster observed declines in S-HBsAg indicate the selective clearance of subviral particles from the circulation, consistent with previous mechanistic studies on NAPs. Trace HBsAg rebound in the absence of HBV DNA may reflect HBsAg derived from integrated HBV DNA and not rebound of viral infection.

A Rapid Point-of-Care Test for the Serodiagnosis of Hepatitis Delta Virus Infection.

Hepatitis Delta virus (HDV) is a satellite of the Hepatitis B virus (HBV) and causes severe liver disease. The estimated prevalence of 15-20 million infected people worldwide may be underestimated as international diagnostic guidelines are not routinely followed. Possible reasons for this include the limited awareness among healthcare providers, the requirement for costly equipment and specialized training, and a lack of access to reliable tests in regions with poor medical infrastructure. In this study, we developed an HDV rapid test for the detection of antibodies against the hepatitis delta antigen (anti-HDV) in serum and plasma. The test is based on a novel recombinant large hepatitis delta antigen that can detect anti-HDV in a concentration-dependent manner with pan-genotypic activity across all known HDV genotypes. We evaluated the performance of this test on a cohort of 474 patient samples and found that it has a sensitivity of 94.6% (314/332) and a specificity of 100% (142/142) when compared to a diagnostic gold-standard ELISA. It also works robustly for a broad range of anti-HDV titers. We anticipate this novel HDV rapid test to be an important tool for epidemiological studies and clinical diagnostics, especially in regions that currently lack access to reliable HDV testing.

Liver-Resident Bystander CD8+ T Cells Contribute to Liver Disease Pathogenesis in Chronic Hepatitis D Virus Infection.

BACKGROUND & AIMS: The hepatitis D virus (HDV) causes the most severe form of chronic hepatitis, often progressing to cirrhosis within 5 to 10 years. There is no curative treatment, and the mechanisms underlying the accelerated liver disease progression are unknown. METHODS: Innate and adaptive immune responses were studied in blood and liver of 24 patients infected with HDV and 30 uninfected controls by multiparameter flow cytometry in correlation with disease severity and stage. RESULTS: The 2 main intrahepatic innate immune-cell populations, mucosal-associated invariant T cells and natural killer (NK) cells, were reduced in the livers of patients infected with HDV compared with those of uninfected controls but were more frequently activated in the liver compared with the blood. Most intrahepatic cluster of differentiation (CD) 8-positive (CD8+) T cells were memory cells or terminal effector memory cells, and most of the activated and degranulating (CD107a+) HDV-specific and total CD8+ T cells were liver-resident (CD69+C-X-C motif chemokine receptor 6+). Unsupervised analysis of flow cytometry data identified an activated, memory-like, tissue-resident HDV-specific CD8+ T-cell cluster with expression of innate-like NK protein 30 (NKp30) and NK group 2D (NKG2D) receptors. The size of this population correlated with liver enzyme activity (r = 1.0). NKp30 and NKG2D expression extended beyond the HDV-specific to the total intrahepatic CD8+ T-cell population, suggesting global bystander activation. This was supported by the correlations between (i) NKG2D expression with degranulation of intrahepatic CD8+ T cells, (ii) frequency of degranulating CD8+ T cells with liver enzyme activity and the aspartate aminotransferase-to-platelet ratio index score, and by the in vitro demonstration of cytokine-induced NKG2D-dependent cytotoxicity. CONCLUSION: Antigen-nonspecific activation of liver-resident CD8+ T cells may contribute to inflammation and disease stage in HDV infection.

Origin, HDV genotype and persistent viremia determine outcome and treatment response in patients with chronic hepatitis delta.

BACKGROUND & AIMS: HDV infection causes severe chronic liver disease in individuals infected with HBV. However, the factors associated with poor prognosis are largely unknown. Thus, we aimed to identify prognostic factors in patients with HDV infection. METHODS: The French National Reference Centre for HDV performed a nationwide retrospective study on 1,112 HDV-infected patients, collecting epidemiological, clinical, virological and histological data from the initial referral to the last recorded follow-up. RESULTS: The median age of our cohort was 36.5 (29.9-43.2) years and 68.6% of our cohort were male. Most patients whose birthplace was known were immigrants from sub-Saharan Africa (52.5%), southern and eastern Europe (21.3%), northern Africa and the Middle East (6.2%), Asia (5.9%) and South America (0.3%). Only 150 patients (13.8%) were French native. HDV load was positive in 659 of 748 tested patients (88.1%). HDV-1 was predominant (75.9%), followed by sub-Saharan genotypes: HDV-5 (17.6%), HDV-7 (2.9%), HDV-6 (1.8%) and HDV-8 (1.6%). At referral, 312 patients (28.2%) had cirrhosis, half having experienced at least 1 episode of hepatic decompensation. Cirrhosis was significantly less frequent in African than in European patients regardless of HDV genotype. At the end of follow-up (median 3.0 [0.8-7.2] years), 48.8% of the patients had developed cirrhosis, 24.2% had ≥1 episode(s) of decompensation and 9.2% had hepatocellular carcinoma. European HDV-1 and African HDV-5 patients were more at risk of developing cirrhosis. Persistent replicative HDV infection was associated with decompensation, hepatocellular carcinoma and death. African patients displayed better response to interferon therapy than non-African patients (46.4% vs. 29.1%, p <0.001). HDV viral load at baseline was significantly lower in responders than in non-responders. CONCLUSION: Place of birth, HDV genotype and persistent viremia constitute the main determinants of liver involvement and response to treatment in chronic HDV-infected patients. LAY SUMMARY: Chronic liver infection by hepatitis delta virus (HDV) is the most severe form of chronic viral hepatitis. Despite the fact that at least 15-20 million people are chronically infected by HDV worldwide, factors determining the severity of liver involvement are largely unknown. By investigating a large cohort of 1,112 HDV-infected patients followed-up in France, but coming from different areas of the world, we were able to determine that HDV genotype, place of birth (reflecting both viral and host-related factors) and persistent viremia constitute the main determinants of liver involvement and response to treatment.

Long-term clinical outcomes in patients with chronic hepatitis delta: the role of persistent viraemia.

BACKGROUND: Chronic hepatitis delta is a severe liver disease with rapid progression to cirrhosis. The impact of hepatitis delta virus (HDV)-RNA on disease progression and interferon treatment in a real-world cohort has been barely explored. AIM: To assess the development of clinical events in a cohort of chronic hepatitis delta patients according to the presence or absence of HDV-RNA METHODS: Multicentre study at four academic hospitals in Spain included anti-HDV-positive patients with compensated liver disease with a follow-up ≥12 months. RESULTS: Among 2888 HBsAg-positive subjects, 151 (5.2%) tested positive for anti-HDV, and 118 were included (58% men; median age, 49 years; 73% detectable HDV-RNA and 30% cirrhosis, most often in subjects with HDV-RNA). After a median follow-up of 8 years, subjects with initially detectable HDV-RNA were more prone to developing cirrhosis (31% vs 0%, P = .002) and/or liver decompensation (28% vs 3%, P = .019). Mortality rate was 0.44 per 1000 person-months. The probability of a clinical event was 6%, 25%, and 80% according to initial baseline-event-anticipation score. HDV-RNA became undetectable in 21 (24%) subjects either due to interferon or spontaneously (48% vs 52%, P = .29). Liver decompensation was reduced in interferon-treated patients (13% vs 38%, P = .026). CONCLUSIONS: Subjects with persistently positive HDV-RNA had a worse prognosis in terms of clinical events. Baseline-event-anticipation score is useful in predicting the risk of developing liver decompensation and hepatocellular carcinoma. Interferon was beneficial in reducing liver decompensation, even in the absence of virological response.

Vibration-controlled transient elastography for the detection of cirrhosis in chronic hepatitis D infection.

Noninvasive detection of cirrhosis via vibration-controlled transient elastography (VCTE) has revolutionized the management of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. However, VCTE has not been studied in chronic hepatitis D virus (HDV) infection and accuracy remains in question due to the significant hepatic inflammation associated with this infection. Consecutive HBV, HCV and HDV patients who underwent VCTE (2006-2019) were evaluated. Diagnosis of cirrhosis was made via liver biopsy or clinical findings. VCTE was compared with other noninvasive serum fibrosis tests using AUROC curves. The performance of VCTE in HBV/HCV/HDV was also compared. We evaluated 319 patients (HBV-112; HCV-132; HDV-75), 278(87%) patients had histology for evaluation. HDV patients had evidence of higher hepatic inflammation as evidence by aspartate aminotransferase, alanine aminotransferase and histology activity index. Cirrhotic HDV patients had higher mean liver stiffness measurements compared with noncirrhotic patients (29.0 vs 8.3 kPa, P < .0001). VCTE demonstrated excellent diagnostic accuracy for the detection of cirrhosis with an AUROC of 0.90 compared with APRI (0.83), FIB-4 (0.88), AAR (0.73) and RPR (0.85). Performance of VCTE in HDV was comparable with HBV (0.93) and HCV (0.94). At the optimized cut-off value of ≥14.0 kPa for determining cirrhosis in HDV, VCTE had a sensitivity of 0.78, specificity of 0.86, NPV of 0.93 and PPV of 0.64. Hence, VCTE is a useful noninvasive test in HDV for determining cirrhosis despite the presence of significant hepatic inflammation.

The Delta-4 fibrosis score (D4FS): A novel fibrosis score in chronic hepatitis D.

BACKGROUND: Chronic Hepatitis D virus (HDV) infection results in the most severe form of viral hepatitis with a rapid progression to cirrhosis. However, non-invasive fibrosis tests that can accurately predict cirrhosis have not been adequately validated. We aimed to develop a clinically useful non-invasive score that can accurately detect cirrhosis. MATERIAL AND METHODS: Patients with chronic HDV diagnosed by liver histology or serum PCR were evaluated. Data regarding demographics, laboratory, imaging, vibration-controlled transient elastography (VCTE), and liver biopsy were collected. The total cohort was randomized into a training and validation cohort. The training cohort was used to develop a novel score, the Delta-4 fibrosis score (D4FS) which was then compared to other non-invasive tests in the validation cohort by area under receiver operating characteristics (AUROC). RESULTS: 77 patients with chronic HDV were evaluated: mean age 42.6 (SD:11.1) years, 59.7% male, and 57.1% Asian. The total cohort was then separated into a training (n = 45) and validation (n = 32) cohort with no significant differences in terms of clinical characteristics between the two. From the training cohort, the D4FS was derived from variables of statistical and clinical interest (gamma-glutamyl transpeptidase (GGT), platelet count, alanine aminotransferase (ALT), and liver stiffness measurement (LSM)). The D4FS demonstrated the best AUROC in the validation cohort (0.94) followed by VCTE (0.90), FIB-4 (0.86), APRI (0.81), and AAR (0.71). DISCUSSION: The D4FS is a clinically useful non-invasive fibrosis score that can accurately detect cirrhosis in patients with chronic HDV infection. Further studies should be performed to further validate clinical utility.

HBV/HDV Coinfection: A Challenge for Therapeutics.

Chronic hepatitis D (CHD) results from an infection with the hepatitis B virus and hepatitis D virus (HDV). CHD is the most severe form of human viral hepatitis. Current treatment options consist of interferon alfa, which is effective only in a minority of patients. Study of HDV molecular virology has resulted in new approaches entering clinical trials, with phase-3 studies the most advanced. These include the entry inhibitor bulevirtide, the nucleic acid polymer REP 2139-Ca, the farnesyltransferase inhibitor lonafarnib, and pegylated interferon lambda. This article summarizes the available data on these emerging therapeutics.

Targeting Hepatitis D.

New therapeutic strategies to treat chronic hepatitis D are directed to deprive the hepatitis D virus (HDV) of functions necessary to complete its life cycle that are provided by the hepatitis B virus (HBV) and by the host. Current options are (1) the block by the synthetic peptide Myrcludex B of HBV surface antigen (HBsAg) entry into cells through the inhibition of the sodium taurocholate cotransporting receptor; (2) the inhibition with lonafarnib of the farnesylation of the large HD antigen, required for virion assembly; (3) the presumed reduction by the nucleic acid polymer REP 2139 of the release of the HBsAg and subviral HBV particles necessary for HD virion morphogenesis. Lonafarnib and Myrcludex in monotherapy reduced serum HDV-RNA but did not reduce the HBsAg and HD viremia rebounded after therapy; they may provide additional efficacy to pegylated interferon alpha (Peg IFN-α) therapy. Treatment with REP-2139 in combination with Peg IFN-α induced a sustained clearance both of the HDV-RNA and HBsAg in 5 of 12 patients, providing the best interim results so far obtained in the therapy of chronic hepatitis D.

A Case Report of Hepatocellular Carcinoma 5 Years After HBsAg Loss in Chronic Hepatitis Delta: How Long Surveillance is Required?

BACKGROUND: Hepatitis delta virus infection occurs as acute co-infection or as superinfection in patients with preexisting chronic hepatitis B. Chronic hepatitis delta leads to more severe disease than chronic hepatitis B, with more rapid progression of fibrosis and increased risk of hepatocelullar carcinoma. CASE REPORT: We report a case of hepatocelullar carcinoma 5 years after spontaneous clearance of Hepatitis B surface antigen in a patient with previous chronic hepatitis delta. He had been diagnosed with acute hepatitis delta superinfection 30 years ago which evolved to chronic delta infection and subsequently development of liver cirrhosis. Despite no specific antiviral treatment, he lost HBsAg persistently with later regression of cirrhosis. CONCLUSIONS: In patients with cirrhosis due to chronic hepatitis delta who cleared HBsAg with improvement of liver fibrosis by non invasive techniques, it remains unknown how long hepatocelullar carcinoma surveillance has to be maintained.

Noninvasive markers for staging fibrosis in chronic delta hepatitis.

BACKGROUND: Serum fibrosis markers are useful in staging chronic hepatitis B (HBV) and C (HCV) virus but have not been evaluated in chronic hepatitis D virus (HDV). AIM: To evaluate the utility of serum fibrosis markers [fibrosis-4 score (FIB-4), aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio, aspartate aminotransferase ratio (AAR), age-platelet index (API), AST-to-platelet-ratio-index (APRI) and Hui score] in HDV infection. METHODS: Clinical and histologic laboratory data from HBV, HCV and HDV patients were evaluated and serum fibrosis markers were calculated. The ability of fibrosis markers to detect advanced fibrosis (Ishak ≥4) and cirrhosis (Ishak = 6) were evaluated and compared between viral infections. RESULTS: A total of 1003 subjects (HCV = 701, HBV = 240 and HDV = 62) with mean age of 46 ± 11 and 66% male were evaluated. HDV subjects had higher ALT and AST than HCV and lower platelets than both HBV and HCV. Histologically, HDV had the greatest percentage of Ishak ≥4 and necroinflammation. FIB-4 performed best in detecting advanced fibrosis and cirrhosis in all viral cohorts. In HDV, area under the receiver operator curve (AUROC) 95% confidence intervals for detecting advanced fibrosis were: FIB-4 = 0.70 (0.55-0.84), API = 0.69 (0.55-0.82), APRI = 0.68 (0.54-0.82), Hui score = 0.63 (0.49-0.78), AAR = 0.63 (0.48-0.77). The AUROC for detecting cirrhosis in HDV were: FIB-4 = 0.83 (0.69-0.97), API = 0.80 (0.66-0.95), APRI = 0.75 (0.61-0.89), Hui score = 0.70 (0.49-0.91) and AAR = 0.70 (0.48-0.93). Adjustment of published cut-offs led to marginal improvements in FIB4 for advanced fibrosis and of APRI for cirrhosis in HDV. CONCLUSIONS: Serum fibrosis markers have lower performance accuracy in chronic HDV infected patients compared to HBV and HCV patients. Other noninvasive fibrosis markers should be explored to assist in the management of these patients.

Chronic Hepatitis B, C, and D.

Chronic hepatitis B, C, and D virus infections contribute significantly to the morbidity and mortality of immunocompromised individuals. To contextualize discussion of these infections in immunocompromised patients, this paper provides an overview of aspects of infection in normal hosts. It then describes differences in disease, diagnostic testing, and therapeutic management observed in immunocompromised patients.

HBsAg kinetics in chronic hepatitis D during interferon therapy: on-treatment prediction of response.

BACKGROUND: Therapy of chronic hepatitis D with Interferon is successful when testing for HDV-RNA turns negative. This end-point is disputed. AIM: To assess the role of serum hepatitis B surface antigen (HBsAg) in the clearance of HDV-RNA in pegylated interferon (Peg-IFN)-treated chronic hepatitis D (CHD). METHODS: Sixty-two patients with CHD, treated with Peg-IFN, were considered. The patients belonged to three groups: 14 patients cleared the HBsAg and HDV-RNA (responders, R), 12 cleared the HDV-RNA remaining positive for HBsAg (partial responders, PR) and 36 cleared neither the HBsAg nor the HDV-RNA (nonresponders, NR). RESULTS: In responders, at baseline the median value (mv) of HBsAg and HDV-RNA was 1187 and 188 663 IU/mL. By month 6 of therapy, HBsAg declined to less than 1000 IU/mL and HDV-RNA was undetectable in 12 patients. In NR, the pre-therapy median value of HBsAg and HDV viremia was 6577 and 676 319 IU/mL. There was no significant reduction of antigen at month 6; after a decline, HDV-RNA rebounded to baseline levels. In PR, the median value of baseline HBsAg was 7031 IU/mL; it declined at month 6 in the majority. HDV-RNA progressively declined from an initial median value of 171 405 IU/mL. HBsAg <1000 IU/mL at month 6 discriminated responders and PR from NR (P < 0.001). By ROC curve, the threshold of 0.105 log reduction of HBsAg associated with 1.610 log reduction of HDV-RNA from baseline to month 6 predicted the clearance of this marker. CONCLUSIONS: A reduction of serum HBsAg is mandatory for the definitive clearance of the HDV-RNA. Quantitative HBsAg may predict the long-term response to Peg-IFN therapy and provide a guide to prolong or stop treatment.

Hepatitis B and D viruses replication interference: Influence of hepatitis B genotype.

AIM: To study the hepatitis B virus (HBV) and hepatitis D virus (HDV) replication interferences in patients with chronic hepatitis delta infected with different HBV genotypes. METHODS: We conducted a transversal study including 68 chronic hepatitis delta (CHD) (37 HIV-positive) patients and a control group of 49 chronic hepatitis B (CHB) (22 HIV-positive) patients. In addition, a dynamic follow-up was performed in 16 CHD patients. In all the samples, the surface antigen of hepatitis B (HBsAg) serum titers were analyzed with the Monolisa HBsAg Ultra system (Bio-Rad), using as quantification standard a serial dilution curve of an international HBsAg standard. Serum HBV-DNA titers were analyzed using the Roche Cobas TaqMan (Roche, Barcelona, Spain), and the serum HDV-RNA using an in-house real-time qRT-PCR method, with TaqMan probes. HBV genotype was determined with the line immunoassay LiPA HBV genotyping system (Innogenetics, Ghent, Belgium). In those patients negative for LiPA assay, a nested PCR method of complete HBsAg coding region, followed by sequence analysis was applied. RESULTS: No differences in the HBV-DNA levels were found in CHB patients infected with different HBV genotypes. However, in CHD patients the HBV-DNA levels were lower in those infected with HBV-A than in those with HBV-D, both in HIV negative [median (IQR): 1.25 (1.00-1.35) vs 2.95 (2.07-3.93) log10 (copies/mL), P = 0.013] and HIV positive patients [2.63 (1.24-2.69) vs 7.25 (4.61-7.55) log10 (copies/mL), P < 0.001]. This was confirmed in the dynamic study of the HBV/HDV patients. These differences induce an under-estimation of HBV-A incidence in patients with CHD analyzed with LiPA assay. Finally, the HBsAg titers reflected no significant differences in CHD patients infected with HBV-A or D. CONCLUSION: Viral replication interference between HBV and HDV is HBV-genotype dependent, and more evident in patients infected with HBV-genotype A, than with HBV-D or E.