Hepatitis Delta Virus Genotype Research Articles

The prevalence of HDV among HBsAg-positive populations with and without HIV-1 in China

BackgroundExisting research has provided evidence of changes in hepatitis delta virus (HDV) prevalence worldwide. This study aimed to investigate the prevalence and molecular characteristics of HDV to elucidate its spread in China. MethodsA total of 3,000 samples were collected from 2,241 HBV monoinfections and 759 HBV/HIV-1 coinfections across 13 sites in northern, southern, western, and southwestern China. Serological and virological prevalence were determined by detecting anti-HDV antibodies and HDV RNA. ResultsThe study revealed a 2.63% (95% CI: 2.06–3.21) seroprevalence of HDV among HBV infections in China, exhibiting regional variation. HDV seroprevalence was notably higher at 7.91% (95% CI: 5.98–9.83) in HBV and HIV-1 coinfections. Region and HIV-1 infection were identified as risk factors for HDV infection. Virological prevalence was 0.67% (95% CI: 0.38–0.96) in HBV infections and 2.24% (95% CI: 1.18–3.29) in HBV/HIV-1 coinfections. The predominant HDV genotype in China was HDV-2a, followed by HDV-1. Participants with anti-HDV positivity demonstrated significantly higher proportions of abnormal liver dysfunction and elevated HBV DNA load (P < 0.001) compared to anti-HDV-negative participants. ConclusionsThis study highlights the HDV epidemic in China, sheds light on its geographical distribution and high-risk populations, and provides insights for developing strategies to manage the spread of HDV in the country.

Unbranched rod-like RNA is required for RNA editing of hepatitis delta virus genotype 2 and genotype 4

RNA editing of the hepatitis delta virus (HDV) is essential for generating the large delta antigen, which is crucial for virion assembly. In HDV genotype 1 (HDV-1), editing occurs within the context of the unbranched rod-like structure characteristic of HDV RNA, while RNA editing in HDV-3 requires a branched double-hairpin structure. The regulation of RNA editing in HDV-2 and HDV-4 remains uncertain. Based on predictions of the unbranched rod-like RNA structures of HDV-2 and HDV-4, the editing site occurs as an A.C mismatch pair, surrounded by four base pairs upstream and two base pairs downstream of the editing site, respectively. To investigate HDV-2 and HDV-4 RNA editing, cultured cells were transfected with non-replicating editing reporters carrying wild-type sequences or specific mutations. The results revealed that the editing rates observed for wild-type HDV-2 and HDV-4 were fairly similar, albeit lower than that of HDV-1. Like HDV-1, both HDV-2 and HDV-4 showed a reduction in editing rate when the A.C mismatch pair and the immediately upstream base-paired region were disturbed. Notably, extending the downstream base-paired region from two to three or four (forming a structure identical to that of HDV-1) base pairs increased editing rate. Furthermore, we presented novel evidence that indicates the importance of the first bulge's size, located upstream of the editing site, and the base-pairing length within 7–13 and 28–39 nucleotides downstream of the editing site in influencing the HDV-4 editing rate. To summarize, our analyses suggest that the unbranched rod-like structures surrounding the editing site of HDV-2 and HDV-4 play a crucial role in regulating their RNA editing rates.

Epidemiology and Genetic Diversity of Hepatitis B Virus and Hepatitis Delta Virus Infection in Indigenous Communities in Colombia.

Despite the universal vaccination program, there are still regions and territories with a high prevalence of Hepatitis B Virus infection (HBV), such as the Amazon basin, where several indigenous communities live. Additionally, Hepatitis Delta Virus (HDV) is a defective that requires the hepatitis B surface antigen (HBsAg) for the assembly and release of de novo viral particles. Therefore, hepatitis D could be the result of HBV/HDV coinfection or HDV superinfection in individuals with chronic hepatitis B. Among the high prevalence HDV populations are indigenous communities of America. This study aims to describe and characterize the frequency of HBV and HDV infection, viral genotypes and HBV immune escape mutants in indigenous populations from different regions of Colombia. The diagnosis of hepatitis B and hepatitis D was confirmed by serological markers. Moreover, the HBV and HDV genome were amplified by PCR and RT-PCR, respectively, and, subsequently, the phylogenetic analysis was performed. We characterized 47 cases of chronic hepatitis B, 1 case of reactivation and 2 cases of occult hepatitis B infection (OBI). Furthermore, a high prevalence of HDV infection was identified in the study population (29.33%, 22/75) and the circulation of several HBV genotypes and subgenotypes (F1b, F3, F4, and D). Interestingly, this is the first report of the HDV genotype I circulation in this country. These findings demonstrated that HBV and HDV infections are still public health problems in indigenous communities in Colombia.

Systemic Inflammatory Molecules Are Associated with Advanced Fibrosis in Patients from Brazil Infected with Hepatitis Delta Virus Genotype 3 (HDV-3).

Hepatitis Delta virus (HDV) genotype 3 is responsible for outbreaks of fulminant hepatitis in Northeastern South America. This study investigates if systemic inflammatory molecules are differentially expressed in patients with advanced fibrosis chronically infected with Hepatitis Delta virusgenotype 3(HDV-3). Sixty-one patients from the north of Brazil coinfected with hepatitis B virus (HBV)/HDV-3 were analyzed. HDV quantification and genotyping were performed by semi-nested real-time polymerase chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP) methodologies. Ninety-two systemic inflammatory molecules (SIMs) were measured by Proximity Extension Assay (PEA) technology. The Shapiro-Wilk, Student's t-test, Mann-Whitney tests, and logistic regression analysis were used when appropriate. The median age was 41 years, and all patients were HBeAg negative. Advanced fibrosis or cirrhosis was diagnosed by histological staging in 17 patients, while 44 presented with minimal or no fibrosis. Advanced necroinflammatory activity correlated positively with serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Established non-invasive fibrosis scores (APRI, FIB-4, and AST/ALT ratio) revealed low sensitivities and positive predictive values (PPVs) with an AUROC maximum of 0.586. Among the 92 SIMs analyzed, MCP.4, CCL19, EN.RAGE, SCF, and IL18 showed a positive correlation with fibrosis stage. A combined score including CCL19 and MCP.4 revealed a sensitivity of 81% and an odds ratio of 2.202 for advanced fibrosis. Standard non-invasive fibrosis scores showed poor performance in HDV-3 infection. We here suggest that the determination of CCL19 and MCP.4 may be used to identify patients with advanced fibrosis. Moreover, this study gives novel insights into the immunopathogenesis of HDV-3 infection.

The hepatitis delta virus and chronic hepatitis D.

The hepatitis delta virus and chronic hepatitis D.

Magnitude and genotype of hepatitis delta virus among chronic hepatitis B carriers with a spectrum of liver diseases in Ethiopia

Introduction and ObjectivesChronic hepatitis D infection contributes substantially to the progression of chronic liver disease, especially in most low and middle-income countries, where hepatitis B virus-related chronic liver disease is endemic. Therefore, this study aimed to determine the magnitude and genotype of hepatitis delta virus (HDV) among patients with chronic hepatitis B (CHB)-related liver diseases in Ethiopia. Patients and MethodsIn this cross-sectional study, 323 known HBsAg positive individuals comprising 220 patients with CHB-related liver diseases [121 advanced liver diseases (hepatocellular carcinoma /HCC/ and non-HCC) and 99 chronic hepatitis (CH)], and 103 symptomless blood donors (BD) were enrolled. An ELISA kit was employed to determine HDV infection, and quantitative real-time PCR was used to detect HDV RNA. In addition, a non-coding genomic RNA region was sequenced for genotyping and phylogenetic analysis. ResultsIrrespective of the stage of liver disease, the overall magnitude of HDV was 7.7% (25/323). The frequency of anti-HDV increases with the severity of liver disease, 1.9%, 4%, 10%, and 21.3% among BD, CH, non-HCC, and HCC patients, respectively. HDV RNA has been detected in 1.54 %(5/323) cases with a mean viral load of 4,010,360 IU/ml. All isolates were found to be HDV genotype 1. ConclusionsThe magnitude of HDV infection increased with the severity of liver disease, indicating HDV infection is more common among patients with CHB-related liver diseases in Ethiopia.

Global Distribution and Natural Recombination of Hepatitis D Virus: Implication of Kyrgyzstan Emerging HDVs in the Clinical Outcomes.

Discrepancies in human hepatitis delta virus (HDV) genotypes impact the virus’ biological behavior, clinical manifestation, and treatment response. Herein, this report aims to explore the role of recombination in the worldwide genotypic distribution and genetic diversity of HDV. Three-hundred-forty-eight human HDV full-length genomic sequences of ~1678 nt in length, isolated in twenty-eight countries worldwide between 1986 and 2018, were analysed. Similarity analysis and recombination mapping were performed, and forty-eight recombination events were identified, twenty-nine of which were isolated from Kyrgyzstan and determined to be involved in the diversity and extension of HDV sub-genotypes. HDV recombination occurred only between the genetically close genotypes (genotype 5 and genotype 2) or mainly within genotype 1, suggesting the complex replicative molecular mechanisms of HDV-RNA. The global distribution and classification of HDV genotypes have been updated, indicating that HDV recombination is one of the driving forces behind the biodiversity and the evolution of human HDV genomes. The outcome analysis suggests that the expansion of HDV sub-genotypes and the complex recombination networks might be related to the genomic character of Kyrgyzstan circulating strains and extensive mobility within countries and across borders. These findings will be of great importance in formulating more effective public health HDV surveillance strategies and guiding future molecular and epidemiological research to achieve better clinical outcomes.

Clinical Application of Droplet Digital PCR for Hepatitis Delta Virus Quantification.

Droplet digital PCR (ddPCR) is a novel developed PCR technology providing the absolute quantification of target nucleic acid molecules without the need for a standard curve and regardless PCR amplification efficiency. Our aim was to develop a ddPCR assay for Hepatitis Delta virus (HDV)-RNA viremia quantification and then evaluate its performance in relation to real-time PCR methods. Primers and probe were designed from conserved regions of HDV genome to detect all the 8 HDV genotypes; the World Health Organization (WHO)-HDV international standard was used to calculate the conversion factor transforming results from copies/mL to IU/mL. To evaluate the clinical performance of ddPCR assay, plasma specimens of HDV-infected patients were tested and results were compared with data obtained with two real-time quantitative PCR (RT-qPCR) assays (i.e., in-house assay and commercial RoboGene assay). Analyzing by linear regression a series of 10-fold dilutions of the WHO-HDV International Standard, ddPCR assay showed good linearity with a slope coefficient of 0.966 and R2 value of 0.980. The conversion factor from copies to international units was 0.97 and the quantitative linear dynamic range was from 10 to 1 × 106 IU/mL. Probit analysis estimated at 95% an LOD of 9.2 IU/mL. Data from the evaluation of HDV-RNA in routine clinical specimen of HDV patients exhibited strong agreement with results obtained by RT-qPCR showing a concordance correlation coefficient of 0.95. Overall ddPCR and RT-qPCR showed highly comparable technical performance. Moreover, ddPCR providing an absolute quantification method may allow the standardization of HDV-RNA measurement thus improving the clinical and diagnostic management of delta hepatitis.

Inspecting the Ribozyme Region of Hepatitis Delta Virus Genotype 1: Conservation and Variability.

The hepatitis delta virus (HDV) genome has an autocatalytic region called the ribozyme, which is essential for viral replication. The aim of this study was to use next-generation sequencing (NGS) to analyze the ribozyme quasispecies (QS) in order to study its evolution and identify highly conserved regions potentially suitable for a gene-silencing strategy. HDV RNA was extracted from 2 longitudinal samples of chronic HDV patients and the ribozyme (nucleotide, nt 688–771) was analyzed using NGS. QS conservation, variability and genetic distance were analyzed. Mutations were identified by aligning sequences with their specific genotype consensus. The main relevant mutations were tested in vitro. The ribozyme was conserved overall, with a hyper-conserved region between nt 715–745. No difference in QS was observed over time. The most variable region was between nt 739–769. Thirteen mutations were observed, with three showing a higher frequency: T23C, T69C and C64 deletion. This last strongly reduced HDV replication by more than 1 log in vitro. HDV Ribozyme QS was generally highly conserved and was maintained during follow-up. The most conserved portion may be a valuable target for a gene-silencing strategy. The presence of the C64 deletion may strongly impair viral replication, as it is a potential mechanism of viral persistence.

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.

Clinical evolution of hepatitis delta virus genotype 3 infection in patients from the Western Amazon, Brazil

Background: Chronic infection with the Hepatitis Delta Virus (HDV) is often associated with severe liver decompensation and fulminant hepatitis, but in some cases, it can present a stable clinical presentation. Objectives: This study evaluated the clinical evolution of HDV-3 carriers from an endemic region of the western Brazilian Amazon. Methods: Cross-sectional study was carried out with Anti-HDAg reagent patients, seen at an outpatient clinic specialized in viral hepatitis located in Rondônia, Brazil. Findings: A total of 19 patients, 68.4% male and 31.6% female, aged between 23 and 65 years old, were evaluated; 84.2% were clinically classified as carriers of the decompensated disease and 15.8% as carriers of the inactive disease. The results of the clinical evaluation were related to viral load; 30.8% had detectable viral RNA, and even though it was not possible to establish an association between the stage of the disease and persistent viral replication (p&gt; 0.05), persistent viral replication was predictive of early evolution for liver cirrhosis. Conclusion: The results demonstrate the possibility that viral load can be used as a noninvasive hepatic marker in the clinical management of Hepatitis Delta. Keywords: chronic; hepatitis D; hepatitis delta virus; liver diseases.

The Prevalence and Serological Association of Hepatitis D Virus Genotypes in Taiwan.

Hepatitis Delta Virus (HDV) is an RNA virus that requires the presence of hepatitis B surface antigen (HBsAg) to propagate into hepatocytes, with Genotype I being more prevalent globally. However, the prevalence of HDV genotypes in Taiwan is unknown. Accordingly, a cohort including 24 chronic HBV patients who received nucleos(t)ides (NUCs) between January 2002 and July 2018 was used to determine HDV genotypes and genotype specific serological association in chronic HBV carriers. HDV-positive genotypes in 18/24 (75%) males and 6/24 (25%) females were identified among chronic HBV patients. Viremia was lower in HDV-IV patients than in patients affected with other HDV genotypes (1.34 log10 copies/mL vs. 3.30 log10 copies/mL; p = 0.009). A logistics regression analysis revealed that HDV-IV was inversely proportional to HDV RNA (odds ratio [OR]/95% confidence intervals [CI]: 0.370/0.164–0.830; p = 0.017). The serologic association study indicated lower levels of creatinine (p = 0.047) and HDV-RNA (p = 0.009) in the HDV-IV group than the non-HDV-IV group but did not indicate any significant differences in the AST, ALT, bilirubin levels or other laboratory test factors. The three genotypes evident in Taiwan were HDV-I (4/24, 16.7%), HDV-II (6/24, 25.0%), and HDV-IV (14/24, 58.3%), and HDV-IV is the predominant HDV genotype in Taiwan. These results anticipate a clear understanding of HDV genotype serological association in chronic HBV carriers.

Chronic delta hepatitis: from discovery to new treatments

Introduction. Hepatitis delta virus (HDV) is a small, defective RNA virus that is related more to plant viroids than to other human pathogens. &#x0D; Material and methods. Nearly 50 research articles from various sources were reviewed and a comprehensive analysis was done regarding various parameters concerning HDV. Articles published over a period of 30 years were selected based on their experimental and statistical relevance to HDV. This review gives a brief insight into epidemiology, genetics, clinical evolution and treatment of chronic hepatitis delta.&#x0D; Results. Chronic hepatitis delta remains a major cause of morbidity in Eastern European countries and the Mediterranean region. At the same time, there is a resurgence of HBV and HDV infection in young people (under the age of 50) in Western Europe, as a consequence of the intra-familial and sexual mode of acquisition among immigrants from Eastern Europe, the Mediterranean region and from countries of the former Soviet Union, Africa high burdened regions of Asia and South America. Prevalence among IVDU was found to be higher especially in western european countries and other regions of low HDV prevalence. Chronic delta viral hepatitis is a dynamic, progressive process. A direct cytopathic pattern of liver tissue damage was also observed, especially in the presence of HDV genotype 3. Chronic hepatitis D is reported to progress to cirrhosis and hepatocellular cancer, and this trend is greater the higher the level of HDV viremia at the time of presentation.&#x0D; Conclusions. Flaws in screening and on-time diagnosis still remain due to the insufficient research and data available. While still not classified as a carcinogen by IARC, our review ends up in support of the notion that HDV infection increases the chances and fastens the pathogenic processes leading to HCC.

Predominance of HBV Genotype B and HDV Genotype 1 in Vietnamese Patients with Chronic Hepatitis.

Hepatitis delta virus (HDV) coinfection will additionally aggravate the hepatitis B virus (HBV) burden in the coming decades, with an increase in HBV-related liver diseases. Between 2018 and 2019, a total of 205 HBV patients clinically characterized as chronic hepatitis B (CHB; n = 115), liver cirrhosis (LC; n = 21), and hepatocellular carcinoma (HCC; n = 69) were recruited. HBV surface antigen (HBsAg), antibodies against surface antigens (anti-HBs), and core antigens (anti-HBc) were determined by ELISA. The presence of hepatitis B viral DNA and hepatitis delta RNA was determined. Distinct HBV and HDV genotypes were phylogenetically reconstructed and vaccine escape mutations in the “a” determinant region of HBV were elucidated. All HBV patients were HbsAg positive, with 99% (n = 204) and 7% (n = 15) of them being positive for anti-HBc and anti-HBs, respectively. Anti-HBs positivity was higher among HCC (15%; n = 9) compared to CHB patients. The HBV-B genotype was predominant (65%; n = 134), followed by HBV-C (31%; n = 64), HBV-D, and HBV-G (3%; n = 7). HCC was observed frequently among young individuals with HBV-C genotypes. A low frequency (2%; n = 4) of vaccine escape mutations was observed. HBV-HDV coinfection was observed in 16% (n = 33) of patients with the predominant occurrence of the HDV-1 genotype. A significant association of genotypes with alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzyme levels was observed in HBV monoinfections. The prevalence of the HDV-1 genotype is high in Vietnam. No correlation was observed between HDV-HBV coinfections and disease progression when compared to HBV monoinfections.

HBV/HDV Co-Infection: Epidemiological and Clinical Changes, Recent Knowledge and Future Challenges.

Several investigations have been published on Hepatitis Delta Virus (HDV) infection in recent years, from which we have drawn the salient data to provide readers with useful information to improve their knowledge on the subject. HDV genotypes 5–8 have been recently imported to Western countries from central Africa, whose clinical relevance deserves further investigation. Ongoing HDV replication has been identified as an independent predictor of progression to cirrhosis and HCC for patients with HDV chronic hepatitis (HDV-CH). Long-term treatments of HDV-CH with standard or pegylated interferon alfa (peg-IFN-α) have all been unsatisfactory, leading to a sustained virological response (SVR) only in 20–30% of patients treated, faced with a poor tolerability and frequent serious adverse reactions; the addition of HBV nucleo(s)tide analogues to peg-IFN- α did not improve the rate of SVR. The improved knowledge of the HDV life cycle has allowed the development of direct acting agents towards key-points of the HDV life cycle, namely bulevirtide, lonafarnib and nucleic acid polymers. Preliminary data have shown that these drugs are more effective than interferon-based therapies, but adverse reactions are also common, which however seem toned down in combination therapy with other antivirals.

Molecular epidemiology and clinical characteristics of hepatitis delta virus (HDV) infected patients with elevated transaminases in Shanghai, China

BackgroundPatients coinfected with HBV and hepatitis D virus (HDV) have a greater risk of HCC and cirrhosis. The current study was undertaken to assess HDV genotype distribution and determine clinical characteristics of hepatitis delta virus (HDV) among HBsAg positive individuals in Shanghai.MethodThis retrospective study involved 225 serum samples from HBsAg positive hospitalized patients from October 2010 to April 2013. HDV-specific RT-nested PCR was used to amplify HDV RNA. HDV genotypes were characterized by Next-generation sequencing (NGS), followed by phylogenetic analyses. HDV/HBV co-infected patients and HBV mono-infected patients were compared clinically and virologically.ResultsOut of the 225 HBsAg-positive serum samples with elevated transaminases, HDV-RNA was identified in 11 (4.9%) patients. The HBV loads in the HDV positive group were significantly lower than the HDV negative HBV-infected patients. The aminotransferase enzymes were significantly higher in HDV/HBV co-infected compared to HDV negative patients (P < 0.05). Phylogenetic analyses indicated that HDV-2 genotype being the predominant genotype, other HDV genotypes were not observed. HDV/HBV patients were significantly associated with a rather unfavourable clinical outcome.ConclusionIn summary, the prevalence of HDV infection in patients with elevated transaminases is not low and the predominance of HDV genotype 2 infection in Shanghai. This finding helps us to better understand the correlation of HDV/HBV co-infection. Moreover, Next-generation sequencing (NGS) technologies provide a rapid, precise method for generating HDV genomes to define infecting genotypes.

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

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. 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. 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. Place of birth, HDV genotype and persistent viremia constitute the main determinants of liver involvement and response to treatment in chronic HDV-infected patients. 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.

Hepatitis delta genotype 5 is associated with favourable disease outcome and better response to treatment compared to genotype 1

Coinfection with HDV causes rapid progression to liver cirrhosis and hepatic decompensation in patients with chronic hepatitis B. Factors that are associated with disease progression are poorly understood. In this study we aim to identify risk factors associated with disease progression and better characterise clinical differences and treatment response between HDV genotype 1 and5. In this retrospective study, all patients under our care between 2005 and 2016 with HBV/HDV coinfection (HBsAg+, anti-HDV antibodies positive) were analysed. Patients were excluded if follow-up was less than 6 months, if they had HCV and/or HIV coinfection or an acute HDV infection. Demographic data, stage of liver disease, development of liver complications and treatment response were recorded. One-hundred seven patients (mean age 36.0 years, 57% male) were followed for a median period of 4.4 years (range 0.6-28.1 years); 64% were of African origin and 17% were of European origin, with 28% of patients being cirrhotic at first visit; 43% patients had actively replicating HDV virus (anti-HDV-IgG+, anti-HDV-IgM+ or HDV RNA+) and 57% of patients were HDV exposed (anti-HDV-IgG+, HDV RNA-). Patients with actively replicating HDV more often developed liver complications than HDV-exposed patients (p= 0.002), but no differences in baseline characteristics were observed. Patients with HDV genotype 5 less often developed cirrhosis or hepatic decompensation compared to patients with HDV genotype 1. Twenty-four patients were treated with peg-IFN and post-treatment response was significantly better in patients infected with genotype 5 (10% GT1 vs. 64% GT5, p= 0.013). Patients infected with HDV genotype 5 appear to have a better prognosis with fewer episodes of hepatic decompensation and better response to peg-IFN treatment than patients infected with HDV genotype1. Hepatitis delta is a virus that affects the liver. The virus is known to have different subtypes, called genotypes. With this research we discovered that hepatitis delta virus genotype 1 behaves differently than genotype 5 and causes faster development of liver disease. This is important for education of our patients and to determine how often we need to check our patients.

Structural Pattern Differences in Unbranched Rod-like RNA of Hepatitis Delta Virus affect RNA Editing.

Hepatitis delta virus (HDV) RNA forms an unbranched rod-like structure and complexes with the delta antigen (HDAg). Host ADAR1-catalyzed RNA editing at the amber/W site of the small HDAg leads to the production of the large HDAg, which inhibits replication and is required for virion assembly. For HDV genotype 1, amber/W editing is controlled by HDAg and the RNA structure immediate vicinity and downstream of the editing site. Here, the effects of 20 mutants carrying an increased length of consecutive base-pairing at various sites in HDV RNA on amber/W site editing were examined. All nine mutants carrying genomic regions that formed up to 15 consecutive base pairs, which is also the maximum length observed in 41 naturally occurring HDV genomes, showed normal editing rate. However, mutants carrying a 16 or 17 consecutive base-paired antigenomic segment located as far as 114 nt upstream could increase editing efficiency, possibly by interfering with HDAg binding. These data show for the first time that extended base-pairing upstream of the amber/W site could increase HDV RNA editing efficiency. Furthermore, it appears that the naturally occurring HDV RNA structures have been selected for suboptimal amber/W RNA editing, which favors the HDV replication cycle.

Characterization of Hepatitis Delta Virus Among Pregnant Women of Pakistan

Hepatitis delta virus (HDV) is a highly pathogenic virus and causes rapid disease progression from fulminant hepatitis to development of hepatocellular carcinoma in patients infected with hepatitis B virus (HBV). HDV is endemic in Pakistan; however, there are no available data on HDV prevalence among the high-risk group of HBV-infected pregnant women. A total of 1,394 pregnant women, visiting different public-sector hospitals in Lahore, were enrolled in this study. Their demographic data and blood samples were collected from May 2016 to July 2017. Samples were screened for both HBsAg and anti-HDV. Anti-HDV positive samples were tested for HDV RNA, and samples positive for HDV RNA were further sequenced to determine the HDV genotype. Of the 1,394 samples, HBsAg was positive in 63 (4.5%). Of these 63 HBsAg-positive samples, 13 (20.63%) were positive for anti-HDV. Of the 13 HBsAg/anti-HDV positive samples, HDV RNA was detected in 4 (30.8%) samples and all 4 carried HDV genotype 1. The age of enrolled women varied from 20 to 40 years, with most of the women living in urban areas, having education more than secondary school level, belonging to middle class, and being housewives. Majority of the tested women were of age from 25 to 30 years (39.2%); however, the prevalence of HBV was higher in age group 31-35 years (10.7%, confidence interval [CI]: 4.73-16.67); however, anti-HDV prevalence was 1.9% (CI: -0.7 to 4.7). This study is the first report on HDV prevalence among pregnant women in Pakistan. Our study showed a high predominance of HDV (20.63%) in HBV-infected pregnant women and the prevalence of HDV genotype 1 infection. The findings contribute to a better understanding of the HDV/HBV coinfection among pregnant women and circulating HDV genotypes in the country.