Compartmentalization of hepatitis B virus: Looking beyond the liver

Burden, Outcome, and Comorbidities of Extrahepatic Manifestations in Hepatitis B Virus Infections

Hepatitis B virus (HBV) infections affect approximately 296 million people around the world, and the prevalence of any past or present HBV infection during the years 2015-2018 was as high as 4.3%. Acute HBV infection often presents with nonspecific symptoms and is usually self-limited, but 5% of patients can have persistent infections leading to chronic HBV infection and the risk of turning into chronic HBV infection is significantly higher in babies with vertical transmission (95%). Patients with chronic HBV infection are usually asymptomatic, but 15 to 40% of chronic HBV carriers develop cirrhosis and/or hepatocellular carcinoma. In addition to liver-related disorders, HBV is also associated with several extrahepatic complications, including glomerulonephritis, cryoglobulinemia, neurologic disorders, psychological manifestations, polyarthritis, and dermatologic disorders. Making the diagnosis of HBV can be challenging since patients with chronic infections can remain symptom-free for decades before developing cirrhosis or hepatocellular carcinoma, and patients with acute HBV infection may have only mild, nonspecific symptoms. Therefore, understanding how this virus causes extrahepatic complications can help clinicians consider this possibility in patients with diverse symptom presentations. The pathophysiology of these extrahepatic disorders likely involves immune-related tissue injury following immune complex formation and inflammatory cascades. In some cases, direct viral infection of extrahepatic tissue may cause a clinical syndrome. Currently, the American Association for the Study of Liver Diseases recommends treatment of chronic HBV infections with interferon therapy and/or nucleos(t)ide analogs, and this treatment has been reported to improve some extrahepatic disorders in some patients with chronic HBV infection. These extrahepatic complications have a significant role in disease outcomes and increase medical costs, morbidity, and mortality. Therefore, understanding the frequency and pathogenesis of these extrahepatic complications provides important information for both specialists and nonspecialists and may help clinicians identify patients at an earlier stage of their infection.

Impact of maternal hepatitis B carrier status on congenital abnormalities: a systematic review and meta-analysis

OBJECTIVES

This study aims to explore whether maternal hepatitis B carrier status is associated with an increased risk of congenital abnormalities.

DESIGN

A systematic review and meta-analysis of observational studies.

DATA SOURCES

PubMed, Embase (Ovid), Scopus, the China National Knowledge Infrastructure (CNKI) and the Wanfang databases.

STUDY SELECTION

Five databases were searched systematically from inception to 7 September 2021. Cohort and case-control studies that investigated the association between maternal hepatitis B virus (HBV) infection and congenital abnormalities were included. This study was conducted according to MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently collected data, as well as assessed risk of bias by using Newcastle-Ottawa Scale. We pooled crude relative risk (cRR) and adjusted OR (aOR) by DerSimonian-Laird random-effects model. Heterogeneity was explored by I ² statistics, Cochran's Q test. Several subgroup analyses and sensitivity analyses were performed.

RESULTS

In total, 14 studies involving 16 205 pregnant women exposed to HBV were included. The pooled cRR of 1.15 (95% CI: 0.92 to 1.45; 14 studies included) showed a marginal but not significant association between maternal HBV-carrier status and congenital abnormalities. However, the pooled aOR of 1.40 (95% CI: 1.01 to 1.93; 8 studies included) indicated that pregnant women with HBV infection might be associated with a higher risk of congenital abnormalities. Subgroup analyses of adjusted data showed a higher pooling cRR or aOR on high prevalence HBV infection populations, as well as studies from Asia and Oceania.

CONCLUSIONS

Maternal hepatitis B carrier status might be at potential risk for congenital abnormalities. The existing evidence was not sufficient to draw a firm conclusion. Additional studies may be warranted to confirm the association.

PROSPERO REGISTRATION NUMBER

CRD42020205459.

Role of lower dose hepatitis B immune globulin prophylaxis in liver transplantation: A single center perspective

Background and Aim

Prevention of hepatitis B virus (HBV) reinfection is important for long-term outcomes following liver transplantation (LT). Hepatitis B immunoglobulin (HBIG) is used among recipients who have (i) native HBV disease, (ii) hepatitis B core antibody positivity (HBcAb positivity), or (iii) received HBcAb positive organs. Nucleos(t)ide analogue (NA) monotherapy is emerging for treating patients in this setting. There is no generalized consensus on the ideal dosage of HBIG. The aim of this study was to evaluate the efficacy of low-dose HBIG (1560 international unit [IU]) for post-LT HBV prevention.

Materials and Methods

HBcAb positive patients who received either HBcAb positive or hepatitis B core antibody negative (HBcAb negative) organs and HBcAb negative patients who received HBcAb positive organs between January 2016 and December 2020 were reviewed. Pre-LT HBV serologies were collected. HBV-prophylaxis strategy included NA with/without HBIG. HBV recurrence was defined as HBV deoxyribonucleic acid (DNA) positivity during the 1-year, post-LT follow-up. No HBV surface antibody titers were followed.

Results

A total of 103 patients with a median age of 60 years participated in the study. Hepatitis C virus was the most common etiology. Thirty-seven HBcAb negative recipients and 11 HBcAb positive recipients with undetectable HBV DNA received HBcAb positive organs and underwent prophylaxis with 4 doses of low-dose HBIG and NA. None of the recipients in our cohort had a recurrence of HBV at 1 year.

Conclusion

Low-dose HBIG (1560 IU) × 4 days and NA, for HBcAb positive recipients and HBcAb positive donors, appear to be effective in preventing HBV reinfection during the post-LT period. Further trials are needed to confirm this observation.

Cancer incidence and risk factors in dialysis patients with human immunodeficiency virus: a cohort study

Background

Patients with human immunodeficiency virus (HIV) or end-stage renal disease receiving dialysis have an increased risk of developing malignancies, but few data are available on cancer in patients with both conditions. Thus, the objective of this study was to determine the incidence of selected malignancies and identify their potential risk factors in HIV-infected dialysis patients.

Methods

This study was a nationwide cohort analysis using the US Renal Data System. Participants included all HIV-infected patients starting dialysis from 2005 to 2011. HIV status, comorbidities and malignancies were identified using International Classification of Diseases, Ninth Revision codes. Descriptive statistics and generalized linear models quantifying risk factors were performed for the overall cohort and the three most common malignancies.

Results

Overall, 6641 HIV-infected dialysis patients were identified, with 543 (8.2%) carrying a malignancy diagnosis. The most common malignancies were non-Hodgkin’s lymphoma (NHL, 25%), Kaposi sarcoma (KS, 16%) and colorectal cancer (13%). Factors increasing the risk of any malignancy diagnosis included: history of cancer [adjusted relative risk (aRR) = 5.37], two or more acquired immunodeficiency syndrome-defining opportunistic infections (ADOIs) (aRR = 3.11), one ADOI (aRR = 2.23), cirrhosis (aRR = 2.20), male sex (aRR = 1.54) and hepatitis B (aRR = 1.52). For NHL and colorectal cancer, history of cancer (aRR = 7.05 and 9.80, respectively) was the most significant risk factor. For KS, two or more ADOIs (aRR = 6.78) was the largest risk factor.

Conclusions

Over 8% of HIV-infected dialysis patients developed a malignancy. History of cancer and ADOIs were major risk factors, underscoring the significance of immune dysregulation in malignancy development.

Occult hepatitis B in kidney transplants recipients and donors from Western Mexico

BACKGROUND

Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in serum and/or liver from HBsAg-negative subjects. Our aim was to determine OBI frequency in serum and genomic DNA in patients undergoing renal transplant and their cognate donors in a selected population from Western Mexico.

METHODS

Blood samples were obtained from 94 donors and their cognate recipients (188 participants) before kidney transplantation. Identification of HBV DNA was carried-out by nested (S-region) and semi-nested (Pol-region) PCR in both genomic and serum DNA samples from 188 participants at pre-surgical stage and from a subset of 73 recipients at three-month follow-up.

RESULTS

HBV-DNA was not detected in either genomic or serum DNA samples from recipients or donors prior to transplantation. After three-months of follow-up, 2 out of 73 (2.7%, 95% CI: 0.9-11.9%) recipients were positive to HBV-DNA (Pol-region) in genomic DNA samples using a high sensitivity Taq DNA polymerase.

CONCLUSIONS

OBI incidence in recipients of kidney transplant may be higher than previously recognized. Detection of HBV-DNA was higher in genomic DNA than in serum samples using a high sensitivity Taq DNA polymerase. To the best of our knowledge, this is the first report regarding this specific topic in Mexicans.

Role of RNA secondary structure in emergence of compartment specific hepatitis B virus immune escape variants

AIM

To investigate the role of subgenotype specific RNA secondary structure in the compartment specific selection of hepatitis B virus (HBV) immune escape mutations.

METHODS

This study was based on the analysis of the specific observation of HBV subgenotype A1 in the serum/plasma, while subgenotype A2 with G145R mutation in the peripheral blood leukocytes (PBLs). Genetic variability found among the two subgenotypes was used for prediction and comparison of the full length pregenomic RNA (pgRNA) secondary structure and base pairings. RNA secondary structures were predicted for 37 °C using the Vienna RNA fold server, using default parameters. Visualization and detailed analysis was done using RNA shapes program.

RESULTS

In this analysis, using similar algorithm and conditions, entirely different pgRNA secondary structures for subgenotype A1 and subgenotype A2 were predicted, suggesting different base pairing patterns within the two subgenotypes of genotype A, specifically, in the HBV genetic region encoding the major hydrophilic loop. We observed that for subgenotype A1 specific pgRNA, nucleotide 358^U base paired with 1738^A and nucleotide 587^G base paired with 607^C. However in sharp contrast, in subgenotype A2 specific pgRNA, nucleotide 358^U was opposite to nucleotide 588^G, while 587^G was opposite to 359^U, hence precluding correct base pairing and thereby lesser stability of the stem structure. When the nucleotides at 358^U and 587^G were replaced with 358^C and 587^A respectively (as observed specifically in the PBL associated A2 sequences), these nucleotides base paired correctly with 588^G and 359^U, respectively.

CONCLUSION

The results of this study show that compartment specific mutations are associated with HBV subgenotype specific alterations in base pairing of the pgRNA, leading to compartment specific selection and preponderance of specific HBV subgenotype with unique mutational pattern.