Occult hepatitis B virus infection in hemodialysis patients: a concept for consideration

Occult Hepatitis B Infection in End-Stage Renal Disease Patients Starting Maintenance Hemodialysis at a Tertiary Care Hospital: A Descriptive Cross-sectional Study

Introduction:

Occult hepatitis B infection is defined as the presence of the hepatitis B virus deoxyribonucleic acid in liver tissues and/or serum in the absence of serum hepatitis B Virus surface antigen. The prevalence of occult hepatitis B infection in end-stage renal disease patients is largely unknown. The aim of the study is to determine the prevalence of occult hepatitis B infection in the hemodialysis population starting maintenance hemodialysis.

Methods:

A descriptive cross-sectional study was conducted in the department of Internal Medicine of a tertiary care hospital. Convenience sampling method was used; 50 consecutive end-stage renal disease patients, who started maintenance hemodialysis from March 2019 to March 2020, were enrolled in the study. The study was approved by the Institutional Review Committee of the hospital (reference number: 351/2019). Statistical Package for Social Sciences version 26.0 was used for statistical analysis.

Results:

The mean age of the patients was 50.34±12.65 years, and 42 (84%) were male. About 4 (8%) patients were diagnosed having occult hepatitis B infection, 3 (6%) of them were seropositive and 1 (2%) seronegative. About 41 (82%) patients had no history of hepatitis B vaccination series before starting hemodialysis; 36 (72%) had anti-hepatitis B surface antibody titre <10 mIU/ml. About 44 (88%) patients received a blood transfusion during their hemodialysis sessions and 14 (28%) patients had a history of receiving hemodialysis at other centres.

Conclusions:

Our study demonstrated a high prevalence of occult hepatitis B infection among end-stage renal disease patients starting hemodialysis.

Prevalence of overt and occult hepatitis B virus infections among 135 haemodialysis patients attending a haemodialysis centre at Al-Nasiriyah city, Iraq

Background and Objectives:

The prevalence of Hepatitis B virus (HBV) infection among haemodialysis (HD) patients has been well documented. In addition to overt infection, occult Hepatitis B infection exists in which a patient who is diagnosed seronegative for Hepatitis B surface antigen (HBsAg) shows positive HBV-DNA on using more accurate molecular methods. This study aims to determine the prevalence of overt and occult HBV infection among the HD patients who had attended Al-Nasiriyah dialysis centre during a two-month period.

Materials and Methods:

Serological qualitative detection of HBsAg by rapid test (strips), enzyme immunoassay (EIA, HBsAg) and molecular (real-time polymerase chain reaction (real-time PCR)) was conducted for quantitative detection of HBV in HD patients’ serum.

Results:

The prevalence of overt HBV infection among HD patients was 3.7%. The viral load of HBV positive patients was ranging from 5.85 × 10¹ to 2.16 × 10⁶ copies/ml of serum with median (7.4 × 10⁵ copies/ml). Occult Hepatitis B was not detected in any of the seronegative HD patients (0%). Overt infection was found more in males (80%) than females (20%) (P<0.05). Similarly, infection was found to be higher among patients who had blood transfusions (80%) than those who had not (20%) with statistical significant p<0.05. Although not statistically significant, the mean duration of HD was higher among HBV positive HD patients (17.6) than HBV negative HD patients (14.3). A dual infection of HBV and HCV was not detected in this study.

Conclusion:

Nosocomial transmissions at HD centres and blood transfusion are important risk factors. Besides serological screening, real-time PCR offers a safeguard against the spread of overt and occult HBV infection and determines the viral load of the positive patients.

Occult Hepatitis B Virus Infection Prevalence Among Different Populations of Iran: A Systematic Review and Meta-Analysis

Context: Various frequency rates of occult hepatitis B virus infection (OBI) are reported from different parts of Iran. This systematic review and meta-analysis aimed to characterize the OBI epidemiology in Iran and estimate the pooled prevalence among different populations. Evidence Acquisition: Nine international and Persian electronic databases, as well as some conference proceedings, were searched. Original cross-sectional studies up to December 2018 were included if they investigated the prevalence of OBI by the detection of serum hepatitis B virus surface antigen and hepatitis B virus nucleic acid in at least 30 samples selected with any sampling methods. Comprehensive meta-analysis software was used to analyze the data, and Cochran’s Q-test and I-square statistics were applied to assess the heterogeneity. Meta-regression analysis was performed to assess the impact of the year of study on the OBI frequency. A P value < 0.05 was considered as the level of significance. Results: Of 412 citations found in electronic sources and 35 relevant citations added by searching the gray literature, 83 non-duplicated non-overlapping studies were evaluated. A total of 55 documents comprising 14,485 individuals from 16 provinces met the inclusion criteria and were used in the analysis. The prevalence of OBI considerably varied in different parts of the country with the highest prevalence (63.1%) reported among the HIV-positive population in Fars province. The rates of the OBI prevalence were estimated at 0.06% (95% CI: 0.02 - 0.16%) among blood donors (BDs) regardless of their anti-HBc status, 7.90% (95% CI: 4.33 - 13.99%) among anti-HBc positive BDs, 2.49% (95% CI: 1.2 - 4.81%) among hemodialysis (HD) patients, 4.44% (95% CI: 1.56 - 12.02%) among HIV-positive patients, and 7.76% (95% CI: 4.57 - 12.86%) among HCV-positive patients. No significant trends were observed in OBI prevalence rates among different groups over time (P > 0.05). Conclusions: This review revealed high rates of OBI prevalence among high-risk populations in Iran. It is strongly suggested that occult hepatitis B be investigated among populations with a high chance of its occurrence in our country.

Prevalence of Occult Hepatitis B Virus Infection in Hemodialysis Patients Using Nested PCR

BACKGROUND

Occult hepatitis B infection (OBI) is defined as the lack of detectable HBsAg in serum, despite the presence of intrahepatic viral DNA, and low levels of covalently closed circular DNA (cccDNA). Since the hemodialysis patients are at a greater disadvantage if they are a carrier of Hep B, as it can lead to OBI this study was designed to determine the prevalence of OBI in hemodialysis patients residing in Zanjan, Iran.

METHODS

We conducted an anti-HBc test (ELISA) on 166 HBsAg negative hemodialysis patient samples. OBI was evaluated using seropositive (anti-HBc and/or anti-HBs) and seronegative (anti-HBc and anti-HBs) using nested PCR.

RESULTS

Out of the total hemodialysis patients sampled, the study consisted of 58.4% male and 41.6% female participants. The age of the study group ranged from 58.89±15.49, and had received approximately 28.27±27.43 years of dialysis. Additionally, 5.4% of patients had a history of blood transfusions, while 58.4% were vaccinated against the hepatitis B virus (HBV). Moreover, 23.5% patients were anti-HBc positive, while 76.5% patients tested negative. Lastly, 66.3% of the patients were positive for anti-HBs, whereas 33.7% were negative for anti-HBs. Overall, the study revealed that the prevalence of OBI was 6%, and HBV DNA was detected in 2.1% of individuals who were vaccinated against hepatitis B (p < 0.01).

CONCLUSION

Though no significant difference between the prevalence of OBI to the patients' age, sex, duration of dialysis, or history of blood transfusion was identified, however, a strong correlation between the prevalence of OBI to HBV vaccination was found.

Current hepatitis B virus infection situation in Indonesia and its genetic diversity

Indonesia has a moderate to high endemicity of hepatitis B virus (HBV) infection. The risk for chronic HBV infection is highest among those infected during infancy. Since 1997, hepatitis B (HepB) vaccination of newborns has been fully integrated into the National Immunization Program. Although HBV infection has been reduced by the universal newborn HepB immunization program, it continues to occur in Indonesia. The low birth dose coverage and the presence of vaccine escape mutants might contribute to this endemicity among children. Although limited information is available for an analysis of occult HBV infection (OBI), several variations and substitutions in the pre-S/S region have been detected in Indonesian HBV strains. Additionally, persistent infection and disease progression of chronic hepatitis B are related to not only viral factors but also the host genome. Indonesia is one of the most ethnically heterogeneous nations, with Javanese and Sundanese as the two highest ethnic groups. This multi-ethnicity makes genomic research in Indonesia difficult. In this article, we focused on and reviewed the following aspects: the current hepatitis B immunization program and its efficacy, OBI, HBV infection among high-risk patients, such as hemodialysis patients, and research regarding the host genome in Indonesia.

Molecular Characterization of Pre-Core/Core and S Region of Hepatitis B Virus in Hemodialysis Patients With Occult Hepatitis B Infection

BACKGROUND

Occult hepatitis B infection (OBI) is a major public health problem worldwide, which harbors potential risk of hepatitis B virus (HBV) transmission through blood transfusion and transplantation. OBI is characterized by the presence of HBV-DNA in the blood or liver tissue without detectable hepatitis B surface antigen (HBsAg) in the serum. An important cause of OBI is the occurrence of mutations in the HBV genome, especially in the S region.

OBJECTIVES

The study aims to analyze mutations in S and pre-core/core regions of HBV-DNA in hemodialysis patients.

PATIENTS AND METHODS

Sera of 216 hemodialysis patients were tested for HBsAg and hepatitis B core antibody (HBcAb) by ELISA. Sera of patients that tested negative for HBsAg were evaluated by PCR for the detection of HBV-DNA in the S and pre-core/core regions. In total, six PCR products were sequenced, aligned, and compared with the HBV reference sequence. Amino acid deletion and nucleotide substitution were considered mutations in S and pre-core/core regions of HBV-DNA.

RESULTS

Among 216 patients, 203 (93.98%) and 175 (81.01%) sera samples tested negative for HBsAg and HBcAb, respectively. Among all HBsAg-negative samples, six (2.9%) tested positive for HBV-DNA, including four (1.97%) for S and two (0.98%) for pre-core regions. All four (1.97%) samples that tested positive for the S region belonged to HBV-subtype awy. The amino acid sequence of all four samples showed the YMDD motif in position 204 (rtM204). There were three amino acid substitutions in the S region (T127P, P153L, and F170S) and one substitution in the RT region (Y135S). Moreover, two (0.98%) pre-core/core positive patients had an unexpected stop codon in position 1896.

CONCLUSIONS

This study indicates that 2.9% of hemodialysis patients had OBI, which is considered as a major public health problem worldwide. Moreover, we observed three mutations in S region, including T127P, P153L, and F170S, which caused OBI. This study is first to report a mutation analysis of HBV in hemodialysis patients in southwestern Iran. These results indicate that current screening tests based on HBsAg detection are not reliable for detection of HBV infection in dialysis patients.

Isolated anti-hbc and occult HBV infection in dialysis patients

Background:

Occult Hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV-DNA in the liver or serum with undetectable hepatitis B surface antigen (HBsAg). Hemodialysis (HD) patients are at risk of acquiring parenterally transmitted infections.

Objectives:

The aim of this study was to assess the prevalence of OBI in HD patients.

Patients and Methods:

A hundred HBsAg negative HD patients were included in this study from main dialysis units in Tehran, Iran. HBsAg, hepatitis B surface antibody (anti-HBs), hepatitis B core antibody (anti-HBc) and liver enzymes levels were examined in all subjects. The presence of HBV-DNA was determined in plasma samples using real-time PCR.

Results:

A hundredpatients with a mean age of 58.5 ± 16.1 years were enrolled in this study. In total, 56.7% were male and 43.3% female. Anti-HBs, anti-HBc, anti-HCV and anti-HIV were detected in 56.7%, 2%, 5.2% and 1% of patients, respectively. Isolated anti-HBc was detected in 2% of cases. HBV-DNA was detected in 1% of HBsAg negative patients.

Conclusions:

This study showed a low rate of isolated anti-HBc and occult HBV infection in HD patients. It can be due to improvement of people’s knowledge about HBV transmission routes, HBV vaccination of HD patients and regular surveillance of HBV infection.

Improving hepatitis B vaccine efficacy in end-stage renal diseases patients and role of adjuvants

Hepatitis B virus (HBV) infection is a serious global health problem.The prevalence of viral hepatitis is higher in dialysis patients than in the general population because of the opportunity for exposure during the dialysis procedure. Immunization is the most effective way to prevent transmission of hepatitis B virus (HBV) and hence the development of acute or chronic hepatitis B. It is well established that patients with end-stage renal disease including dialysis-dependent patients, have an impaired immune response to hepatitis B vaccine. End stage renal diseases (ESRD) patients have lower seroconversion rates compared with the subjects with intact renal function. Moreover, even after the completion of vaccination schedule anti-hepatitis B (anti-HBs) titers of responder dialysis, patients are low and decline logarithmically with time. The impaired efficacy of HBV vaccine in patients with ESRD has been attributed to numerous factors such as immune compromise because of uremia and some other factors. One approach to improve the immunogenicity of existing HBV vaccines is adjuvantation, and it's very important to find more effective adjutants for improving HBV vaccine efficacy. In this paper we have a brief review on recently known new ways for improving HBV vaccine efficacy.