Prevalence and clinical significance of occult hepatitis B virus infection among renal transplant recipients in Korea

The Use of Residual Blood Specimens in Seroprevalence Studies for Vaccine-Preventable Diseases: A Scoping Review

Background: Residual blood specimens offer a cost- and time-efficient alternative for conducting serological surveys. However, their use is often criticized due to potential issues with the representativeness of the target population and/or limited availability of associated metadata. We conducted a scoping review to examine where, when, how, and why residual blood specimens have been used in serological surveys for vaccine-preventable diseases (VPDs) and how potential selection biases are addressed. Methods: The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines and identified relevant papers published in 1990-2022. Results: A total of 601 articles met the inclusion criteria after title, abstract screening, and full-text review. The most studied VPDs using residual blood specimens were COVID-19 (27%), hepatitis E (16%), hepatitis B (10%), influenza (9%), HPV (7%), and measles (7%). Residual blood specimens were primarily sourced from diagnostic specimens (61%) or blood and plasma donations (37%). Almost all articles used specimens linked to basic demographic data (e.g., age and sex), with 47% having access to extended demographic data (e.g., geographic location). Common strategies to address potential biases included comparing results with published estimates (78%) and performing stratified analyses (71%). Conclusions: Residual blood specimens are widely used in seroprevalence studies, particularly during emerging disease outbreaks when rapid estimates are critical. However, this review highlighted inconsistencies in how researchers analyze and report the use of residual specimens. We propose a set of recommendations to improve the analysis, reporting, and ethical considerations of serological surveys using residual specimens.

Estimates of the prevalence of occult HBV infection in Asia: a systematic review and meta-analysis

PURPOSE

Occult Hepatitis B virus infection (OBI) is of great significance to the transmission of Hepatitis B virus (HBV) and the evolution of the patient's clinical outcome. We conducted a systematic review and meta-analysis to estimate the prevalence of OBI in Asia.

METHODS

Literature search was conducted in PubMed, Cochrane Library database, Web of Science and Embase with the keywords of 'Hepatitis B virus', 'occult infection', 'prevalence'. 70 studies were included in the meta-analysis. Meta-analysis was performed using random-effects models to calculate the pooled prevalence of OBI and 95% confidence interval (CI). The data were analyzed in R 4.1.2.

RESULTS

The overall prevalence of OBI was 4% (95%CI: 0.03-0.06) in Asia. Subgroup analysis based on geographic region showed a prevalence of 3% (95%CI 0.02-0.06) in East Asia, 9% (95%CI 0.05-0.15) in West Asia, 3% (95%CI 0.01-0.11) in Southern Asia and 9% (95%CI 0.05-0.15) in Southeast Asia. Subgroup analysis demonstrated a prevalence of 1% (95%CI 0.00-0.02) in general population, 5% (95%CI: 0.03-0.08) in high-risk population, 9% (95%CI: 0.03-0.22) in the human immunodeficiency virus (HIV)-infected patient, 18% (95%CI: 0.09-0.32) in the hepatopathy patients.

CONCLUSION

Based on the meta-analysis of the prevalence of OBI in different populations, we concluded that the prevalence of OBI in the high-risk population, hepatopathy patients, and HIV-infected patients was higher than that in the general population. A systematic review showed that OBI was associated with disease progression and prognosis. Therefore, these populations should be routinely screened for OBI and promptly intervened to avoid promoting disease progression.

Occult hepatitis B virus infection in Sudan: A systematic review and meta-analysis

In its occult form, hepatitis B virus infection can only be detected using molecular techniques such as polymerase chain reaction, increasing the cost of the screening process. Certain population subgroups are considered to have a higher risk of transmission and reactivation of occult hepatitis B virus infection (OBI). This review aims to estimate the prevalence of OBI among these high‐risk groups in Sudan. It was conducted under the PRISMA guidelines, targeting the literature available in MEDLINE/PubMed, ScienceDirect, Google Scholar, and Cochrane Library databases. Full‐text articles published in the last 10 years that provide prevalence estimates of OBI in Sudan were examined for fulfillment of eligibility criteria. Quality assessment of selected articles was performed using the critical appraisal tool reported by Munn et al. Publication bias was assessed by visual examination of the funnel plot. Meta‐analysis using the random‐effects model with 95% confidence interval was used to calculate the overall and subgroup pooled prevalence of OBI. Literature search yielded a total of 717 studies, of which only 11 articles fulfilled all selection criteria. The overall pooled prevalence of OBI was found to be 15.51%, with a high level of heterogeneity. Subgroup analysis demonstrated a prevalence of 16.48% among blood donors, 13.36% among hemodialysis patients, and 12.59% among febrile patients. Evidence for possible publication bias was detected. This review provides crucial evidence for health authorities in Sudan, outlining the necessity for re‐evaluation of the current screening strategies, especially among these high‐risk groups.

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.

Presence of Hepatitis B Surface Antibody in Addition to Hepatitis B Core Antibody Confers Protection Against Hepatitis B Virus Infection in Hepatitis B Surface Antigen-negative Patients Undergoing Kidney Transplantation

BACKGROUND

The American Gastroenterological Association and European Association for the Study of the Liver recommend that hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (anti-HBc)-positive patients who receive immunosuppression should be monitored for hepatitis B virus (HBV) infection regardless of hepatitis B surface antibody (anti-HBs) status. However, anti-HBs may provide protection against infection. To investigate whether the presence of anti-HBs in addition to anti-HBc confers protection, we classified HBsAg(-) kidney transplantation (KT) patients into 4 groups according to anti-HBc and anti-HBs status, and compared the HBV infection rate between the anti-HBc(+)anti-HBs(+) group and the other 3 groups.

METHODS

In this single-center retrospective study, we classified 1959 patients into 4 groups: anti-HBc(-)anti-HBs(-) (n = 356), anti-HBc(-)anti-HBs(+) (n = 652), anti-HBc(+)anti-HBs(-) (n = 142), and anti-HBc(+)anti-HBs(+) (n = 809).

RESULTS

Hepatitis B virus infection was noted in 31 (1.6%) patients after KT. There was a significant difference in HBV infection rate between anti-HBc(+)anti-HBs(+) (1.2%) and anti-HBc(+)anti-HBs(-) (5.6%) (P < 0.001), but not between anti-HBc(+)anti-HBs(+) and anti-HBc(-)anti-HBs(-) (1.1%) or anti-HBc(-)anti-HBs(+) (1.4%). There was a significant difference in HBV infection rate according to anti-HBs titer, but no difference according to the donor viral profile. Hepatic failure occurred in 1 anti-HBc(+)anti-HBs(-) patient and 1 anti-HBc(+)anti-HBs(+) patient, both of whom died. Hepatocellular carcinoma was noted in 4 anti-HBc(-) patients, but not in anti-HBc(+) patients.

CONCLUSIONS

The presence of anti-HBs confers protection against HBV infection. We recommend monitoring for HBV infection after KT in HBsAg(-) anti-HBc(+) anti-HBs(-) patients, but not in HBsAg(-) anti-HBc(+) anti-HBs(+) patients.

Low prevalence of occult hepatitis B virus infection in chronic haemodialysis and kidney transplant patients

BACKGROUND

Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in serum and/or liver in HBsAg-negative patients. We investigated the prevalence of OBI in large chronic haemodialysis (CHD) and kidney transplant recipients (KTxR) cohorts, including determination of HBV DNA in peripheral blood mononuclear cells (PBMCs).

METHODS

HBV DNA was determined in both serum and PBMCs in 417 CHD patients, 417 KTxR, 20 HBsAg-positive non-CHD non-KTx patients (positive controls) and 40 HBsAg-negative healthy subjects (negative controls).

RESULTS

Chronic haemodialysis group: two of 376 patients were HBsAg-positive. The 374 HBsAg-negative patients tested negative for HBV DNA in both serum and PBMCs. KTxR group: 14 of 417 patients were HBsAg-positive. One of 403 HBsAg-negative patients tested positive for HBV DNA in serum but not in PBMCs. Positive controls: six of 20 patients were under antiviral therapy and had negative HBV DNA in both serum and PBMCs. In 11 of 14 remaining patients, HBV DNA was detected in serum and in both serum and PBMCs in 3 patients. Negative controls: All 34 patients were anti-HBc-negative and HBV DNA-negative in both serum and PBMCs. In the long term, the only case of anti-HBc-negative OBI lost anti-HBs 5 years after inclusion in the study and showed HBV reactivation with HBsAg re-seroconversion.

CONCLUSIONS

We found nil prevalence of OBI in CHD patients and a very low prevalence (<1%) in KTxR suggesting that routine screening for HBV DNA is not required in CHD population in our region. However, in KTxR, pretransplant screening with HBV DNA should be considered. Testing for HBV DNA in PBMCs does not seem to be of additional value.

Occult hepatitis B virus infection in HIV positive patients at a tertiary healthcare unit in eastern India

Occult HBV infection (OBI), defined by the presence of HBV DNA in absence of hepatitis B surface antigen (HBsAg), is a significant concern in the HIV-infected population. Of 441 HIV+/HBsAg- patients analyzed, the overall prevalence of OBI was 6.3% (28/441). OBI was identified in 21 anti-HBc positives (17.8%), as well as among those who lacked any HBV-specific serological markers (2.2%). Comparison with HIV/HBV co-infection revealed that the levels of CD4, ALT, and HBV DNA were significantly lower during occult infection. Discrete differences were also observed with respect to quasispecies divergence. Additionally, subgenotype D1 was most frequent in occult infection, while D2 was widespread during chronic infection. The majority (~90%) of occult D1 sequences had the sQ129R mutation in the surface gene. This study highlights several distinct features of OBI in India and underscores the need for additional HBV DNA screening in HIV-positive individuals.

Occult hepatitis B virus infection of hemodialysis patients: a cross-sectional study in a hepatitis B virus-endemic region

Occult hepatitis B virus (HBV) infection is defined as the presence of HBV DNA in the liver tissue and/or serum of subjects seronegative for hepatitis B surface antigen (HBsAg). Occult HBV infection of hemodialysis (HD) patients is informative in terms of virus transmission, reactivation after kidney transplantation, and the progression of liver disease. However, there is little detailed information about occult HBV infection in the context of virus endemicity. We tried to investigate the seroprevalence and clinical features of occult HBV infection in HD patients in HBV-endemic regions. We enrolled a total of 159 HD patients and 121 apparently healthy subjects at Dankook University Hospital and Jeju National University Hospital in Korea. HBsAg, anti-HBs, anti-HBc, and anti-hepatitis C virus (HCV) antibody levels were measured by radioimmunoassay. Serum levels of HBV DNA were measured by real-time polymerase chain reaction. The seroprevalence of occult HBV infection was 1.3% in HD patients and 2.5% in the healthy controls. This difference was not significant. The HBV load in all subjects with occult infection was <116 copies/mL, and all were positive for IgG anti-HBc, regardless of the presence of anti-HBs. None of the occult HBV-infected subjects were co-infected with HCV. One of the 2 HD patients with occult HBV infection had no history of blood transfusion. In this HBV-endemic region, the seroprevalence of occult HBV infection in HD patients with a very low viral load was not significantly different from that in apparently healthy subjects.

Prevalence of occult hepatitis B virus infection in kidney transplant recipients

In this cross-sectional study, 207 hepatitis B surface antigen (HBsAg)-negative kidney transplant recipients were evaluated based on demographic and epidemiological data and on the levels of serological markers of hepatitis B virus (HBV) and hepatitis C virus infection and liver enzymes. Patients with HBV or human immunodeficiency virus infection were excluded. Sera were analysed for the presence of HBV-DNA. HBV-DNA was detected in two patients (1%), indicating occult hepatitis B (OHB) infection (the HBV-DNA loads were 3.1 and 3.5 IU/mL in these patients). The results of the liver function tests were normal and no serological markers indicative of HBV infection were detected. The prevalence of OHB infection was low among kidney transplant recipients, most likely due to the low HBsAg endemicity in the general population of the study area.

Outcomes and risk factors for hepatitis B virus (HBV) reactivation after kidney transplantation in occult HBV carriers

PURPOSE

The purpose of this study was to explore the outcomes and risk factors for hepatitis B virus (HBV) reactivation after kidney transplantation in occult HBV carriers, who are hepatitis B surface antigen (HBsAg) seronegative and hepatitis B core antibody (HBcAb) seropositive before kidney transplantation.

METHODS

We retrospectively analyzed 322 occult HBV carriers who received kidney transplantation in our hospital from January 1998 to June 2008. HBsAg and HBV DNA were routinely checked for diagnosis of HBV reactivation.

RESULTS

Our results showed that 15 cases (4.7%) of occult HBV carriers had HBV reactivation after kidney transplantation. Kaplan-Meier analysis showed that 1-, 3-, 5-, and 10-year patient survival was 86.7%, 79.4%, 72.2%, and 65.0%, respectively, in the HBV reactivation group, and was 96.1%, 93.8%, 91.5%, and 84.5%, respectively, in the non-HBV reactivation group (log-rank 4.12, P = 0.042). Graft survival showed no difference between these 2 groups (P > 0.05). The incidences of impairment of liver function, liver function failure, hepatocellular carcinoma, and acute rejection were significantly higher in the HBV reactivation group compared with the non-HBV reactivation group (P < 0.05). Logistic multivariate analysis showed that older age (>60 years) and using anti-T-cell antibodies were independent risk factors for HBV reactivation after kidney transplantation, while being hepatitis B surface antibody (HBsAb) seropositive and using lamivudine prophylaxis could protect occult HBV carriers from HBV reactivation after kidney transplantation (P < 0.05).

CONCLUSION

In conclusion, our data showed that HBV reactivation may diminish the patient survival but not graft survival. Older age and anti-T-cell antibodies may increase the risk of HBV reactivation, whereas lamivudine prophylaxis may prevent HBV reactivation after kidney transplantation.