Occult hepatitis B among patients with chronic renal failure on hemodialysis from a capital city in northeast Brazil

Prevalence of occult hepatitis B virus infection among patients receiving haemodialysis in Sana'a city

BACKGROUND

Occult hepatitis B virus infection (OBI) is a challenging entity. Due to the increase in invasive procedures, blood transfusions, and difficulties in diagnosing OBI, patients are more likely to acquire OBI. This cross-sectional study was conducted to assess the prevalence of OBI by hepatitis B virus (HBV)-DNA detection, the prevalence of HBV infection by total hepatitis B core antibody (HBcAb) detection, and the potential risk factors for HBV infection in patients receiving haemodialysis regularly.

METHODS

This study included 80 patients receiving haemodialysis regularly, without acute or chronic HBV infection. They were selected from the dialysis units in Sana'a city, Yemen from June 2016 to June 2017. Patients who were positive for hepatitis B surface antigen and hepatitis B surface antibody were excluded from this study. Blood samples were taken prior to each haemodialysis session, and serological markers of HBV were included. HBcAb was measured by enzyme-linked immunosorbent assay, and HBV-DNA was measured by polymerase chain reaction.

RESULTS

HBV-DNA was detected in four patients (5%) and HBcAb was detected in 38 patients (47.5%). There was a significant association between HBV-DNA and HBcAb in patients receiving haemodialysis regularly.

CONCLUSIONS

Patients who test positive for HBcAb should undergo additional HBV-DNA testing to allow accurate HBV screening and prevent infection of other patients.

Prevalence of hepatitis C virus infection in patients with end-stage renal disease in Latin America and the Caribbean: a systematic review and meta-analysis

AIM

To estimate the prevalence of hepatitis C virus (HCV) infection in patients with end-stage renal disease (ESRD) undergoing hemodialysis in Latin America and the Caribbean (LAC).

MATERIALS AND METHODS

Observational studies published in Spanish, Portuguese, and English language by November 25, 2021, in PubMed, Embase, Web of Science, Scopus, SciELO, and LILACS were selected by two reviewers according to predefined eligibility criteria. Study quality was assessed using the US National Heart, Lung and Blood Institute tool for observational cohort and cross-sectional studies. A meta-analysis of proportions was performed using a random-effects model based on the DerSimonian and Laird method, using R. PROSPERO N°: CRD42018107403.

RESULTS

A total of 20 studies were included in the narrative synthesis (15 from Brazil, two from Cuba, two from Argentina, and one from Peru). Only 17 studies were included in the meta-analysis (13 from Brazil, two from Argentina, one from Cuba, and one from Peru). The overall prevalence of HCV in ESRD patients undergoing hemodialysis in LAC was 11.3% (95% confidence interval [CI]: 8.9% - 13.9%; I²: 99 %). In Brazil and Argentina, the prevalence was 6% and 26.1%, respectively. Prevalence after excluding poor-quality studies was 10.7%.

CONCLUSION

The prevalence of HCV in ESRD patients undergoing hemodialysis in LAC was 11.3%. The implementation of infection control measures in hemodialysis centers in LAC is required. It is also necessary to increase the number of studies on the subject in the ESRD population in most LAC countries.

Occult Hepatitis B Infection among Hemodialysis in Tabriz, Northwest of Iran: Prevalence and Mutations within the S Region

Regardless of the extensive screening for the detection of hepatitis B surface antigen (HBsAg), hemodialysis (HD) patients are still severely at the risk of occult hepatitis B virus infection (OBI), especially in developing countries. OBI is defined as the presence of HBV DNA with undetectable HBsAg in the liver and/or Serum. This study aims to determine the prevalence of OBI in HD patients in Tabriz Province, northwest of Iran, and inquire about the mutations in the detected HBsAg. In this cross-sectional descriptive study, ELISA method assessed serum and plasma samples of 118 HBsAg-negative patients undergoing HD treatment for HBV serological markers (HBsAg and Anti-HBc). Specific primers by nested polymerase chain reaction have been utilized to examine HBV DNA; also, direct sequencing of surface genes was carried out to characterize the viral genotypes and S gene mutations. Finally, followed by real-time PCR, the quantity of viral load in OBI-positive patients was determined. A total of 118 HD patients were included (63.6% were male and 36.4% female), with an overall mean age of 60.8 ± 12.8 years old. The prevalence of antihepatitis B core antibody (Anti-HBc) in the study population was 26.3% (31/118). Five patients (4.2%) were positive for HBV DNA and labeled OBI-positive; their plasma HBV-DNA load was less than 100 IU/ml. Following the phylogenetic analysis, the samples with OBI roughly belonged to genotype D, subtype ayw2 and only two had mutations within the S ’gene’s major hydrophilic region (MHR), including T123I, C124F, and P127T. This study reports the prevalence of OBI in the HBsAg-negative HD patients being at a rate of 4.2%, which can be a clinically vital consideration in this region. HBV serologic screening approaches need to be renewed to cover nucleic acid testing in the setting of hemodialysis and all the other high-risk groups associated with it (i.e., blood and organ donors).

Hepatitis B Virus Infection among Japanese Immigrants and Descendants: The Need to Strengthen Preventive and Control Measures

This cross-sectional study aimed to investigate the prevalence and risk factors of Hepatitis B virus infection among Japanese immigrants and their descendants from São Paulo (SP), and to verify the occurrence of occult hepatitis B and coinfection with HCV, Delta, and HTLV. All samples (n = 2.127) were tested for HBV serological markers by electrochemiluminescence. HBsAg and/or total anti-HBc positive samples were tested for HBV DNA by real-time PCR, and genotyped by sequencing using the Sanger methodology. The prevalence rate of HBV exposure was 13.4% (CI 95%: 11.9–14.9%), and 22 (1.1%) were HBsAg positive. A high rate of susceptibility to HBV infection was found (67.4%; CI 95%: 65.4–69.4%). In contrast, only 19.2% (CI 95%: 17.6–20.9%) presented a serological profile analogous to that elicited by Hepatitis B vaccination. HBV isolates (n = 8) were classified as genotypes HBV/B1 (62.5%), HBV/C2 (12.5%), HBV/F1b (12.5%), and HBV/A1 (12.5%). Hepatitis B vaccination strategies and educational measures to control this infection should be considered.

Molecular investigation of occult hepatitis B virus infection in a reference center in Northern Brazil

The goal of this study was to investigate the prevalence of occult HBV infection in a reference center for the Northern Brazil from 2005 to 2015 and to identify mutations associated with occult hepatitis B. Molecular analysis was performed on 110 serum samples in which anti-HBc was the only positive serological marker. Regions of the HBV genome were amplified by polymerase chain reaction to detect HBV DNA. A prevalence of 4.1% (793/18,889) for anti-HBc alone was identified. Molecular analysis revealed a prevalence of occult HBV infection of 0.04%. HBV DNA detected were identified in individuals who underwent hemodialysis, infected with the hepatitis C virus and from area of high endemicity for HBV. Direct DNA nucleotide sequencing and phylogenetic analysis identified that genotypes A and D and mutations E164D, I195M, P217L and P120S were associated with occult HBV infection in the S gene. This study contributed with epidemiological and molecular information on Northern Brazil samples with a suggestive profile of occult HBV infection in addition to reinforcing the importance of molecular diagnosis in this type of infection.

Persistently high hepatitis C rates in haemodialysis patients in Brazil [a systematic review and meta-analysis]

We conducted a systematic review and meta-analysis of studies assessing HCV infection rates in haemodialysis patients in Brazil (Prospero CRD #42021275068). We included studies on patients under haemodialysis, comprising both convenience samples and exhaustive information from selected services. Patients underwent HCV serological testing with or without confirmation by HCV RNA PCR. Exclusion criteria were the following: absence of primary empirical information and studies without information on their respective settings, study year, accurate infection rates, or full specification of diagnostic tests. Studies with samples ≤ 30 and serial assessments with repeated information were also excluded. Reference databases included PubMed, LILACS, Scopus, and Web of Science for the period 1989–2019. A systematic review was carried out, followed by two independent meta-analyses: (i) studies with data on HCV prevalence and (ii) studies with a confirmatory PCR (i.e., active infection), respectively. A comprehensive set of different methods and procedures were used: forest plots and respective statistics, polynomial regression, meta-regression, subgroup influence, quality assessment, and trim-and-fill analysis. 29 studies and 11,290 individuals were assessed. The average time patients were in haemodialysis varied from 23.5 to 56.3 months. Prevalence of HCV infection was highly heterogeneous, with a pronounced decrease from 1992 to 2001, followed by a plateau and a slight decrease in recent years. The summary measure for HCV prevalence was 34% (95% CI 26–43%) for studies implemented before 2001. For studies implemented after 2001, the corresponding summary measure was 11% (95% CI 8–15%). Estimates for prevalence of active HCV infection were also highly heterogeneous. There was a marked decline from 1996 to 2001, followed by a plateau and a slight increase after 2010. The summary measure for active HCV infection was 19% (95% CI 15–25%) in studies carried out before 2001. For studies implemented after 2001, the corresponding summary measure was 9% (95% CI 6–13%). Heterogeneity was pervasive, but different analyses helped to identify its underlying sources. Besides the year each study was conducted, the findings differed markedly between geographic regions and were heavily influenced by the size of the studies and publication biases. Our systematic review and meta-analysis documented a substantial decline in HCV prevalence among Brazilian haemodialysis patients from 1992 to 2015. CKD should be targeted with specific interventions to prevent HCV infection, and if prevention fails, prompt diagnosis and treatment. Although the goal of HCV elimination by 2030 in Brazil remains elusive, it is necessary to adopt measures to achieve micro-elimination and to launch initiatives towards targeted interventions to curb the spread of HCV in people with CKD, among other high-risk groups. This is of particular concern in the context of a protracted COVID-19 pandemic and a major economic and political crisis.

Cytokine profile during occult hepatitis B virus infection in chronic hepatitis C patients

Background

The hepatitis B virus (HBV) is one of the leading causes of acute, chronic and occult hepatitis (OBI) representing a serious public health threat. Cytokines are known to be important chemical mediators that regulate the differentiation, proliferation and function of immune cells. Accumulating evidence indicate that the inadequate immune responses are responsible for HBV persistency. The aim of this study were to investigate the cytokines IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-10 and IL-17A in patients with OBI and verify if there is an association between the levels of these cytokines with the determination of clinical courses during HBV occult infection.

Methods

114 patients with chronic hepatitis C were investigated through serological and molecular tests, the OBI coinfected patients were subjected to the test for cytokines using the commercial human CBA kit. As controls, ten healthy donors with no history of liver disease and 10 chronic HBV monoinfected patients of similar age to OBI patients were selected.

Results

Among 114 HCV patients investigated, 11 individuals had occult hepatitis B. The levels of cytokines were heterogeneous between the groups, most of the cytokines showed higher levels of production detection among OBI/HCV individuals when compared to control group and HBV monoinfected pacients. We found a high level of IL-17A in the HBV monoinfected group, high levels of TNF-α, IL-10, IL-6, IL-4 and IL-2 in OBI/HCV patients.

Conclusion

These cytokines could be involved in the persistence of HBV DNA in hepatocytes triggers a constant immune response, inducing continuous liver inflammation, which can accelerate liver damage and favor the development of liver cirrhosis in other chronic liver diseases.

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.

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.

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.

Prevalence of occult hepatitis B in a population from the Brazilian Amazon region

In the present study, we evaluated the prevalence of occult hepatitis B (OBI) in a population from the Brazilian Amazon region, identify circulating genotypes, and mutations in the S gene. One hundred eighty-one patients with negative serology for HBsAg and anti-HBs and positive serology for anti-HBc participated in the study. Detection of viral DNA, genotyping by sequencing, and analysis of nucleotide sequences to detect possible mutations were performed. HBV DNA was detected in 14.36% of the patients. Genotyping revealed genotype A in 88.46% of HBV DNA-positive subjects, with subgenotype A1 being the most prevalent (78.26%) followed by subgenotype A2 (21.74%). Genotype F was detected in 11.54% (all of them subgenotype F2). Amino acid substitutions were observed in the amplified S gene in individuals with OBI compared to HBsAg-positive individuals (evident infection). In conclusion, the results show a high prevalence of OBI in the population studied, with a pattern of genotypes A and F that circulate in the Brazilian Amazon region. Amino acid substitutions were detected in part of the S gene in patients with OBI. Further studies on the molecular epidemiology of HBV in this region are important to identify patients considered healthy but who are potential transmitters of the disease.

Prevalence of occult hepatitis B virus infection and Torque teno virus infection and their association with hepatocellular carcinoma in chronic hepatitis C patients

BACKGROUND

The role of occult hepatitis B virus (HBV) infection and Torque teno virus (TTV) infection in the development of hepatocellular carcinoma (HCC) in chronic hepatitis C patients is still uncertain.

AIM

The aim of the present study was to investigate the prevalence and significance of OBI and TTV infection, and to examine the genetic diversity of these viruses, in chronic hepatitis C patients with and without HCC.

METHODS

Sera from 151 hepatitis C virus (HCV)-infected patients (49 patients with HCC and 102 without HCC) negative for HBV surface antigen (HBsAg) were tested for the presence of OBI and TTV infection by semi-nested and group-specific multiplex PCR assays, respectively. Nucleotide sequencing of HBV S region was further performed.

RESULTS

OBI and TTV infection were detected in 5 (3.3%) and 68 (45%) patients, respectively. HBV isolates were classified into genotypes A (4/5, 80%) and D (1/5, 20%), and no HBsAg escape mutation was observed. TTV phylogenetic group 3 was the most prevalent among both HCC and non-HCC patients. OBI and TTV infection were significantly more frequent in patients with HCC than patients without HCC (p=0.003, and p=0.009, respectively). Moreover, TTV infection was associated with HCC (OR=2.23, 95%CI=1.04-4.80, p=0.040), independently of liver cirrhosis.

CONCLUSIONS

A low prevalence of OBI was observed in patients with HCV-related chronic liver disease, and TTV infection was an independent factor associated with the occurrence of HCC. Whether TTV influences the progression of liver disease in chronic hepatitis C patients remains to be elucidated.