Occult hepatitis B virus infection in patients with chronic liver disease of different etiology in a Brazilian referral center: comparison of two different hepatitis B virus deoxyribonucleic acid amplification protocols: a cross-sectional study

ABSTRACT BACKGROUND: Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) deoxyribonucleic acid (DNA) in the liver of individuals with undetectable hepatitis B virus surface antigen (HBsAg) in the serum. The actual prevalence of OBI and its clinical relevance are not yet fully understood. OBJECTIVE: To evaluate the prevalence of HBV DNA in liver biopsies of HBsAg-negative patients with chronic liver disease of different etiologies in a referral center in Brazil and compare two different HBV DNA amplification protocols to detect HBV. DESIGN AND SETTING: This cross-sectional observational study was conducted at the Liver Outpatient Clinic, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, between January 2016 and December 2019. METHODS: HBV DNA was investigated in 104 liver biopsy samples from individuals with chronic liver disease of different etiologies, in whom HBsAg was undetectable in serum by nested-polymerase chain reaction (nested-PCR), using two different protocols. RESULTS: OBI, diagnosed by detecting HBV DNA using both protocols, was detected in 6.7% of the 104 individuals investigated. Both protocols showed a good reliability. CONCLUSION: In addition to the differences in the prevalence of HBV infection in different regions, variations in the polymerase chain reaction technique used for HBV DNA amplification may be responsible for the large variations in the prevalence of OBI identified in different studies. There is a need for better standardization of the diagnostic methods used to diagnose this entity.

HBV serologic and virus characteristics of HBsAg negative and NAT non-discriminated samples from blood donors / 中国输血杂志

【Objective】 To investigate the HBV infection of TMA initially reactive but discriminatory test non-reactive samples(NDR) after the individual donation nucleic acid detection(ID-NAT)of TMA, and analyze its serological and molecular biological characteristics, so as to improve the safety of blood transfusion. 【Methods】 121 970 samples of blood donors in the center from January 1, 2021 to December 31, 2021 were routinely tested by serology and nucleic acid of ID NAT, and 21 HBsAg(-)/ NDR samples were random collected. After the plasma samples were concentrated by ultra-high speed centrifugation, the gene sequences of BCP/PC, pre-S/S and S region were amplified by Nested PCR. The S region sequence was also sequenced to analyze the viral genotype and amino acid variation. At the same time, the original TMA retest discriminatory test was adopted, and Roche MPX 2.0 was used for ID-NAT, and the samples was not virus-concentrated.NDR samples were supplemented with electrochemiluminescence for anti-HBc and anti-HBs quantitative detection. 【Results】 Of the 121 970 samples screened, 117(0.096%) were found to be HBsAg(-)/NDR samples, of which 21 samples underwent a confirmation test. Sixteen(76.2%) cases were positive for HBV DNA by TMA retest, 7(33.3%) positive for HBV DNA by Roche MPX 2.0 ID-NAT, 9(42.9%) confirmed by Nested PCR, and 8(38.1%) positive by any two methods. Test results of serological markers were as follows: 17(80.9%) positive anti-HBc and 8(38.1%) positive anti-HBs. Eight infected cases were confirmed to have occult hepatitis B infection(OBI). The gene sequence of S region was successfully amplified and sequenced in 3 cases, all of which belonged to C type. Two mutations occurred in specimen S-2, all of which were outside MHR. There were 13 mutations in sample S-6, 6 mutations outside MHR and 7 mutations inside MHR. 【Conclusion】 Nearly 40% of NDR samples can still be detected as HBV DNA positive after virus concentration. Anti-HBc has a high detection rate, and there may be a potential risk of HBV transmission. The current NAT detection sensitivity should be improved. The amino acid mutation of S gene sequence may be related to OBI formation.

Hepatitis B: Prevalence and occult infection in HIV-infected patients

Abstract INTRODUCTION: HBV and HIV have identical transmission routes. The aim of this study was to determine the prevalence of HBV in HIV patients and to detect the presence of occult HBV infection. METHODS: All samples were tested for serology markers and using qPCR. RESULTS: This study included 232 individuals, out of which 36.6% presented with HBV markers and 11.8% presented with HBsAg or HBV-DNA, including 3 patients that showed OBI. CONCLUSIONS: We observed a high prevalence of HBV among HIV patients. In addition, the results suggest that OBI can occur in patients with serological profiles that are indicative of past infection. Therefore, the application of molecular tests may enable the identification of infections that are not evident solely based on serology.

The prevalence of occult hepatitis B infection among the blood donors in a tertiary care hospital, Puducherry

Occult hepatitis B infection (OBI) is a cause of concern while screening the blood donors to prevent transfusion-related transmission of infection. This study was conducted to assess the prevalence of OBI using total anti-HBc by ELISA and DNA detection by real time polymerase chain reaction (PCR). The samples included were negative for HBs Ag by ELISA. Out of 1102 samples tested, 156 were positive for total anti-hepatitis B core antigen and 52/156 by real-time PCR. Overall, the prevalence was found to be 4.71% (52/1102). The results indicate that nucleic acid-based testing should be an essential part of screening procedure to prevent missing of OBI.

Detection and molecular characterisation of a diagnosis escape variant associated with occult hepatitis B virus in Brazil

BACKGROUND Many studies have identified mutations in the hepatitis B surface antigen (HBsAg) as important factors limiting the ability of commercial serological assays to detect this viral antigen. However, an association between mutations in the HBsAg gene and the occurrence of occult HBV infection (OBI) in patients has not been established. OBJECTIVES To detect hepatitis B virus (HBV) DNA in patients with anti-HBc as a unique serological marker, a previously published, cost-effective TaqMan-based real-time polymerase chain reaction (PCR) test with minor groove binding probes was adapted for use in this study. The current study also aimed to investigate HBsAg mutations and genotypes of HBV in OBI at the Viral Hepatitis Ambulatory Clinic in Rio de Janeiro to determine any possible association. METHODS Intra-assay and inter-assay reproducibility were determined, and the mean coefficient of variation values obtained were 2.07 and 3.5, respectively. Probit analysis indicated that the 95% detection level was 25 IU/mL. The prevalence of OBI was investigated in 35 serum samples with an ‘anti-HBc alone’ profile from individuals who attended our clinic between 2011 and 2013. FINDINGS HBV DNA was detected in only one sample, resulting in an OBI rate of 2.9%. Nucleotide sequencing of the pre-S/S region was performed to genotype and analyse mutations within the HBsAg gene of this HBV DNA. The HBV in the OBI case was classified as sub-genotype A1, and a sequence analysis of the small S gene revealed 12 mutations in the major hydrophilic region compared to the consensus A1 sequence. Most of these mutations occurred in amino acid residues that have been reported as clinically relevant because they have been implicated in vaccine escape and/or inability to detect HBsAg by commercial serological assays. MAIN CONCLUSIONS Our study suggests the importance of specific HBsAg mutations, different from those in D, B, and C genotypes, in sub-genotype A1 HBV associated with OBI.

Mutations in C region of hepatitis B virus may contribute to occult hepatitis B virus infection / 实用医学杂志

Objective To investigate the role of mutations in C region that may contribute to occult hepatitis B virus infection.Methods C genes were amplified from two OBI blood donor samples respectively.Plasmids with mutations in C region of hepatitis B virus were constructed by overlapping PCR.HBsAg and HBeAg in Huh7 cells and in the serum of Balb/c mice were detected by CMLA.HBcAg in liver tissue was detected by immunohistochemistry,while HBV-RNA was tested by RT-PCR.Results Mutations in C region significantly reduced the expression level of HBeAg and HBcAg,but had no significant effect on HBsAg and HBV-RNA.Conclusion The mutations in C region affect the expression level of HBeAg and HBcAg,which may play an important role in the occurrence of OBI.

High prevalence of occult hepatitis B virus genotype H infection among children with clinical hepatitis in west Mexico

Studies on the prevalence of infection with hepatitis B virus (HBV) among children are scarce in Latin American countries, especially in Mexico. This study was aimed to investigate the prevalence of HBV infection, occult hepatitis B infection (OBI) and HBV genotypes among children with clinical hepatitis. In total, 215 children with clinical hepatitis were evaluated for HBV infection. HBV serological markers and HBV DNA were analysed. OBI diagnosis and HBV genotyping was performed. HBV infection was found in 11.2% of children with clinical hepatitis. Among these HBV DNA positive-infected children, OBI was identified in 87.5% (n = 21/24) of the cases and 12.5% (n = 3/24) were positive for both HBV DNA and hepatitis B surface antigen. OBI was more frequent among children who had not been vaccinated against hepatitis B (p < 0.05) than in those who had been vaccinated. HBV genotype H was prevalent in 71% of the children followed by genotype G (8%) and genotype A (4%). In conclusion, OBI is common among Mexican children with clinical hepatitis and is associated with HBV genotype H. The results show the importance of the molecular diagnosis of HBV infection in Mexican paediatric patients with clinical hepatitis and emphasise the necessity of reinforcing hepatitis B vaccination in children.

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.

Prevalence of hepatitis B & hepatitis C virus infections in potential blood donors in rural Vietnam.

Background & objectives: Safe blood and blood products should be offered to all patients in need for blood transfusion. The objectives of the present study were to establish prevalence estimates for hepatitis B and hepatitis C virus infections as a foundation for safe blood transfusion in rural Vietnam, and to check the accuracy of the laboratory analysis used for hepatitis testing of blood donors in Vietnam. Methods: A cross-sectional study was conducted in two rural communities in Quang Tri, Vietnam. A total of 1,200 blood samples collected from potential blood donors were tested by an enzyme immunoassay technique (EIA) for detection of hepatitis surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc), and antibodies to hepatitis C antigen (anti-HCV). The EIA test outcome was validated by a chemiluminescent micro particle immunoassay technique (CMIA). Results: The prevalence of HBsAg and anti-HBc in the study population was 11.4 per cent (95% CI 9.6 - 13.2) and 51.7 per cent (95% CI 48.8 - 54.5), respectively, the prevalences being higher in males than females. The prevalence of anti-HCV was 0.17 per cent. The test agreement between the EIA and CMIA techniques was high both for HBsAg detection (κ = 0.91; 95% CI: 0.83 - 0.99) and for anti-HBc detection (κ = 0.89; 95% CI 0.81 - 0.97). Compared to CMIA results, the positive and negative predictive values of the EIA tests were found to be 94.9 per cent (95% CI 87.5 - 98.6) and 97.5 per cent (95% CI 86.8 - 99.9) for HBsAg, and 92.4 per cent (95% CI 84.2 - 97.2) and 100 per cent (95% CI 91.2 - 100) for anti-HBc. Interpretation & conclusions: The study shows that hepatitis B virus infection is endemic in rural areas of Vietnam and that almost half of the population is or has been infected. Hepatitis C infection is rare, but false negative test results cannot be ruled out. Also, the results indicate that the EIA performance in blood donor screening in Vietnam may be sub-optimal, missing 2.5 per cent of hepatitis B virus carriers and falsely excluding more than 7 per cent of blood donors. As the prevalence of hepatitis B infection is high, occult hepatitis B infection may represent a threat to safe blood transfusion. Therefore, nucleic acid amplification testing for HBV should be considered for blood donor screening in Vietnam.

Multiple cytokine expression profiles reveal immune-based differences in occult hepatitis B genotype H-infected Mexican Nahua patients

A high prevalence of occult hepatitis B (OHB) genotype H infections has been observed in the native Mexican Nahua population. In addition, a low incidence of hepatitis B virus (HBV)-associated hepatocellular carcinoma has been described in Mexico. The immune response to infection among OHB-infected patients has been poorly evaluated in vivo. Therefore, we assessed the expression profiles of 23 cytokines in OHB genotype H-infected Nahua patients. A total of 41 sera samples from natives of the Nahua community were retrospectively analysed. Based on their HBV antibody profiles, patients were stratified into two groups: OHB patients (n = 21) and patients that had recovered from HBV infection (n = 20). Herein, we report distinctive cytokines profiles in OHB-infected individuals. Compared to healthy controls (n = 20) and patients who resolved HBV infection, OHB-infected patients displayed an increase in interleukin (IL)-2 secretion in addition to a characteristic inflammation profile (decrease in IL-8 and tumour necrosis factor-alpha levels and increased levels of tumour growth factor-beta). IL-15 and interferon-gamma levels were reduced in OHB-infected individuals when compared to those patients who resolved HBV infection. In contrast, OHB patients showed an increase in monocyte chemoattractant protein (MCP)-1 and MCP-2 compared to healthy controls and patients who resolved HBV infection. These findings suggest that cytokine expression can influence the severity of OHB disease and could lead to new investigation into the treatment of liver and other infectious diseases.

Identificación de infección oculta por Virus de Hepatitis B en pacientes con insuficiencia renal crónica en Hemodiálisis en Unidad Renal del Hospital Militar Central Bogota Colombia Noviembre 2008

La infección oculta por virus de hepatitis B es una forma reconocida de infección que ha ganado interés en la última década, por su significado clínico y las implicaciones frente a los crecientes estados de inmunosupresión. La hepatitis B oculta corresponde a un estado de infección que no presenta marcadores serológicos como antígeno de superficie de hepatitis b, o elevación de transaminasas; su diagnostico se basa en la presencia de DNA viral en población con o sin anticuerpos contra la partícula del core viral, siendo la población de mayor riesgo, los pacientes con trasplante hepático receptores de donante core +, pacientes con hepatocarcinoma, pacientes con cirrosis criptogénica pacientes con insuficiencia renal crónica, usuarios de drogas intravenosas y donantes de sangre frecuentes. Objetivo: Identificar pacientes con infección oculta por virus de hepatitis B en población con insuficiencia renal crónica en hemodiálisis con mayor riesgo, dados por la presencia de anticuerpo contra partícula core VHB y coinfección con virus de hepatitis C. Materiales y métodos: Pacientes con insuficiencia renal crónica en hemodiálisis en la unidad renal del hospital Militar central. Se describen las características demográficas básicas y se identifican los pacientes con anticuerpo core positivo de manera exclusiva, e infección por virus de hepatitis C. Teniendo en cuenta que esta es la población de mayor riesgo de infección oculta, se realiza cuantificacion del genoma viral por técnica de amplificación. Resultados: La serie corresponde a una población adulta mayor predominantemente masculina, con insuficiencia renal crónica secundaria a nefropatía diabética e hipertensiva en su mayoría; el 54 % de los pacientes vacunados contra hepatitis B presenta anticuerpos protectores, y el 13 % presenta anticuerpo contra partícula core del virus de hepatitis B como marcador exclusivo de enfermedad y un paciente con infección por virus de hepatitis C, sin encontrar la presencia de genoma viral en estos pacientes. Discusión: Los pacientes con insuficiencia renal crónica en hemodiálisis que están expuestos a hemoderivados y procedimientos invasivos; a pesar de las normas de bioseguridad, se encuentran en alto riesgo de infección oculta por virus de hepatitis B. Los estudios multinaciones realizados a nivel mundial muestran una gran variabiliadad en la prevalencia de Hepatitis B oculta, a razón de las características demográficas propias de las poblaciones estudiadas. Conclusiones: No se encontró genoma viral de virus de hepatitis B en pacientes con insuficiencia renal crónica en hemodiálisis mayor de seis meses con anticuerpo contra partícula core positivo exclusivo y coinfección con virus de hepatitis C en la unidad renal del hospital Militar central a noviembre de 2008.

Occult Hepatitis B infection is a very well known form of infection, which has gained attention during the last decade because of its clinical significance and the implications facing immunosuppression conditions. Occult hepatitis B corresponds to an infectious state with the absence of serological hepatitis B markers or transaminase elevation. Its diagnostic is based on viral DNA presence in people who may have or not antibodies against viral coreÊs particle, being the most risky population patients who have had hepatic transplant, receivers of positive core donor, patients with hepatocellular carcinoma, patients with cryptogenic cirrhosis, patients with chronic kidney failure, intravenous drug users and frequent blood donors. This studyÊs objective was to identify patients with occult hepatitis B infection in a population with chronic kidney failure on hemodialysis with higher risk given by the presence of the core particle antibody and co-infection with hepatitis C virus. Materials and methods: the current study takes as target a population of patients with chronic kidney failure in hemodialysis at the kidney unit of the "Hospital Militar Central". A survey which pretends to describe the basic demographic characteristics and to identify patients with exclusive positive core antibody and hepatitis C is applied taking into account that this population is at the highest risk for hidden infection; viral genome identification by the amplification technique was done. Results: the series correspond to a basically adult male population with secondary chronic kidney failure due to diabetic and hypertensive nephropathy; 54% of vaccined patients against hepatitis B had protective antibodies and, 13% presented antibodies against core particle of hepatitis B virus, and one patient was positive to Hepatitis C virus, without the presence of viral genome in this population. Discussion: patients with chronic kidney failure on hemodialysis who are exposed to blood derivatives and invasive procedures in spite of bio - safety policies are at high risk for occult hepatitis B infection. Multinational studies conducted worldwide, show a wide geographical variability in occult hepatitis B prevalence. Conclusions: No hepatitis B viral genome was detected in patients with chronic kidney failure on hemodialysis treatment longer than six months with antibody against core particle and co-infection with hepatitis C virus in the kidney unit of "Hospital Militar Central" by November 2008.