Exploratory analysis of HLA SNPs associated with occult HBV infection: a multicenter case-control study in Chinese blood donors.

Occult hepatitis B virus (HBV) and occult hepatitis C virus (HCV) infection are two recently described different forms of HBV and HCV infections. This work compares the clinical, virologic, and histologic characteristics of patients with occult dual infection to those of patients with single occult HBV or HCV infection. Seventy-six patients with abnormal liver function tests of unknown etiology (serum HBsAg, anti-HCV, HBV-DNA, and HCV-RNA negative) were included in the study. Viral genomes were tested in liver by real-time PCR and confirmed by in situ hybridization. Of the 76 patients, 17 had occult HBV infection (intrahepatic HBV-DNA positive, HCV-RNA negative), 35 had occult HCV infection (intrahepatic HCV-RNA positive, HBV-DNA negative) and 24 occult dual infection (intrahepatic HCV-RNA and HBV-DNA). No differences among the three groups were found regarding clinical and epidemiologic data. The median load of intrahepatic genomic and antigenomic HCV-RNA strands was similar between single occult HCV infection and occult HBV and HCV dual infection. The percentage of HCV-infected hepatocytes did not differ between these groups. In occult single HBV infection, intrahepatic levels of HBV-DNA and percentage of HBV-infected hepatocytes were similar to the group of patients with occult dual infection. Finally, no differences were found in histological liver damage among the three groups. In conclusion, liver disease in patients with occult dual infection was not more severe than in patients with single occult HBV or occult HCV infection. Moreover, in occult dual infection there is no a reciprocal inhibition of the viral genomes.

Occult hepatitis B virus infection (OBI) is a well-recognized clinical entity characterized by the detection of HBV DNA in serum and/or liver in the absence of detectable HBsAg. Diagnosis of OBI requires a sensitive HBV DNA assay. We aimed at determining the frequency of OBI in infants, born to HBsAg-positive mothers, who received immunoprophylaxis at birth. Sixty-four infants and children, born to HBsAg-positive mothers, who received hepatitis B immunoglobulin and HBV vaccine within 48 h after birth, were tested for HBV serological profile and HBV DNA by real-time PCR at least 1 month after last dose of HBV vaccine and not before 6 months of age. The median age of the studied infants and children was 8 months, ranging from 6 to 132 months; 54.7 % were females. HBV DNA was detected in 2 infants. One case had OBI; she was negative for HBsAg, anti-HBc total, HBeAg and was positive for anti-HBs (titer 267 mIU/mL) with low level of viremia (HBV DNA 1.13 x 10(3) IU/mL). Another infant showed immunoprophylaxis failure with positive HBsAg, anti-HBc total, HBeAg, negative anti-HBe and anti-HBs; HBV viral load was 1.7 × 10(8) IU/mL. Both mothers were HBsAg and HBeAg-positive. OBI may occur in infants born to HBsAg-positive mothers despite the receipt of immunoprophylaxis. OBI was detected in a low frequency in the present study. Anti-HBs positivity does not exclude OBI.

Impact of Occult Hepatitis B Virus Infection or Hepatitis B Virus DNA Integration on Efficacy of Chronic Hepatitis C Treatment With Peginterferon and Ribavirin

Occult hepatitis B virus infection (OBI) has been reported among patients with chronic hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). This study aimed to evaluate the prevalence of OBI in chronic hepatitis C patients with and without hepatocellular carcinoma. A total of 40 chronic hepatitis C patients who were negative for HBsAg, were enrolled into the study. They were classified into two groups: Group I which included 20 patients with chronic hepatitis C only whereas Group II included 20 patients with chronic hepatitis C and HCC. Detection of HBV DNA was done by nested-PCR using two sets of primers specific for surface and X viral genomes in serum and liver tissue of patients. Genotyping system based on PCR using type-specific primers was done for HBV-DNA positive intrahepatic samples. OBI was detected in the liver tissue in 23/40 (57.5%) of chronic HCV infected patients, 18 (78.3%) of whom belonged to group II, conferring a 90% prevalence of this group. In serum, HBV-DNA was detected in 9/40 patients (22.5%), 7 (77.8%) of whom belonged to group II. Among the 23 positive intrahepatic HBV-DNA samples studied, HBV-genotype D (34.8%) and B (26.1%) were more predominant, whereas HBV-genotype C (13.1%) and A (8.7%) infections were the least observed, respectively; mixed genotypes were detected in 17.4% (n=4), 3 of them were with HBV-genotype D and B, and 1 was with HBV-genotype C and A.In conclusion OBI is a fact in our community; it was detected in liver tissue of chronic HCV-infected patients, especially in cases of chronic HCC. In addition, OBI might be related to severity of necroinflammatory activity and fibrosis. Large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population. Also, detection of intrahepatic HBV-DNA is more useful in diagnosis of OBI.

The prevalence of occult hepatitis B virus infection (OBI) among people with a family history of chronic hepatitis B virus (HBV) infection is unclear. Serum samples were collected from 747 hepatitis B surface antigen (HBsAg)-negative people with a family history of HBV infection and 579 HBsAg-negative volunteer blood donors. The presence of HBV DNA was evaluated using nested PCR with primers specific for the X, S, and C regions of HBV. The Pre-S1/Pre-S2/ S region PCR products for the OBI group and their family members with chronic HBV infection (control group) were sequenced and compared. The prevalence of OBI was 8.0% (60/747) among HBsAg-negative people with a family history of chronic HBV infection, compared to 2.6% (15/579) among the blood donors (P < 0.05). The prevalence of HBV genotype B infection was lower in the OBI group than in the control group (P = 0.031). The substitution rates in the major hydrophilic region and the "a" determinant seemed to be higher in the OBI group (0.893 vs. 0.507; 1.042 vs. 0.403, respectively), and stop codon mutations more frequent in the OBI sequences (OBI: 2/26, 7.7% vs. 0/31, 0%). However, none of these differences was statistically significant (P = 0.237, 0.199, 0.201, respectively). In summary, the prevalence of OBI among HBsAg-negative people with a family history of chronic HBV infection was significantly higher than that in Chinese blood donors. However, S region mutations and the escape mechanism are not likely to be the major causes of increased prevalence of OBI.

BackgroundAll Chinese blood centers have implemented mini pool (MP) HBV nucleic acid testing (NAT) together with HBsAg ELISA in routine donor screening since 2015. The prevalence of occult hepatitis B virus infection (OBI) in donors from different regions varies, and the molecular characterization of the HBV DNA and clinical outcomes of these OBIs remain largely unexplored.MethodsBlood donations from Heyuan city in Southern China were screened by HBsAg ELISA and HBV MP8 NAT. Donations with HBsAg-/HBV DNA+ were collected for this study. Molecular characterizations of HBV DNAs were further analyzed by various DNA amplification assays including quantitative PCR (qPCR) and nested PCR, amplifying the basic core and pre-core promoter regions (BCP/PC). The HBsAg (S) region from HBV DNA was isolated by high-volume nucleic acid extraction. Notable mutations were identified by comparison to the HBV reference sequences. The clinical outcomes of the donors with OBIs were further followed for nearly 3 years.ResultsSeventy OBIs from 44,592 donations (0.15%) that we identified and reported previously were enrolled for this current study. HBV sequences were obtained from 44/70 OBIs, and genotyping analysis showed that 42/44 (95.2%) OBIs were genotype B, and 2/44 (4.8%) were genotype C. Interestingly, mutation analysis revealed that various mutations including M133L/T, F134L, P142L, V168A, R169H, S174N, L175S, and V177A of HBV DNA affecting HBsAg detection were observed in genotype B OBIs. Two notable mutations, T47K and L53S, were identified in genotype C OBIs. Follow-up studies showed that 3/31 (9.7%) OBIs converted to HBsAg+ as chronic infections while 1/31 (3.2%) HBV DNA was undetectable (classified as recovery) and 27/31 (87.1%) remained as OBIs.ConclusionVarious notable mutations affecting HBsAg detection were observed in blood donors with OBIs in Heyuan city of Southern China. Follow-up studies showed that most OBIs remained as OBIs with fluctuating or low viral loads. Higher sensitive HBV ID NAT is recommended for donor screening to further reduce the transmission risk of OBIs.

Impact of occult hepatitis B virus infection on the outcome of chronic hepatitis C

To analyze the relationship between miR451a and occult hepatitis B virus infection (OBI) in voluntary blood donors, and to provide ideas for the identification of OBI. A total of 125 003 blood samples were collected from voluntary blood donors in our center from January 2022 to June 2023, and OBI infection was detected by blood screening. At the same time, 40 HBsAg double reagent reactive samples (S/CO>3.0) were selected as the positive control group, and 40 healthy blood donors were selected as the negative control group (normal group). The plasma miR451a level was detected, and the serum indexes of total bilirubin (TBil), alanine aminotransferase (ALT), aspartate aminotransferase (AST). The relationship between miR451a and OBI were analyzed. 54 out of 125 003 blood samples were diagnosed as OBI, and the OBI infection rate was 0.043% (54/125 003). Compared with the normal group, the relative expression of plasma miR451a in the OBI group and the positive control group was down-regulated (P < 0.05), but there was no significant difference in the relative expression of plasma miR451a between the OBI group and the positive control group (P >0.05). The HBV DNA load, TBil, ALT and AST levels in the positive control group were higher than those in the OBI group and the normal group (P < 0.05). There was no significant difference in plasma TBil, ALT and AST levels between OBI group and normal group (P >0.05). Logistic regression analysis and receiver operating curve (ROC) showed that plasma miR451a could distinguish OBI group from healthy group, and the area under the curve (AUC) was 0.904 (95%CI : 0.829-0.978). However, plasma miR451a was difficult to distinguish between OBI and HBsAg responders. Plasma miR451a can be used as a potential biomarker for HBV infection, and can be used to identify OBI in HBsAg non-reactive blood donors.

Prevalence and risk factors of isolated anti-HBc antibody and occult hepatitis B infection in hemodialysis patients: a nationwide study

Occult hepatitis B virus infection (OBI) is characterized by the absence of HBsAg and persistence of the virus genome (HBV-DNA) in liver tissue and/or blood. OBI has been reported in several clinical contexts. However, the clinical significance of OBI in tuberculosis (TB) treatment is unknown. We investigated the OBI prevalence and its impact on the risk of drug-induced liver injury (DILI) during TB treatment. This was a prospective cohort study with one hundred patients who were treated for TB from 2008 to 2015. Laboratory, clinical and demographic data of TB patients were extracted from medical records. Based on HBV-DNA testing of serum samples, an OBI prevalence of 12% was established; almost half of these patients had both anti-HBc and anti-HBs serological markers. Low CD4+ cell counts have been shown to be a risk factor for OBI among TB patients co-infected with HIV (P=.036). High DILI incidence was observed in this study. A multivariable Cox proportional hazard model was conducted and identified OBI (HR 2.98, 95% CI 1.30-6.86) as the strongest predictor for DILI when adjusted to CD4+ cell count (HR 0.38, 95% CI 0.17-0.90), ALT before TB treatment (HR 1.37, 95% CI 0.81-2.32) and TB extrapulmonary clinical form (HR 2.91, 95% CI 1.75-7.21). The main aim of this study was to highlight DILI as a clinical outcome during treatment of TB patients with OBI. Therefore, HBV-DNA testing should be considered routinely in monitoring DILI, and also in other clinical implications associated with OBI, reduce morbidity and mortality.

Occult hepatitis B virus infection (OBI) frequently occurs in patients with chronic hepatitis C (CHC) infection, but the influence of OBI on CHC outcome is still uncertain. The aim of the present study was to clarify the clinical and pathological characteristics of OBI in CHC-related hepatocellular carcinoma (HCC). DNA was obtained from serum and tumor tissue of patients with hepatitis C virus (HCV)-related HCC with negative HBsAg and from patients with HCV-related liver cirrhosis. HBV-DNA was detected using qPCR. Clinicopathological features were compared between patients with HCC with and without OBI. On the basis of positive serum and tissue HBV-DNA typing, the overall frequency of OBI was 50% in patients with HCV-related HCC. HBV genotype D was the most dominant, constituting 35.3% of HCC cases. Almost 80% of patients with OBI had anti-HBc, whereas 20% of patients had no serological markers. Tissue HBV-DNA showed significant association with positive serum HBV-DNA, anti-HBc, and genotype D. There were no clinical differences between patients with HCC with and without OBI; however, patients with OBI tended to be younger. HCC cases with positive OBI were significantly associated with positive anti-HBc antibodies and late histological grades (3-4). Multivariate logistic regression analysis revealed that the presence of OBI was a predictor of more advanced HCC histological grades in patients with HCV infection. OBI was detected in 50% of HCV-infected patients with HCC. OBI was strongly associated with the presence of anti-HBc antibodies. Patients with HCC with positive OBI were younger and had more advanced HCC histological grades.

Although a universal newborn hepatitis B (HB) immunization programme has been implemented in China, hepatitis B virus (HBV) breakthrough infection, including HB surface antigen (HBsAg)-positive infection and occult HBV infection (OBI), still occurs during infancy or childhood. Obtaining the actual prevalence of HBV infection in general children is important for preventing and controlling the spread of HB. Accordingly, we investigated the prevalence of overt infection and OBI in community children and compared the serological and virological characteristics of OBI and HBsAg carrier children to clarify the mechanisms related to OBI. In total, 6706 community children <12years of age were included from a population-based HBV seroepidemiological investigation in Northwest China. The HBsAg carrier rate in community children was 1.60% (107/6706), and the anti-HBs positive rate was 57.35% (3846/6706). Additionally, 1192 HBsAg-negative children were examined for OBI using nested PCR. The prevalence of OBI in local children was 1.26% (15/1192), and the predominant OBI genotypes were C and D. The 15 OBI children and 29 HBsAg-positive children from the same population did not have a statistical significant difference in age, gender, alanine aminotransferase (ALT), proportion of anti-HBs or anti-HBc, viral genotypes or mutations. Children with chronic overt infection had higher viral loads than OBI children (P=.004). These results suggested that HBV overt and occult infection of children was more serious in underdeveloped north-west regions. HBV neonatal immunization and catch-up programmes should be strengthened and supplemented. None of specific viral mutations or genotypes related to OBI were found. OBI may be a specific stage of HBV infection.

SummaryBackgroundDespite growing concerns about transmissibility and clinical impact, occult hepatitis B virus (HBV) infection has received little attention in the hepatitis elimination agenda. We aimed to estimate the prevalence of occult HBV infection at a global and regional scale and in specific populations.MethodsFor this systematic review and meta-analysis, we searched the MEDLINE, Embase, Global Health, and Web of Science databases for articles published in any language between Jan 1, 2010, and Aug 14, 2019. We included original articles and conference abstracts of any study design that reported the proportion of HBsAg-negative adults (aged ≥18 years) who are positive for HBV DNA (ie, people with occult HBV infection). The prevalence of occult HBV infection was pooled, using the DerSimonian-Laird random-effects model, in the general population and specific groups defined by the type of study participants (blood donors; other low-risk populations; high-risk populations; and people with advanced chronic liver disease), and stratified by HBV endemicity in each country. We also assessed the performance of anti-HBc as an alternative biomarker to detect occult HBV infection. The study was registered with PROSPERO, CRD42019115490.Findings305 of 3962 articles were eligible, allowing a meta-analysis of 140 521 993 individuals tested for HBV DNA. Overall, only two studies evaluated occult HBV infection in the general population, precluding unbiased global and regional estimates of occult HBV infection prevalence. In blood donors, occult HBV infection prevalence mirrored HBV endemicity: 0·06% (95% CI 0·00–0·26) in low-endemicity countries, 0·12% (0·04–0·23) in intermediate-endemicity countries, and 0·98% (0·44–1·72), in high-endemicity countries (p=0·0012). In high-risk groups, occult HBV infection prevalence was substantial, irrespective of endemicity: 5·5% (95% CI 2·9–8·7) in low-endemicity countries, 5·2% (2·5–8·6) in intermediate-endemicity countries, and 12·0% (3·4–24·7) in high-endemicity countries. The pooled sensitivity of anti-HBc to identify occult HBV infection was 77% (95% CI 62–88) and its specificity was 76% (68–83).InterpretationA substantial proportion of people carry occult HBV infection, especially among high-risk groups across the globe and people living in highly endemic countries. Occult HBV infection should be part of the global viral hepatitis elimination strategy.FundingNone.

Occult hepatitis B virus infection (OBI) is a low-level asymptomatic phase of HBV infection. Evidence of OBI clinical relevance is emerging but the mechanisms of its occurrence remain unclear. In this study, the molecular characteristics of 97 confirmed OBI from Chinese blood donors were analyzed and relevant mutations were identified. Recombinant HBsAg bearing these mutations were expressed in vitro and the antigenicity and HBsAg secretion properties were analyzed. Results showed that 45 (46.4%) genotype B, 50 (51.5%) genotype C, and 2 (2.1%) genotype D sequences were identified. Two groups of mutations in the S gene were significantly associated with OBI. The first group included mutations creating new N-linked glycosylation sites at positions s116, s123, s130, and s131 + s133 or removing the existing one at s146. Mutations TCT123-125NCT/NFT were associated with reduced antigenicity, while TST116-118NST, GTS130-132NTS, and TSM131-133NSS/NYT/NST were associated with varying levels of impaired HBsAg secretion. N146 mutations had no effect on HBsAg production pattern. The second group included substitutions within the S transmembrane domains TMD1-3. Only mutations C85R, L87R, L88R, and C90R within TMD2 were associated with defective HBsAg production. These mutations appear to be rare and mostly strain specific but they may contribute to the multifactorial occurrence of OBI.

BackgroundThe presence of HBV DNA in the liver (with detectable or undetectable HBV DNA in the serum) of individuals tested HBsAg negative by currently available assays is defined occult B Infection (OBI). It remains a potential transmission threat and risk to HBV chronic infection. The purpose of this study was to determine the OBI prevalence among HBsAg negative subjects and to characterize associated genotypes.MethodsBlood samples of 219 HBsAg-negative subjects tested by ELISA were collected. HBV DNA was investigated in all samples. Viral loads were determined using quantitative real-time PCR. All samples were screened for HBV markers (anti-HBc, anti-HBe, HBsAg). The Pre-S/S region of the HBV genome was sequenced. The database was analyzed using the SPSS and Epi info software. Phylogenetic analysis was performed using the BioEdit and MEGA software.ResultsOf the 219 samples, 20.1% were anti-HBc positive, 1.8% HBeAg and 22.8% were anti-HBe positive. Fifty-six (56) (25.6%) of the samples had a detectable HBV DNA and viral loads ranging from 4 IU/mL to 13.6 106 IU/mL. Sixteen of them (16/56) had a viral load < 200 IU/mL, resulting in an OBI prevalence of 7.3% (16/219) in our study. The remaining 40 subjects had viral loads > 200 IU/mL, resulting in a “false OBI” prevalence of 18.3% (40/219). HBV genotype E was predominant followed by the quasi-sub-genotype A3. A single “false OBI” strain had the characteristic mutation G145R. Other mutations were observed and all located in the major hydrophilic region (MHR) of the S gene.ConclusionThe study reported a prevalence of 7.3% of occult hepatitis B infection. It confirms the predominance of genotype E and the existence of a subgroup of quasi-sub-genotype A3 of HBV in Burkina Faso. It further provides information on the presence of “false OBI.” This study has found mutations in the major hydrophilic region (MHR) of the pre-S/S gene of HBV.