scholarly journals High Frequency Occult Hepatitis B Virus Infection Detected in Non-Resolved Donations Suggests the Requirement of Anti-HBc Test in Blood Donors in Southern China

2021 ◽  
Vol 12 ◽  
Author(s):  
Xianlin Ye ◽  
Yu Zhao ◽  
Ran Li ◽  
Tong Li ◽  
Xin Zheng ◽  
...  
Keyword(s):  
Potential Risk ◽  
Southern China ◽  
Core Promoter ◽  
Hbv Dna ◽  
High Rate ◽  
Sequencing Analysis ◽  
Base Pairs ◽  
Occult Hbv ◽  
Hbsag Detection ◽  
Hbv Transmission

BackgroundMost Chinese Blood Centers adopted mini pool (MP) nucleic acid testing (NAT) for HBV screening due to high cost of Individual donation (ID) NAT, and different proportions of MP-reactive but ID-non-reactive donations (MP+/ID−, defined as non-resolved donations) have been observed during daily donor screening process. Some of these non-resolved donations are occult HBV infections (OBIs), which pose potential risk of HBV transmission if they are not deferred. This study is aimed to further analyze these non-resolved donations.MethodsThe non-resolved plasma samples were further analyzed by serological tests and various HBV DNA amplification assays including quantitative PCR (qPCR) and nested PCR amplifying the basic core and pre-core promoter regions (BCP/PC; 295 base pairs) and HBsAg (S) region (496 base pairs). Molecular characterizations of HBV DNA+ non-resolved samples were determined by sequencing analysis.ResultsOf 17,226 MPs from 103,356 seronegative blood donations, 98 MPs were detected reactive for HBV. Fifty-six out of these 98 (57.1%) reactive MPs were resolved as HBV DNA+, but the remaining 42 pools (42.9%, 252 donations) were left non-resolved with a high rate (53.2%) of anti-HBc+. Surprisingly, among 42 non-resolved MPs, 17 contained one donation identified as OBIs by alternative NAT assays. Sequence analysis on HBV DNAs extracted from these OBI donations showed some key mutations in the S region that may lead to failure in HBsAg detection and vaccine escape.ConclusionA total of 53.2% of the non-resolved donations were anti-HBc+, and OBIs were identified in 40.5% of these non-resolved pools. Therefore, non-resolved donations with anti-HBc+ might pose potential risk for HBV transmission. Our present analysis indicates that anti-HBc testing in non-resolved donations should be used to identify OBIs in order to further increase blood safety in China.

scholarly journals Prevalence of "anti-HBc alone" among Syrian blood donors

2014 ◽  
Vol 8 (08) ◽  
pp. 1013-1015 ◽  
Author(s):  
Wael Muselmani ◽  
Wafa Habbal ◽  
Fawza Monem
Keyword(s):  
Organ Transplantation ◽  
Blood Donors ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Occult Hbv Infection ◽  
Serological Profile ◽  
Occult Hbv ◽  
Blood Screening ◽  
Hbv Transmission

Introduction: We aimed to evaluate the prevalence of "anti-HBc alone" among Syrian blood donors, highlighting the possibility of representing occult HBV infection. Methodology: Sera of 3,896 healthy blood donors were tested for both HBsAg and anti-HBc. HBsAg-negative, anti-HBc-positive samples were further tested for the antibodies to HBsAg (anti-HBs), and "anti-HBc alone" sera were tested for HBV DNA. Results: Of 3,830 HBsAg-negative donors, 63 were "anti-HBc alone" donors, five of whom were HBV DNA positive. Conclusions: Greater consideration should be given to the "anti-HBc alone" serological profile in blood screening, premarital testing, organ transplantation tests, and other HBV transmission-related procedures in Syria.

scholarly journals Characterization of the Occult Hepatitis B Virus Variants Circulating among the Blood Donors from Eastern India

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Avik Biswas ◽  
Rajesh Panigrahi ◽  
Partha Kumar Chandra ◽  
Arup Banerjee ◽  
Sibnarayan Datta ◽  
...  
Keyword(s):  
Blood Donors ◽  
Core Promoter ◽  
Pcr Amplification ◽  
High Rate ◽  
Basal Core Promoter ◽  
Occult Hbv Infection ◽  
Occult Hepatitis ◽  
Hbv Genotypes ◽  
Positive Hbsag ◽  
Occult Hbv

A previous study from West Bengal documented very high rate of occult HBV infection (OBI) among the HBsAg negative blood donors. This study was aimed to characterize the OBI strains circulating among the blood donors and to estimate the risk associated with the prevailing viral variants/mutants. Blood samples from 2195 voluntary blood donors were included in the study. HBsAg, HBeAg, anti-HBc, and anti-HBs statuses of the samples were done by ELISA based detection. PCR amplification and sequencing were done to determine HBV genotypes, basal core promoter (BCP), and precore (Pre-C) mutations. Among the study samples, 268 were anti-HBc positive/HBsAg negative, among which 65 (24.25%) were HBV DNA positive. Phylogenetic analysis revealed the presence of HBV/D (87.23%), HBV/A (8.51%), and HBV/C (4.26%) (P<0.0001).HBV/D3 (65.85%) was the significantly prevalent subgenotype over HBV/D2 (26.83%) and HBV/D1 (7.31%) (P=0.0003). Considerable prevalence of differential BCP (1752C, 1753C, 1762T/1764A, 1753C+1762T/1764A, 1773C, and 1814C) and reverse transcriptase (rt) gene (rtI91L, rtL93P, rtS106C, rtR110G, rtN118T, rtS119T, rtY126H, rtG127W/R, rtC136R, and rtY158H) mutations was identified. Association of specific HBV subgenotypes with OBI was interesting and needs further study. Clinically relevant mutations were prevalent among the OBI strains which are of serious concern.

scholarly journals Molecular characteristics of HBV infection among blood donors tested HBsAg reactive in a single ELISA test in southern China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xianlin Ye ◽  
Tong Li ◽  
Ran Li ◽  
Heng Liu ◽  
Junpeng Zhao ◽  
...  
Keyword(s):  
Viral Load ◽  
Hepatitis B ◽  
Nested Pcr ◽  
Blood Donors ◽  
Southern China ◽  
Core Promoter ◽  
Elisa Test ◽  
Hbv Infection ◽  
Molecular Characteristics ◽  
Blood Samples

Abstract Background Hepatitis B virus (HBV) infection is a major concern for blood safety in high-prevalence HBV countries such as China. In Shenzhen, dual hepatitis B surface antigen (HBsAg) enzyme-linked immunosorbent assays (ELISAs) have been adopted in parallel with nucleic acid testing (NAT) for donors for over a decade. A small proportion of blood donors test reactive (R) for HBsAg but negative through routine NAT, which can lead to HBV infection with an extremely low viral load. Objectives We aimed to investigate and analyze the molecular characteristics of HBV among blood donors that tested HBsAg R in a single ELISA test. Methods Blood donations were evaluated in this study if confirmed HBsAg R through one of two ELISA kits. Samples with non-reactive (NR) results by NAT were collected and tested for HBsAg by chemiluminescent microparticle immunoassay (CLIA) with a neutralization test. The level of HBsAg was further assessed by electrochemiluminescence immunoassay (ECLIA). The viral basic core promoter (BCP) and pre-core (PC) and S regions were amplified by nested PCR. Quantitative real-time PCR (qPCR) for viral load determination and individual donation (ID)-NAT were adopted simultaneously. HBsAg was confirmed with CLIA, ECLIA, nested PCR, qPCR, and ID-NAT. Results Of the 100,252 donations, 38 and 41 were identified as HBsAg R with Wantai and DiaSorin ELISA kits, respectively. Seventy-nine (0.077%, 79/100,252) blood samples with ELISA R-NR and NAT NR results were enrolled in the study. Of these, 17 (21.5%,17/79) were confirmed as HBsAg-positive. Of the 14 genotyped cases, 78.6% (11/14) were genotype B, and C and D were observed in two and one sample, respectively. Mutations were found in the S gene, including Y100C, Y103I, G145R, and L175S, which can affect the detection of HBsAg. A high-frequency mutation, T1719G (93.3%), was detected in the BCP/PC region, which reduced the viral replication. Conclusion A small number of blood samples with HBsAg ELISA R-NR and NAT NR results were confirmed as HBV infection, viral nucleic acids were found in most of the samples through routine NAT methods. It is necessary to employ more sensitive and specific assays for the detection of HBV infection among blood donors.

Human c-fms proto-oncogene: comparative analysis with an abnormal allele

1985 ◽  
Vol 5 (2) ◽  
pp. 422-426
Author(s):  
J S Verbeek ◽  
A J Roebroek ◽  
A M van den Ouweland ◽  
H P Bloemers ◽  
W J Van de Ven
Keyword(s):  
Comparative Analysis ◽  
Dna Sequencing ◽  
Sequencing Analysis ◽  
Base Pairs ◽  
Small Deletion ◽  
Viral Oncogene ◽  
Close Proximity ◽  
Genetic Sequences ◽  
Dna Sequencing Analysis

The organization of the human c-fms proto-oncogene has been determined and compared with an abnormal allele. The human v-fms homologous genetic sequences are dispersed discontinuously and colinearly with the viral oncogene over a DNA region of ca. 32 kilobase pairs. The abnormal c-fms locus contains a small deletion in its 3' portion. DNA sequencing analysis indicated that it was 426 base pairs in size and located in close proximity to a putative c-fms exon.

Characterization of oocyte-expressed GDF9 gene in buffalo and mapping of its TSS and putative regulatory elements

Zygote ◽  
2012 ◽  
Vol 21 (2) ◽  
pp. 115-124 ◽  
Author(s):  
B. Roy ◽  
S. Rajput ◽  
S. Raghav ◽  
P. Kumar ◽  
A. Verma ◽  
...  
Keyword(s):  
Core Promoter ◽  
Regulatory Elements ◽  
Vital Role ◽  
Minimal Promoter ◽  
Base Pairs ◽  
Specific Expression ◽  
Oocyte Competence ◽  
Tata Element ◽  
Putative Transcription Factor ◽  
E Boxes

SummaryIn spite of emerging evidence about the vital role of GDF9 in determination of oocyte competence, there is insufficient information about its regulation of oocyte-specific expression, particularly in livestock animals. Because of the distinct prominence of buffalo as a dairy animal, the present study was undertaken to isolate and characterize GDF9 cDNA using orthologous primers based on the bovine GDF9 sequence. GDF9 transcripts were found to be expressed in oocytes irrespective of their follicular origin, and shared a single transcription start site (TSS) at –57 base pairs (bp) upstream of ATG. Assignment of the TSS is consistent with the presence of a TATA element at –23 of the TSS mapped in this study. Localization of a buffalo-specific minimal promoter within 320 bp upstream of ATG was consolidated by identification of an E-box element at –113bp. Presence of putative transcription factor binding sites and other cis regulatory elements were analyzed at ~5 kb upstream of TSS. Various germ cell-specific cis-acting regulatory elements (BNCF, BRNF, NR2F, SORY, Foxh1, OCT1, LHXF etc.) have been identified in the 5′ flanking region of the buffalo GDF9 gene, including NOBOX DNA binding elements and consensuses E-boxes (CANNTG). Presence of two conserved E-boxes found on buffalo sequence at –520 and –718 positions deserves attention in view of its sequence deviation from other species. Two NOBOX binding elements (NBE) were detected at the –3471 and –203 positions. The fall of the NBE within the putative minimal promoter territory of buffalo GDF9 and its unique non-core binding sequence could have a possible role in the control of the core promoter activity.

scholarly journals Occult Hepatitis B Virus Infection: A Review Update

2018 ◽  
Vol 5 (1) ◽  
pp. 32-38
Author(s):  
Arifa Akram
Keyword(s):  
Dna Amplification ◽  
Epidemiological Data ◽  
Diagnostic Techniques ◽  
Hbv Dna ◽  
Detection Methods ◽  
Current Evidence ◽  
Hbv Reactivation ◽  
Occult Hbv Infection ◽  
Occult Hepatitis ◽  
Occult Hbv

Occult HBV infection (OBI) is defined as HBV DNA detection in serum or in the liver by sensitive diagnostic tests in HbsAg negative individuals with or without serologic markers of previous viral exposure. Since OBI was first described in the late 1970s, there has been increasing concern in this topic. OBI can be both a source of virus contamination in blood and organ donations and the reservoir for full blown hepatitis after reactivation. HBV reactivation depends on viral and host factors but these associations have not been analyzed thoroughly. Although the exact mechanism of OBI yet not proved, intrahepatic persistence of viral covalently closed circular DNA under the host’s strong immune suppression of HBV replication and gene expression seems to be a cause. Current evidence suggests that OBI can favour the progression of fibrosis, cirrhosis, hepatocellular carcinoma and post transfusion hepatitis (PTH). Epidemiological data regarding the global prevalence of OBI vary due to the use of detection methods of different sensitivity and specificity. Appropriate diagnostic techniques must be adopted. Sensitive HBV DNA amplification assay is the gold standard assay for detection of OBI.Bangladesh Journal of Infectious Diseases 2018;5(1):32-38

scholarly journals Analysis of Transcriptional Activation at a Distance in Saccharomyces cerevisiae

2007 ◽  
Vol 27 (15) ◽  
pp. 5575-5586 ◽  
Author(s):  
Krista C. Dobi ◽  
Fred Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Target Gene ◽  
Core Promoter ◽  
Striking Difference ◽  
Base Pairs ◽  
Long Distance ◽  
Factors Affecting ◽  
Promoter Specificity

ABSTRACT Most fundamental aspects of transcription are conserved among eukaryotes. One striking difference between yeast Saccharomyces cerevisiae and metazoans, however, is the distance over which transcriptional activation occurs. In S. cerevisiae, upstream activation sequences (UASs) are generally located within a few hundred base pairs of a target gene, while in Drosophila and mammals, enhancers are often several kilobases away. To study the potential for long-distance activation in S. cerevisiae, we constructed and analyzed reporters in which the UAS-TATA distance varied. Our results show that UASs lose the ability to activate normal transcription as the UAS-TATA distance increases. Surprisingly, transcription does initiate, but proximally to the UAS, regardless of its location. To identify factors affecting long-distance activation, we screened for mutants allowing activation of a reporter when the UAS-TATA distance is 799 bp. These screens identified four loci, SIN4, SPT2, SPT10, and HTA1-HTB1, with sin4 mutations being the strongest. Our results strongly suggest that long-distance activation in S. cerevisiae is normally limited by Sin4 and other factors and that this constraint plays a role in ensuring UAS-core promoter specificity in the compact S. cerevisiae genome.

The risk of hepatitis B virus infection by transfusion in Kumasi, Ghana

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2419-2425 ◽  
Author(s):  
Jean-Pierre Allain ◽  
Daniel Candotti ◽  
Kate Soldan ◽  
Francis Sarkodie ◽  
Bruce Phelps ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Blood Donors ◽  
Hepatitis B Surface Antigen ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Sub Saharan Africa ◽  
B Virus ◽  
Sub Saharan ◽  
Hbv Transmission

The risk of hepatitis B virus (HBV) transmission by transfusion in sub-Saharan Africa is considered to be relatively low, and testing of blood donors is often not done or is done relatively poorly. To re-examine this attitude, we identified HBV chronically infected blood donors from a major hospital in Ghana with a range of hepatitis B surface antigen (HBsAg) assays. Test efficacy was estimated using HBV DNA as a gold standard, and the risk of HBV infection in blood recipients was estimated for different testing strategies. Particle agglutination, dipstick, and enzyme immunoassay (EIA) HBsAg screening detected 54%, 71%, and 97% of HBV infectious donors, respectively. The risk of HBV transmission to recipients less than 10 years old ranged between 1:11 and 1:326 with blood unscreened and screened by EIA, respectively. For older recipients, the risk decreased a further 4-fold because of the high frequency of natural exposure to HBV. A total of 98% of HBsAg-confirmed positive samples contained HBV DNA. HBV DNA load was less than 1 × 104 IU/mL in 75% of HBsAg-reactive samples, most of them anti-HBe reactive. Approximately 0.5% of HBsAg-negative but anti-HBc-positive samples contained HBV DNA. The use of sensitive HBsAg tests is critical to prevent transfusion transmission of HBV infection to young children in a population with a 15% prevalence of chronic HBV infection in blood donors. However, this will not have much effect on the prevalence of this infection unless other strategies to protect children from infection are also advanced in parallel.

scholarly journals Occult hepatitis B infection among individuals belonging to the aboriginal Nicobarese tribe of India

2014 ◽  
Vol 8 (12) ◽  
pp. 1630-1635 ◽  
Author(s):  
Haimanti Bhattacharya ◽  
Debdutta Bhattacharya ◽  
Subarna Roy ◽  
Attayur Purushothaman Sugunan
Keyword(s):  
Hepatitis B ◽  
Hbv Dna ◽  
Hepatitis B Infection ◽  
Tribal Community ◽  
Serum Samples ◽  
Occult Hbv Infection ◽  
Occult Hepatitis ◽  
Occult Hbv ◽  
The People ◽  
Occult Hepatitis B

Introduction: The long-lasting persistence of hepatitis B virus (HBV) genomes in the liver (with or without detectable HBV DNA) of individuals with negative for HBV surface antigen (HBsAg) is termed occult HBV infection (OBI). The present study is a part of the follow up on efficacy of vaccination, 10 years post inception, and was designed to understand the prevalence of Occult Hepatitis B infection (OBI) among the aboriginal Nicobarese tribal community. Methodology: A total of 612 serum samples were collected and tested for various markers including HBsAg, Anti-HBs, Anti-HBc and HBV DNA. Part of S gene of the extracted HBV DNA was amplified by nested PCR. The amplified products were then subjected to sequencing. Genotyping was performed on the basis of phylogenetic relationship along with representative reference sequences from different sub genotypes. Results: The study revealed OBI in 11.1% of the people belonging to the Nicobarese tribe. Phylogenetic analysis showed only one genotype, HBV/D circulating among the Nicobarese population with ayw3 was the major serotype detected. Single or multiple amino acids substitutions were found in 5 of 34 samples (14.7%) which includes I110T, P120T, P/T127I, A128P, M133L and G159V. Conclusions: The detection of OBI among these aboriginal tribes is of great concern and stresses the need for the continuous surveillance as it may contribute to the progression of liver disease to a more advanced stage.

Sign in / Sign up

Export Citation Format

Share Document