Patients with Asian-type DEL can safely be transfused with RhD-positive blood.

Red blood cells (RBCs) of Asian-type DEL phenotype express few RhD proteins and are typed as serologic RhD-negative (D-) phenotype in routine testing. RhD-positive (D+) RBC transfusion for patients with Asian-type DEL has been proposed but has not been generally adopted because of a lack of direct evidence regarding its safety and the underlying mechanism. We performed a single-arm multicenter clinical trial to document the outcome of D+ RBC transfusion in patients with Asian-type DEL; none of the recipients (0/42; 95% confidence interval, 0-8.40) developed alloanti-D after a median follow-up of 226 days. We conducted a large retrospective study to detect alloanti-D immunization in 4045 serologic D- pregnant women throughout China; alloanti-D was found only in individuals with true D- (2.63%, 79/3009), but not in those with Asian-type DEL (0/1032). We further retrospectively examined 127 serologic D- pregnant women who had developed alloanti-D and found none with Asian-type DEL (0/127). Finally, we analyzed RHD transcripts from Asian-type DEL erythroblasts and examined antigen epitopes expressed by various RHD transcripts in vitro, finding a low abundance of full-length RHD transcripts (0.18% of the total) expressing RhD antigens carrying the entire repertoire of epitopes, which could explain the immune tolerance against D+ RBCs. Our results provide multiple lines of evidence that individuals with Asian-type DEL cannot produce alloanti-D when exposed to D+ RBCs after transfusion or pregnancy. Therefore, we recommend considering D+ RBC transfusion and discontinuing anti-D prophylaxis in patients with Asian-type DEL, including pregnant women. This clinical trial is registered at www.clinicaltrials.gov as #NCT03727230.

Occult Hepatitis B Virus Infection and Liver Fibrosis in Chinese Patients.

BACKGROUND: The impact of hepatitis B surface antigen (HBsAg)-negative/hepatitis B virus (HBV) DNA-positive occult HBV infection (OBI) on the severity of liver fibrosis remains unclear. METHODS: A total of 1772 patients negative for HBsAg but positive for antibody to hepatitis B core antigen (HBcAg), stratified by the presence or absence of OBI, were selected for long-term carriage leading to elevation of ≥2 of 4 liver fibrosis indexes-hyaluronic acid (HA), laminin, type III procollagen peptide (PCIII), and type IV collagen (CIV)-at testing in a Chinese hospital. Patients were tested for serum viral load, HBV markers, and histopathological changes in liver biopsy specimens. RESULTS: OBI was identified in 148 patients with liver fibrosis (8.4%), who had significantly higher levels of HA, laminin, PCIII, and CIV than 1624 fibrotic patients without OBI (P < .05). In 36 patients with OBI who underwent liver biopsy, significant correlations were observed between OBI viral load and serum HA levels (P = .01), PCIII levels (P = .01), and pathological histological activity index (HAI) scores (P < .001), respectively; HAI scores and PCIII levels (P = .04); HBcAg immunohistochemical scores and HA levels (P < .001); and HBcAg immunohistochemical scores and PCIII levels (P = .03). Positive fluorescent in situ hybridization results were significantly more frequent in patients with OBIs (80.6% vs 37.5% in those without OBIs). Among patients with OBIs, HBcAg was detected in the liver tissue in 52.8% and HBsAg in 5.6%. CONCLUSIONS: OBI status appears to be associated with liver fibrosis severity.

Magnetically empowered bone marrow cells as a micro-living motor can improve early hematopoietic reconstitution.

BACKGROUND AIMS: Bone marrow-derived hematopoietic stem cell transplantation/hematopoietic progenitor cell transplantation (HSCT/HPCT) is widely used and one of the most useful treatments in clinical practice. However, the homing rate of hematopoietic stem cells/hematopoietic progenitor cells (HSCs/HPCs) by routine cell transfusion is quite low, influencing hematopoietic reconstitution after HSCT/HPCT. METHODS: The authors developed a micro-living motor (MLM) strategy to increase the number of magnetically empowered bone marrow cells (ME-BMCs) homing to the bone marrow of recipient mice. RESULTS: In the in vitro study, migration and retention of ME-BMCs were greatly improved in comparison with non-magnetized bone marrow cells, and the biological characteristics of ME-BMCs were well maintained. Differentially expressed gene analysis indicated that ME-BMCs might function through gene regulation. In the in vivo study, faster hematopoietic reconstitution was observed in ME-BMC mice, which demonstrated a better survival rate and milder symptoms of acute graft-versus-host disease after transplantation of allogeneic ME-BMCs. CONCLUSIONS: This study demonstrated that ME-BMCs serving as MLMs facilitated the homing of HSCs/HPCs and eventually contributed to earlier hematopoietic reconstitution in recipients. These data might provide useful information for other kinds of cell therapies.

Improving Photoelectric Conversion with Broadband Perovskite Metasurface.

The miniaturization and integration of optoelectronic devices require progressive size reduction of active layers, resulting in less optical absorption and lower quantum efficiency. In this work, we demonstrate that introducing a metasurface made of hybrid organic-inorganic perovskite (HOIP) can significantly enhance broadband absorption and improve photon-to-electron conversion, which roots from exciting Mie resonances together with suppressing optical transmission. On the basis of the HOIP metasurface, a broadband photodetector has been fabricated where photocurrent boosts more than 10 times in the frequency ranging from ultraviolet to visible. The device response time is less than 5.1 µs at wavelengths 380, 532, and 710 nm, and the relevant 3 dB bandwidth is over 0.26 MHz. Moreover, this photodetector has been applied as a signal receiver for transmitting 2D color images in broadband optical communication. These results accentuate the practical applications of HOIP metasurfaces in novel optoelectronic devices for broadband optical communication.

Multiple-polarization-sensitive photodetector based on a perovskite metasurface.

Most polarization-sensitive photodetectors detect either linearly polarized (LP) or circularly polarized (CP) light. Here, we experimentally demonstrate a multiple-polarization photodetector based on a hybrid organic-inorganic perovskite (HOIP) metasurface, which is sensitive to both LP and CP light simultaneously. The perovskite metasurface is composed of a HOIP antenna array on a single-crystal HOIP film. Owing to the antenna anisotropy, the absorption of linearly polarized light at the metasurface depends on the polarization angle; also, due to the mirror asymmetry of the antenna elements, the metasurface is also sensitive to different circular polarizations. Polarization-dependent photocurrent responses to both LP and CP light are detected. Our results highlight the potential of perovskite metasurfaces for integrated photoelectric applications.

Brucella Outer Membrane Lipoproteins 19 and 16 Differentially Induce Interleukin-18 Response or Pyroptosis in Human Monocytic Cells.

BACKGROUND: Brucella species are Gram-negative intracellular bacteria that causes severe inflammatory diseases in animals and humans. Two major lipoproteins (L19 and L16) of Brucella outer membrane proteins were studied to explore the association with inflammatory response of human monocytes (THP-1). METHODS: Activated THP-1 cells induced with recombinant L19 and L16 were analyzed in comparison with unlipidated forms (U19 and U16) and lipopolysaccharide (LPS) of Brucella melitensis, respectively. RESULTS: Secretion of inflammatory factors tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß was significantly increased from L19, L16, or both stimulated THP-1 cells. High secretion of IL-18 was detected only from L19-induced cells. Signaling of those cytokine responses was identified mainly through the P38-mitogen-activated protein kinase pathway, and signaling of L19-induced IL-1ß response partly occurred via necrosis factor-κB. While exploring different forms of IL-18, we found that L19-induced production of active IL-18 (18 kD) occurred through upregulating NLRP3 and activating caspase-1, whereas L16-induced production of inactive IL-18 fragments (15 kD and 16 kD) occurred through activating caspase-8/3. We also found that L19 upregulated phosphorylation of XIAP for inhibiting caspase-3 activity to cleave IL-18, whereas L16 activated caspase-3 for producing GSDME-N and leading to pyroptosis of THP-1 cells. CONCLUSIONS: Brucella L19 and L16 differentially induce IL-18 response or pyroptosis in THP-1 cells, respectively.

Role of core protein mutations in the development of occult HBV infection.

BACKGROUND & AIMS: Occult HBV infection (OBI) is associated with transfusion-transmitted HBV infection and hepatocellular carcinoma. Studies on OBI genesis have concentrated on mutations in the S region and the regulatory elements. Herein, we aimed to determine the role of mutations in the core region on OBIs. METHODS: An OBI strain (SZA) carrying 9 amino acid (aa) substitutions in the core protein/capsid (Cp) was selected by sequence alignment and Western blot analysis from 26 genotype B OBI samples to extensively explore the impact of Cp mutations on viral antigen production in vitro and in vivo. RESULTS: A large panel of 30 Cp replicons were generated by a replication-competent pHBV1.3 carrying SZA or wild-type (WT) Cp in a 1.3-fold over-length of HBV genome, in which the various Cp mutants were individually introduced by repairing site mutations of SZA-Cp or creating site mutations of WT-Cp by site-directed mutagenesis. The expression of HBcAg, HBeAg, and HBsAg and viral RNA was quantified from individual SZA and WT Cp mutant replicons in transfected Huh7 cells or infected mice, respectively. An analysis of the effect of Cp mutants on intracellular or extracellular viral protein production indicated that the W62R mutation in Cp had a critical impact on the reduction of HBcAg and HBeAg production during HBV replication, whereas P50H and/or S74G mutations played a limited role in influencing viral protein production invivo. CONCLUSIONS: W62R and its combination mutations in HBV Cp might massively affect HBcAg and HBeAg production during viral replication, which, in turn, might contribute to the occurrence of OBI. LAY SUMMARY: Occult hepatitis B virus infections (OBIs) have been found to be associated with amino acid mutations in the S region of the HBV, but the role of mutations in the core protein (Cp) remains unclear. In this study, an OBI strain (SZA) carrying 9 amino acid substitutions in Cp has been examined comprehensively in vitro and in vivo. The W62R mutation in Cp majorly reduces HBcAg and HBeAg production during HBV replication, potentially contributing to the occurrence of OBI.

Flexible Phase Change Materials for Electrically-Tuned Active Absorbers.

Phase change materials (PCMs), such as GeSbTe (GST) alloys and vanadium dioxide (VO2 ), play an important role in dynamically tunable optical metadevices. However, the PCMs usually require high thermal annealing temperatures above 700 K, but most flexible metadevices can only work below 500 K owing to the thermal instability of polymer substrates. This contradiction limits the integration of PCMs into flexible metadevices. Here, a mica sheet is chosen as the chemosynthetic support for VO2 and a smooth and uniformly flexible phase change material (FPCM) is realized. Such FPCMs can withstand high temperatures while remaining mechanically flexible. As an example, a metal-FPCM-metal infrared meta-absorber with mechanical flexibility and electrical tunability is demonstrated. Based on the electrically-tuned phase transition of FPCMs, the infrared absorption of the metadevice is continuously tuned from 20% to 90% as the applied current changes, and it remains quite stable at bending states. The metadevice is bent up to 1500 times, while no visible deterioration is detected. For the first time, the FPCM metastructures are significantly added to the flexible material family, and the FPCM-based metadevices show various application prospects in electrically-tunable conformal metadevices, dynamic flexible photodetectors, and active wearable devices.

Low prevalence of antibodies against SARS-CoV-2 among voluntary blood donors in Guangzhou, China.

Since the first case of COVID-19 reported in late December of 2019 in Wuhan, China, the SARS-CoV-2 virus has caused approximately 20 million infections and 732 thousand deaths around the world by 11 August 2020. Although the pathogen generally infects the respiratory system, whether it is present in the bloodstream and whether it poses a threat to the blood supply during the period of the outbreak is of serious public concern. In this study, we used enzyme-linked immunosorbent assay (ELISA) to screen total antibodies against SARS-CoV-2 in 2199 blood donors, who had donated blood at the Guangzhou Blood Center during the epidemic. The Ig-reactive samples were further characterized for IgA, IgG, and IgM subtypes by ELISA and viral nucleic acid by real-time polymerase chain reaction. Among the 2199 plasma samples, seven were reactive under total antibodies' screening. Further testing revealed that none of them had detectable viral nucleic acid or IgM antibody, but two samples contained IgA and IgG. The IgG antibody titers of both positive samples were 1:16 and 1:4, respectively. Our results indicated a low prevalence of past SARS-CoV-2 infection in our blood donors, as none of the tests were positive for viral nucleic acid and only 2 out of 2199 (0.09%) of samples were positive for IgG and IgA. There would be a limited necessity for the implementation of such testing in blood screening in a COVID-19 low-risk area.

Metasurface-assisted broadband optical absorption in ultrathin perovskite films.

Ultrathin hybrid organic-inorganic perovskite (HOIP) films have significant potential for use in integrated high-performance photoelectric devices. However, the relatively low optical absorption capabilities of thinner films, particularly in the long-wavelength region, pose a significant challenge to the further improvement of photoelectrical conversion in ultrathin HOIP films. To address this problem, we propose a combining of ultrathin HOIP film with plasmonic metasurface to enhance the absorption of the film effectively. The metasurface excites localized surface plasmon resonances and deflects the reflected light within the HOIP film, resulting in an obvious enhancement of film absorption. Finite-difference time-domain simulation results reveal that the far-field intensities, deflection angles, and electric field distributions can be effectively varied by using metasurfaces with different arrangements. Examination of the reflection and absorption spectra reveals that embedding a specifically designed metasurface into the HOIP film produces an obvious enhancement in broadband optical absorption compared with pure HOIP films. We further demonstrate that this broadband absorption promotion mechanism can be effective at a wide range of HOIP film thicknesses. Comparison of the absorption spectra at various incidence angles of ultrathin HOIP films with and without underlying metasurfaces indicates that the addition of a metasurface can effectively promote absorption under wide-angle incident light illumination. Moreover, by extending the metasurface structure to a two-dimensional case, absorption enhancements insensitive to the incident polarization states have also been demonstrated. This proposed metasurface-assisted absorption enhancement method could be applied in designing novel high-performance thin-film solar cells and photodetectors.

A nanoenzyme linked immunochromatographic sensor for rapid and quantitative detection of SARS-CoV-2 nucleocapsid protein in human blood.

The establishment of a simple, low-cost, high-sensitive and rapid immunoassay for detecting SARS-CoV-2 antigen in human blood is an effective mean of discovering early SARS-CoV-2 infection and controlling the pandemic of COVID-19. Herein, a smartphone based nanozyme linked immunochromatographic sensor (NLICS) for the detection of SARS-CoV-2 nucleocapsid protein (NP) has been developed on demand. The system is integrated by disposable immunochromatography assay (ICA) and optical sensor devices. Immunoreaction and enzyme-catalyzed substrate color reaction were carried out on the chromatographic strip in a device, of which the light signal was read by a photometer through a biosensor channel, and the data was synchronously transmitted via the Bluetooth to the app in-stored smartphone for reporting the result. With a limit of detection (LOD) of 0.026 ng/mL NP, NLICS had the linear detection range (LDR) between 0.05 and 1.6 ng/mL NP, which was more sensitive than conventional ICA. NLICS took 25 min for reporting results. For detection of NP antigen in clinical serum samples from 21 COVID-19 patients and 80 healthy blood donor controls, NLICS and commercial enzyme linked immunosorbent assay (ELISA) had 76.2% or 47.6% positivity, and 100% specificity, respectively (P = 0.057), while a good correlation coefficient (r = 0.99) for quantification of NP between two assays was obtained. In conclusion, the NLICS was a rapid, simple, cheap, sensitive and specific immunochromatographic sensing assay for early diagnosis of SARS-CoV-2 infection.

Flexible Ultrathin Single-Crystalline Perovskite Photodetector.

Flexible optoelectronic devices attract considerable attention due to their prominent role in creating novel wearable apparatus for bionics, robotics, health care, and so forth. Although bulk single-crystalline perovskite-based materials are well-recognized for the high photoelectric conversion efficiency than the polycrystalline ones, their stiff and brittle nature unfortunately prohibits their application for flexible devices. Here, we introduce ultrathin single-crystalline perovskite film as the active layer and demonstrate a high-performance flexible photodetector with prevailing bending reliability. With a much-reduced thickness of 20 nm, the photodetector made of this ultrathin film can achieve a significantly increased responsivity as 5600A/W, 2 orders of magnitude higher than that of recently reported flexible perovskite photodetectors. The demonstrated 0.2 MHz 3 dB bandwidth further paves the way for high-speed photodetection. Notably, all its optoelectronic characteristics resume after being bent over thousands of times. These results manifest the great potential of single-crystalline perovskite ultrathin films for developing wearable and flexible optoelectronic devices.

Novel hepatitis B virus surface antigen mutations associated with occult genotype B hepatitis B virus infection affect HBsAg detection.

The causative factors of occult hepatitis B infection are complicated and not yet been fully elucidated. Mutations in hepatitis B virus (HBV) S gene are one of the factors may contributing to occult infection. In this study, 89 blood donors with genotype B occult HBV infection were investigated. Fifty-seven hepatitis B surface antigen (HBsAg)-positive/HBV DNA-positive blood donors served as control group for comparison. Occult HBV-related mutations with a high incidence (P < .05) in the S gene were identified. To further verify these occult infection-related mutations, a conservative full-gene expression vector of HBV B genotype (pHBV1.3B) was constructed. Then, the mutant plasmids on the basis of pHBV1.3B were constructed and transfected into HepG2 cells. Extracellular as well as intracellular HBsAg was analysed by electrochemical luminescence and cellular immunohistochemistry. Ten occult infection-related mutations (E2G, Q101R, K122R, M133T, D144E, G145R, V168A, S174N, L175S and I226S) were significantly more frequent in the occult infection group (P < .05). Five of the ten mutations (E2G, D144E, G145R, V168A and S174N) strongly decreased extracellular HBsAg level (P < .05) in the transfection system. Notably, the E2G mutation had the most significant impact on the ratio of extracellular HBsAg (3.8% vs pHBV1.3B) and intracellular HBsAg (239.3% vs pHBV1.3B) (P < .05), and the fluorescence density of E2G mutant HBsAg was significantly higher than that of pHBV1.3B (P < .0001). Hence, ten mutations were associated with genotype B occult HBV infection; E2G and V168A were novel mutations which we confirmed significantly affect HBsAg detection. E2G might cause HBsAg secretion impairment that results in intracellular accumulation and a decrease in HBsAg secretion.

Metagenomic analysis of potential pathogens from blood donors in Guangzhou, China.

OBJECTIVES: This study aimed to identify the emerging/reemerging pathogens in blood donation samples. BACKGROUND: A metagenomic analysis has previously been used to look for pathogens but in this study, the relationship with aminotransferase (ALT) is described. METHODS/MATERIALS: Excluding samples reactive to hepatitis B virus, hepatitis C virus, human immunodeficiency syndrome virus or syphilis and plasma samples were stratified into three groups of ALT levels (IU/L): A ≤ 50, B 51 to 69 and C ≥ 70, respectively. Each group was mixed in a pool of 100 samples, from which DNA and cDNA libraries were established for next generation sequencing and analysis. Pathogens of interest were identified by immunoassays, nested-polymerase chain reaction, phylogenetic analysis and pathogen detection in follow-up donors. RESULTS: Several new or reemerging transfusion-transmitted pathogens were identified; Streptococcus suis, Babesia species and Toxoplasma gondii were found in the three ALT groups, Epstein-Barr virus (EBV) only in group C. Ten S. suis nucleic acid positive samples were detected, all closely phylogenetically related to reference strains. A donor in group A carried both S. suis genome and specific IgM in follow-up samples. This strain was identified as nontoxic S. suis. Five samples contained a short fragment of Babesia species SpeI-AvaI gene, while T. gondii was identified in 20 samples as a short fragment of 18S rDNA gene. In group C, two samples contained EBV genome. CONCLUSIONS: Blood donations that contained S. suis, Babesia species and T. gondii sequences might represent potential transfusion risks. EBV, a potential cause of elevated ALT, was detected. Metagenomic analysis might be a useful technology for monitoring blood safety.

Hydrops fetalis associated with anti-CD36 antibodies in fetal and neonatal alloimmune thrombocytopenia: Possible underlying mechanism.

OBJECTIVES: In the present study, we asked whether anti-CD36 antibodies impair the maturation of erythropoietic stem cells to mature red blood cells (RBCs), leading to anaemia and hydrops fetalis (HF). BACKGROUND: Recent studies have shown the importance of anti-CD36 antibodies in the development of Fetal/Neonatal Alloimmune Thrombocytopenia (FNAIT). In comparison to other types of antibody-mediated FNAIT, anti-CD36 antibodies are frequently associated with anaemia and HF. As mature RBCs do not express CD36, the reason for this phenomenon is currently not fully understood. MATERIAL AND METHODS: A case of FNAIT with signs of HF was characterised in this study. Maternal anti-CD36 antibodies were isolated by an absorption/elution approach. We cultured haematopoietic stem cells (HSCs) with purified anti-CD36 antibodies, and the formation of burst-forming unit-erythroid and colony-forming unit-erythroid (CFU-E/BFU-E) cells was analysed. Apoptosis of HSCs was also investigated. RESULTS: Analysis of the mother showed type-1 CD36 deficiency. Anti-CD36 antibodies were found in maternal serum, as well as on fetal platelets, by ELISA, and the specificity of these antibodies was further substantiated by flow cytometry. In comparison to control IgG, incubation of HSCs with purified anti-CD36 antibodies led to a significant reduction in CFU-E/BFU-E cell formation, and this result was associated with an increased number of apoptotic CD34+ erythroid/myeloid precursor cells. Administration of intra-uterine transfusion with washed RBCs was effective in improving fetal anaemia. CONCLUSIONS: Anti-CD36 antibodies may cause anaemia and trigger HF through apoptosis of CD34+ erythroid/myeloid precursor cells. However, the contribution of other cells must also be taken into account.

HCV genotype 6 prevalence, spontaneous clearance and diversity among elderly members of the Li ethnic minority in Baisha County, China.

The epidemiology of hepatitis C virus varies widely across geographical regions and ethnic groups. Our previous study showed that 6 strains isolated from Baisha County, Hainan Island, China, were all new genotype 6 (gt6) subtypes which differed significantly from subtypes of other regions. In the current study, we conducted a comprehensive epidemiological survey of HCV in the Li ethnic group, native to Baisha County. Anti-HCV antibodies were detected by 2 independent ELISAs in all participants, and positive results confirmed by the recombinant immunoblot assay (RIBA) and HCV RNA viral loads were measured. Univariate chi-square test and multivariable logistic regression analyses were used to determine the risk factors for HCV infection and spontaneous clearance rates. Indeterminate RIBA results were excluded or included in analyses; consequently, findings were expressed as a range. Direct sequencing of partial regions within NS5B and E1 was employed for genotyping. Among 1682 participants, 117 to 153 were anti-HCV positive (7.0%-9.1%), with 42.7%-52.6% confirmed to have cleared infection. Anti-HCV positivity was associated with older age (≥60 years) (OR = 0.02, 95% CI 0.01-0.05, P < 0.01) and surgery (OR = 2.75, 95% CI 1.36-5.57, P < 0.01), with no significant difference found between the HCV infection group and the HCV spontaneous clearance group. The gt6 subtype distribution characteristics of Baisha County were unique, complex and diverse. The sequences did not cluster with known gt6 subtypes but formed 4 Baisha community-specific groups. HCV infection in members of the Li minority ethnic group is characterized by high prevalence rates in the elderly, high spontaneous clearance rates and broad gt6 diversity.

Association of HLA-DQB1*03:01 and DRB1*11:01 with spontaneous clearance of hepatitis C virus in Chinese Li ethnicity, an ethnic group genetically distinct from Chinese Han ethnicity and infected with unique HCV subtype.

Specific human leukocyte antigen (HLA) class I and class II alleles have been associated with spontaneous clearance or persistent infection of hepatitis C virus (HCV), which seemed to be restricted by the host's ethnicity and viral genotype. Recently we reported a high prevalence and spontaneous clearance rate of HCV in a cohort of Chinese Li ethnicity who were infected with new variants of HCV genotype 6. In this study, we found that the distribution of HLA class I and class II alleles in HCV infected individuals of Chinese Li ethnicity (n = 143) was distinct from that of Chinese Han ethnicity which was reported in our previous study. HLA-DRB1*11:01 and DQB1*03:01 were more prevalent in Chinese Li subjects who cleared HCV spontaneously than those who were chronically infected (P = .036 and P = .024, respectively), which were consistent with our previous report regarding the Chinese Han population. Multivariate logistic regression analysis showed that DQB1*03:01 (odds ratio = 3.899, P = .017), but not DRB1*11:01, associated with HCV spontaneous clearance, independent of age, sex, and IFNL3 genotype. Because DQB1*03:01 and DRB1*11:01 were tightly linked because of linkage disequilibrium, our results clearly supported the associations of these two alleles with HCV spontaneous clearance in Chinese Li as well as Han ethnicity.

A signal amplification system on a lateral flow immunoassay detecting for hepatitis e-antigen in human blood samples.

Hepatitis B e-antigen (HBeAg) is the secretory form of the nucleocapsid of the hepatitis B virus (HBV), which is a marker of viral replication. In this study, a novel signal amplification system (SAS) based on the lateral flow immunoassay (LFIA) was used for rapid detection of HBeAg in blood samples from patients or blood donors. In this assay, the detection antibody was conjugated with gold nanoparticles (GNPs), and the capture antibody was labeled with biotin. The presence of targeting antigen HBeAg in blood sample would act as a bridge with biotinylated captured antibody and GNP-conjugated detection antibody to form the dendritic nanoparticle complex. The dendritic complexes in the sample solution were migrated and immobilized on the testing line of strip coated with antibiotin antibodies. Signal intensity was massively amplified by the SAS, which was positively correlated with the concentration of targeting antigen in the blood sample and was assessed by eyes or strip scanner. The SAS worked only when targeting antigens were present in the sample. By using this SAS-LFIA, we were able to detect a very low concentration of HBeAg (9 ng/mL), which was 27-fold sensitive than that by conventional LFIA (cLFIA). A number of 420 blood samples were detested by this novel SAS-LFIA, the results were in accordance with those of enzyme-linked immunosorbent assay (ELISA) completely, while the cLFIA missed an HBeAg-positive sample. In conclusion, the novel SAS has high specificity and sensitivity, which can be used to replace the conventional rapid test and ELISA in clinical diagnosis.

Characterization of monocytic and granulocytic subsets of myeloid-derived suppressor cells in blood donors with occult hepatitis B virus infection.

Myeloid-derived suppressor cells (MDSCs) accumulate from many diseases. MDSCs are rarely explored in occult hepatitis B virus infection (OBI). The frequency of monocytic MDSCs (M-MDSCs) and granulocytic MDSCs (G-MDSCs) in OBI carriers was analyzed for correlation with clinical parameters, which was no different between OBI and healthy individuals, whereas the frequency of M-MDSCs but G-MDSCs in OBI was significantly lower than that observed in chronic hepatitis B carriers (0.4% vs 0.7%, P = 0.0004). The frequency of MDSCs was not correlated with clinical parameters and viral load of OBI, suggesting that the absence of HBsAg in OBI carriers might not induce the accumulation of MDSCs.

Nearly half of Ultrio plus NAT non-discriminated reactive blood donors were identified as occult HBV infection in South China.

BACKGROUND: Blood donor plasma samples were detected by the Ultrio Plus NAT system for HBV, HCV and HIV-1 in Shenzhen blood center, China. Reactive samples underwent further discriminatory testing of a single virus by the same methodology. A large number of cases of non-discriminated reactive (NDR) donors were found, leaving potential risk of transmitting HBV if not deferrals. This study identified those non-discriminated samples. METHODS: The NDR plasma samples from blood donation screening were detected and classified by additional molecular and serological tests. Molecular characterizations of DNA+ NDR were determined by sequencing analysis. RESULTS: A number of 259 (0.21%) NDR plasma samples from screening of 123,280 eligible blood donors were detected, which presented a higher rate (91.1%) of anti-HBc reactivity and nearly half (46.7%) of HBV DNA+ that classified as occult HBV infection (OBI). Most OBI strains were wild-type HBV, but some substitutions V168A, S174 N, V177A, Q129R/L/H, G145A/R in S region of genotype B (OBIB) and T47K/V/A, P49H/L, Q101R/H/K, S174 N, L175S, V177A, T118 M/R/K, G145R/A/K/E, R160K/N in S region of genotype C (OBIC) strains were identified in high frequency. CONCLUSION: Nearly half of NDR blood samples were identified as OBI, in which a number of important mutations were detected. NDR donation might have potential risk for HBV transmission, but need to be further investigated.