Comparison on Detection Results of PRV Wild Virus Antibody Provided by Different Institutions

The detection results from different institutions were performed at the first stage of PRV wild virus antibody supervision in swine breeding. The serum samples were collected from 71 individuals and each individual was sampled twice at one week interval. The results showed that the positive coincidences for gE antibody between two institutions were 35.71% and 45.45 % ：espectively, with the total detection coincidences of 87.32% and 91.55% correspondingly. The positive coincidences for gE antibody between the two detections of each institution were 40.00% and 75.00% respectively, with the total detection coincidences of 87.32% and 97.18% correspondingly. It indicates that it is very necessary to screen the detection institution at the first supervision stage of PRV wild vires for swine population.

Highly Sensitive and Specific Monoclonal Antibody-Based Serological Methods for Rice Ragged Stunt Virus Detection in Rice Plants and Rice Brown Planthopper Vectors

Rice ragged stunt virus（RRSV） is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein（CP） gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21（DE3） using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody（MAb） against RRSV was obtained by fusing mouse myeloma cells（Sp 2/0） with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay（ACP-ELISA）, a dot enzyme-linked immunosorbent assay（dot-ELISA）, and immunocapture-RT-PCR（IC-RT-PCR） assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1：40 960, 1：1 280 and 1：655 360（w/v, g mL-1）, respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1：12 800 and 1：1 600（an individual planthopper μL-1）, respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.

GENE ENGINEERING EB VIRUS MEMBRANE ANTIGEN IN DETECTION OF MA-IgA ANTIBODY(COMPARISON WITH VCA-IgA AND EA-IgA ANTIBODIES)

With gene engineering EB virus membrane antigen as the diagnostic antigen, indirect immunofluo-rescence (IF) assay was used to detect IgA antibody against EB virus membrane antigen (MA-IgA) in sera from 202 nasopharyngeal carcinoma (NPC) patients and 315 controls (normal and patients with other tumors). MA-IgA antibody was positive in 96.8% of the pretreatment NPC patients with a GMT of 1:36.3. MA-IgA detection by this method was more sensitive than EA-IgA detection by IE. In contrast, patients with tumors other than NPC were negative for MA-IgA antibody. 9.1% of VCA-IgA positive persons were MA-IgA positive with a GMT of less than 1:5. No MA-IgA positive was found in VCA-IgA negatives. The results indicated that this method was relatively specific. In the treatment group, the positive rate and GMT of MA-IgA antibody declined with increase in survival time and the decline was faster than VCA-IgA. When recurrence or distant metastasis developed, similar to VCA-IgA and EA-IgA antibodies, the positive rate and GMT of MA-IgA antibody increased to its pretreatment level. Therefore, MA-IgA detection might be valuable in the early diagnosis and monitor of NPC.

Comparative Study on 4 EIA Kits for Screening Antibody to Hepatitis C Virus in Pooled Sera

Four enzyme immunoassay (EIA) test kits, 1 Canadian product and 3 Chinese products,were used in the comparative study. Each pool consisted of 5 sera, and the 5 single sera were tested as controls. The tests were carried out according to the instructions, keeping the same dilution of each serum in single and pool samples. It was found that with the Canadian kit,the positive and negative results of opled sera had no difference from that of the controls (P>0. 10). In the case of Chinese Yali and Kehua kits, the positive results of pooled sera showed no difference from the controls (P >0. 10), but the optical density (OD) of negative opls were increased (P < 0. 01 ), though quite distant from the cut-off values. In the case of Changzheng kit, the OD of opitive opls were significantly lower than those of the controls (P < 0. 05 ), and weak positive samples missed the detection. However this problem could be overcome by blocking the microwells beforehand. Our experiment demonstrate that not all EIA test kits are suitable for screening opls for antithey to hepatitis C virus, and that it is important to assess the sensitivity of the EIA kit to be used for this purpose.

Is there a need for universal double reflex testing of HBsAg-positive individuals for hepatitis D infection?

Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study.

Hepatitis C virus micro-elimination:Where do we stand?

Hepatitis C virus (HCV) elimination by 2030, using direct-acting antiviraltreatments, has been promoted by the World Health Organization. Thisachievement is not attainable, however, particularly after the 2020 pandemic ofthe coronavirus disease 2019. Consequently, the more realistic objective ofeliminating HCV from population segments for which targeted strategies ofprevention and treatment are easily attained has been promoted in Europe, as avalid alternative. The underlying idea is that micro-elimination will ultimatelylead to macro-elimination. The micro-elimination strategy may target differentspecific populations and at-risk groups. Different settings, including prisons andhospitals, have also been identified as micro-elimination scenarios. In addition,dedicated micro-elimination strategies have been designed that are tailored at thegeographical level according to HCV epidemiology and individual country’sincome. The main elements of a valid and successful micro-elimination project arereliable epidemiological data and active involvement of all the stakeholders.Community involvement represents another essential component for a successfulprogram.

CLINICAL SIGNIFICANCE OF DETECTING SERUM ANTIBODIES TO NUCLEOPROTEIN AND GLYCOPROTEIN G_2 OF HANTAAN VIRUS IN PATIENTS WITH HEMORRHAGIC FEVER WITH RENAL SYNDROME

Antibody blocking enzyme linked immunosorbent assays, respectively detecting antibodies to Hantaan virus nucleoprotein (NPAb) and glycoprotein GZ (G,Ab), were developed using monoclonal antibody L133, L13r3, LV48A and LVZB28B NPAb and GZAb in 291 serum samples from 65 patientswith kemorrkagic fever with renal syudrome (HFRS) were detfrmlned by these methods. The positive rates or NPAb were 90N on day 2-3 and 100 % on day 8-9 arter onset of disease, respectively.NPAb titers Increased during fever period and reached Peak levels during kypotensive and oliguric periods of HFRS. It was suggested that NPAb might be an important component Involved in the immunopathogenlc lin'alrmeut of HFRS and the detection of NPAb might be useful for the early diagnosis or HFRS. The I,osltlve rates and titers of GZAh were very low during the rirst three periods,namely rever, hypoteuslve and ollgurlc periods, and reached high levels during the convalescent period. GRAb titers were negatively related to the I,rotelnurla levels during the course of HFRS. It wasIndicated that GZAb might be the main component or neutralizing autlhodles to Hantaan virus Infection and the efrlclent production or GZAb was a good marker ror predicting the recovery and betterprognosis of HFRS.

A protective human antibody against respiratory syncytial virus by targeting a prefusion epitope across sites IV and V of the viral fusion glycoprotein

Respiratory syncytial virus(RSV)is one of the leading pathogens that cause lower respiratory tract infections in infants and the elderly.Passive immunoprophylaxis with monoclonal antibody(mAb)has been approved to prevent morbidity and mortality from RSV infection in infants.Here we report the isolation of two neutralizing mAbs against RSV from convalescent children by prefusion form of fusion(F)glycoprotein as bait.One mAb RV11 exhibited good potency in neutralization of RSV strains from both A and B subtypes in cell-based assay,and protected mice from RSV infection in vivo.An RV11 escape mutant was identified,which contains an S443P mutation in F protein.Crystal structure showed the RV11 bound to a conserved prefusion epitope across the antigenic sites IV and V of the F glycoprotein.RV11 showed a strong synergistic effect when combined with two RSV antivirals,an F-targeting small molecular inhibitor ziresovir and a siteØneutralizing mAb D25(the parental mAb for nirsevimab).The study extended our knowledge to the neutralizing and protective epitopes of RSV,and the mAb RV11 deserves further development for clinical translation.

The Paper Symposium on PLC VIRAL HEPATITIS（HBV AND HCV）BACKGROUND IN CHINESE PATIENTS WITH HEPATOCELLULAR CARCINOMA

Antibody to hepatitis C virus (AntiHCV) was detected using antiHCV EIA (Abbott Kit) in the sera of Chinese patients with hepatocellular carcinoma (HCC), acute hepatitis, chronic hepatitis and blood donors, the positive rates being 10.4% (61/586),11. 8% (10/85),19.2% (44/229), ana 1. 9% (3/160) respectively. HBV DNA was detected by polymerase chain reaction (PCR) in sera from 61 HCC patients with positive antiHCV, the positive rate for HBV DNA being 55.7% (34/61),which was lower than those with negative antiHCV (78.7%) , 413/525). These results indicate that in Chuia the role of HBV infection in the causation of HCC seems to be more important than that of HCV infection.

Evaluate the prevalence and trend of hepatitis B and hepatitis C in Nahavand: west of Iran, 2013–2017

Viral hepatitis is a global threat to public health and one of the leading causes of death worldwide.Often,acute viral cases in children and adults are associated with viral hepatitis A,B,C,D and E,or co-infection with two types of hepatitis.Infection with these viruses is a global health problem and continuous efforts are in place to identify infected people through targeted screening,preventing new infections through vaccination,monitoring and treating people at risk for complications of all types of hepatitis.The aim of this study was to determine the evaluate the prevalence and trends of hepatitis B and C infection in the Nahavand city during 5 consecutive years(2013–2017).The total number of patients with hepatitis B and C was 141 persons from March 2013 to March 2017,of these,101 had hepatitis B,and 40 had hepatitis C.The prevalence of hepatitis B and C was higher in men than women.The percentage frequency hepatitis B in the city in the last five years was 0.05 percent.11 cases(10.89%)pregnant women and Six cases(5.9%)receiving blood(blood transfusions)in Hepatitis B was observed.the prevalence of hepatitis C was 0.2%at the end of 2017.The study on the cause of hepatitis C in Nahavand has shown that 21(52.5%)of the total of 40 people were infected with addiction.The interesting point in this report is that according to reports from viral hepatitis testing questionnaires,24 of 101 people with type B hepatitis have 23.7%of people with a history of complete vaccination of hepatitis B and one person(0.9%)had incomplete vaccination.A significant relationship was found between the level of education and the prevalence of hepatitis(P=0.005).

Both structure and function of human monoclonal antibodies contribute to enhancement of Zika virus infectivity in vitro

Dear Editor,Antibody-dependent enhancement(ADE)has long been recognized for dengue virus(DENV)in vitro and in vivo.It is now clear that antibodies to DENV can also enhance Zika virus(ZIKV)infection in vitro,and vice versa(Dejnirattisai et al.,2016;Stettler et al.,2016).The characteristics of enhancing antibodies,however,remain elusive.Some have suggested that non-neutralizing antibodies or antibodies recognizing specific antigenic sites are

Neutralization activity of influenza A virus humanized antibodies against new subtypes of influenza viruses

Antibodies are ideal for controlling the influenza A virus,but their effect on newly emerging strains is unclear.Here,we assessed the neutralization activity of the humanized monoclonal antibodies(mAbs)F10,H98 and H40 against circulating influenza viruses(H5N1,H1N1,H3N2 and H7N7 and new subtypes viruses H5N6 and H7N9).The results showed that all the three humanized mAbs(F10,H98 and H40)displayed different degrees of virus neutralization activities when encountered with different subtypes of influenza viruses.Remarkably,the humanized monoclonal antibody F10 produced higher and broader neutralization titers(range 25–1.56μg/ml)than those of the other two humanized mAbs(H98(range 50–3.12μg/ml),H40(range 50–5.56μg/ml))to against the viruses H5N1,H1N1,H3N2,H7N7,H5N6 and H7N9.This mAb may represent a new class of heterosubtypic neutralizing humanized mAb that could replace vaccines and chemical drugs.