Study on epidemiological prevalence and serological marker characteristics of hepatitis E infection / 中华检验医学杂志

Objective:This study aims to explore the prevalence of hepatitis E virus (HEV) infection in patients and the screening value of serological indicators for HEV infection patients.Methods:Retrospective analysis was conducted on 97 440 cases of anti-HEV IgM and IgG simultaneously tested in two Beijing hospitals from January 1, 2018 to August 31, 2023. Among them, there were 61 005 males and 36 435 females, with an average age of 51.65±13.05 years old. According to the positivity of anti HEV specific antibodies, they were divided into anti-HEV IgM positive group (3 588 cases), anti-HEV IgG positive group (18 083 cases), and anti-HEV antibody negative group (78 892 cases). Results of HEV RNA, liver function, AFP, PIVKA-Ⅱ and PT were collected, and their basic clinical information were recorded. The prevalence of HEV infection in patients, as well as the relationship between the positivity of anti-HEV specific antibodies and the patient′s age group, HEV RNA, and clinical characteristics were analyzed.Results:Among 97 440 patients who tested anti-HEV IgM and IgG simultaneously, the positivity rate of anti-HEV IgM was 3.68% (3 588/97 440), and was 18.56% for anti-HEV IgG (18 083/97 440). The overall positivity rates of anti-HEV IgM in two Beijing hospitals from 2018 to 2023 were 2.51%, 2.53%, 3.02%, 4.59%, 5.72%, and 4.26% ( χ2=1 401.73, P<0.001), while the positivity rates of anti-HEV IgG were 12.56%, 12.32%, 12.85%, 22.65%, 27.42%, and 26.66% ( χ2=1 058.29, P<0.001). These rates showed a gradual increase until 2023 when a decline was observed. The positivity rates of anti-HEV IgM (2.28%, 3.60%, 4.47%) ( χ2=89.62, P<0.001) and IgG (4.71%, 17.86%, 25.94%) ( χ2=2 017.32, P<0.001) increased with age in patients who aged 1-30, >30-60, and over 60 years old. The age and ALB values of patients in the anti-HEV IgM positive group were lower than the IgG-positive group, while the proportion of males, TBIL, ALT, AFP and PT values were higher than the IgG-positive group, and the differences were statistically significance ( P<0.05). Furthermore, patients in both the anti-HEV IgM and IgG positive groups had higher age, male proportion, TBIL, ALT, AFP, PIVKA-Ⅱ, and PT values than the anti-HEV negative group. Additionally, both groups had lower ALB values than the anti-HEV negative group, all of which were statistically significant ( P<0.05). 2 162 HEV infected patients were grouped based on HEV RNA positivity. The proportion of anti-HEV IgM single positive, IgG single positive, IgM+IgG double positive, and antibody negative patients in the HEV RNA positive group were 5.42% (18/332), 3.62% (12/332), 90.36% (300/332), and 0.60% (2/332), respectively. Among them, the proportion of anti-HEV IgM+IgG double positive patients in the HEV RNA positive group was higher than that in the HEV RNA negative group ( χ2=302.87, P<0.001), while the proportion of anti-HEV IgG single positive ( χ2=174.36, P<0.001) and anti-HEV antibody negative patients ( χ2=59.28, P<0.001) were lower than that in the HEV RNA negative group, both of which were statistically significant ( P<0.001). In addition, the positive rates of HEV RNA in anti-HEV IgM positive, IgG positive, and antibody negative patients were 29.23% (318/1 088), 17.59% (312/1 774), and 0.65% (2/306), respectively. Conclusion:The HEV infection rate among patients declined in 2023. HEV infection is age-related, with older individuals being more susceptible. Abnormal liver function and jaundice were commonly observed during HEV infection. It is crucial to note that the absence of anti-HEV specific antibodies cannot rule out HEV infection; therefore, additional testing for HEV RNA and/or HEV Ag is necessary for accurate diagnosis.

A multi-center performance evaluation of different hepatitis C virus core antigen assays for clinical infection screening / 中华检验医学杂志

Objective:We conducted a real-world multi-center clinical study with a large sample size to comprehensively evaluate the performance of three commercial hepatitis C virus (HCV) core antigen assays. The study aimed to evaluate the performance for their use in HCV infection screening, and to provide clues for further improving the sensitivity and specificity of the assays.Methods:Key performance indicators including the lower limit of detection (LOD), diagnostic sensitivity, and specificity of three HCV antigen assays (the Architect, Laibo, and ChemClin HCV core antigen assays) were evaluated using commercial seroconversion panels reflecting early HCV infection and clinical routine serum samples of outpatients and inpatients from 3 tertiary hospitals from January 2018 to April 2022. Factors that affect the performance indicators were further investigated.Results:The window period for detecting HCV infection with the three antigen assays was equal to or slightly longer than that of the RNA assay, but all are shorter than that of the anti-HCV assay. There was a good linear positive correlation between HCV core antigen and HCV RNA levels in treatment naive patients with hepatitis C ( r=0.90, P<0.01). For the most common genotype 1b strain in China, the LOD of the three HCV assays were equivalent to 531 IU/ml (Architect), 3,698 IU/mL (Laibo), and 4,624 IU/mL (ChemClin) HCV RNA, respectively. Due to the skewed distribution of HCV RNA levels in treatment-naive hepatitis C patients, more than 95% of the patients had viral loads higher than 6 166 IU/ml. Therefore, the three HCV antigens assays still maintained a satisfactory diagnostic sensitivity (94.33%-99.40%). Among 54 immunodeficient patients (leukemia patients) with HCV infection, 9% (5/54) had negative anti-HCV results, while the HCV antigen assays found all these infectors. Through further experiments, we revealed the amino acid polymorphism in the core region of genotype 3 strain impaired the sensitivity of all three HCV antigen assays. In addition, the sensitivity of the two domestic assays was impaired by anti-HCV antibodies in the serum. The specificity of HCV antigen assays for diagnosing hepatitis C is 99.94% to 99.98%. The rheumatoid factors, autoantibodies, and other unknown interference substances can lead to a small number of low level, "false positive" antigen results. Conclusions:HCV core antigen assay may be used as a satisfactory approach of infection screening, especially for the immunodeficient patents. However, the sensitivity and specificity of the assays are influenced by multiple factors, which should be further improved.

Clinical significance of hepatitis B virus DNA detection in screening patients with hepatitis B / 中华检验医学杂志

Objective:To explore the clinical significance of hepatitis B virus (HBV) DNA detection in screening patients with hepatitis B.Methods:Clinical data of 682 331 hepatitis B patients were retrospectively analyzed. The HBV DNA of these patients was detected in the Fifth Medical Center of the PLA General Hospital from January 2017 to December 2021, there were 481 159 males and 201 172 females in this cohort, the average age was (41.34±16.13) years. Patients were divided into HBV DNA positive group (219 879 cases) and HBV DNA negative group (462 452 cases). Clinical characteristics, data of five serologic markers of hepatitis B and hepatitis B surface antigen quantification (HBsAg-QN), liver function, alpha fetoprotein (AFP) and prothrombin time (PT) results were collected and analyzed and compared between the two groups.Results:The positive rate of HBV DNA was 32.22% (219 879/682 331) in this cohort. Among the different age groups, the positive rate of HBV DNA was the highest (40.34%, 128 038/317 380) in young people aged 18-44 years. The proportion of patients was lower among aged <1, 45-59 and ≥60 years patients in HBV DNA positive group than that in HBV DNA negative group, while the proportion of patients was higher among aged 1-17 and 18-44 years patients in HBV DNA positive group than that in HBV DNA negative group (all P<0.001). Among 2 291 <1-year-old infants tested for HBV DNA, 71 infants were HBV DNA positive. The positive rates of HBV DNA from 2017 to 2021 were 4.86% (27/556), 3.68% (14/380), 3.47% (17/490), 1.55% (6/386) and 1.46% (7/479) respectively, showing a downward trend year by year. The positive rate of HBV DNA in acute hepatitis B (AHB) patients was the highest (49.88%, 208/417) among 680 040 patients with hepatitis B. The proportion of AHB patients (0.09%, 208/219 808) and chronic hepatitis B (80.44%, 176 806/219 808) in HBV DNA positive group was higher than that in HBV DNA negative group [0.05% (209/460 232) and 65.45% (301, 216/460 232)], while the proportion of patients with HBV-related liver cirrhosis (11.28%, 24 793/219 808), HBV-related liver cancer (6.72%, 14 775/219 808), liver cancer surgery (1.39%, 3 055/219 808) and liver transplantation (0.08%, 171/219 808) were lower than that in HBV DNA negative group [22.99% (105 813/460 232), 7.25% (33 385/460 232), 3.50% (16 129/460 232) and 0.76% (3 480/460 232)] (all P<0.001). At the same time, positive rate of hepatitis B surface antigen (HbsAg), HBsAg-QN, hepatitis B e antigen (HbeAg), level of total bilirubin, total bilirubin, AFP and PT were higher in HBV DNA positive group than those in HBV DNA negative group, while the age, male ratio and albumin results in HBV DNA positive group were lower than those in HBV DNA negative group (all P<0.01). The HBV DNA loads were higher in HBsAg positive group, hepatitis B surface antibody positive group and HBeAg positive group than those in respective negative groups, while the HBV DNA loads were lower in hepatitis B e antibody positive group and hepatitis B core antibody positive group than those in respective negative groups (all P<0.001). Conclusions:The mother to child transmission rate of<1-year-old infants decreases year by year. HBV DNA is an important factor for the progression of hepatitis B disease. HBV DNA positive hepatitis B patients with higher HBsAg-QN values are more likely to have abnormal serum markers such as liver dysfunction. HBV DNA detection is therefore of clinical importance in screening patients with hepatitis B.

Emerging and comparative genomic analysis of a novel plasmid carrying blaKPC-2 in Citrobacter freundii / 中华预防医学杂志

Objective: To explore the drug resistance mechanism and gene structure characteristics of a carbapenemase-producing novel incompatibility group plasmid pNY2385-KPC from Citrobacter freundii. Methods: A multi-drug resistant strain was obtained from urine samples of patients with fever in the emergency ward of Li Huili Hospital, Ningbo Medical Center. Bacterial species was preliminary identified and finally confirmed by 16S rRNA gene amplification and the average nucleotide identity alignment, respectively. The minimum inhibitory concentrations of the antimicrobial agents were determined by VITEK 2 Compact System. The complete genome sequence was obtained by "third-generation" sequencing methods, and then detailed annotation of gene function and comparative genomic analysis of plasmid structure were carried out by BLASTP/BLASTN, RefSeq, ConservedDomains, ResFinder, Isfinder, etc. Results: The pNY2385-KPC carried by citrobacter freundii NY2385 belonged a novel incompatibility group, and contained blaKPC-2 and conjugative transfer (type Ⅳ secretory system, T4SS) genes, which could induce conjugative transfer. A total of 15 plasmids of the same type as pNY2385-KPC were retrieved by NCBI, which were from Citrobacter freundii, and the rest were from Serratia marcescens, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Raoultella planticola and other bacteria, and were broad-host-range plasmids. The sequence comparative analysis of all 6 of the novel plasmid from Citrobacter freundii showed that the structure of the novel plasmid had certain conserved property, with Tn6296 variant structure carrying blaKPC-2, and plasmid pCF1807-3 had both repApNY2385-KPC and repAIncX8. Conclusion: The pNY2385-KPC type plasmids in Citrobacter freundii carried blaKPC-2 resistance gene, which were divided into two subtypes: repApNY2385-KPC single replicator and repApNY2385-KPC/repAIncX8 complex replicator, belonging to broad-host-range plasmids. And as a mobile genetic element, the plasmids promote the spread of blaKPC-2.

Emerging and comparative genomic analysis of a novel plasmid carrying blaKPC-2 in Citrobacter freundii / 中华预防医学杂志

Objective: To explore the drug resistance mechanism and gene structure characteristics of a carbapenemase-producing novel incompatibility group plasmid pNY2385-KPC from Citrobacter freundii. Methods: A multi-drug resistant strain was obtained from urine samples of patients with fever in the emergency ward of Li Huili Hospital, Ningbo Medical Center. Bacterial species was preliminary identified and finally confirmed by 16S rRNA gene amplification and the average nucleotide identity alignment, respectively. The minimum inhibitory concentrations of the antimicrobial agents were determined by VITEK 2 Compact System. The complete genome sequence was obtained by "third-generation" sequencing methods, and then detailed annotation of gene function and comparative genomic analysis of plasmid structure were carried out by BLASTP/BLASTN, RefSeq, ConservedDomains, ResFinder, Isfinder, etc. Results: The pNY2385-KPC carried by citrobacter freundii NY2385 belonged a novel incompatibility group, and contained blaKPC-2 and conjugative transfer (type Ⅳ secretory system, T4SS) genes, which could induce conjugative transfer. A total of 15 plasmids of the same type as pNY2385-KPC were retrieved by NCBI, which were from Citrobacter freundii, and the rest were from Serratia marcescens, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Raoultella planticola and other bacteria, and were broad-host-range plasmids. The sequence comparative analysis of all 6 of the novel plasmid from Citrobacter freundii showed that the structure of the novel plasmid had certain conserved property, with Tn6296 variant structure carrying blaKPC-2, and plasmid pCF1807-3 had both repApNY2385-KPC and repAIncX8. Conclusion: The pNY2385-KPC type plasmids in Citrobacter freundii carried blaKPC-2 resistance gene, which were divided into two subtypes: repApNY2385-KPC single replicator and repApNY2385-KPC/repAIncX8 complex replicator, belonging to broad-host-range plasmids. And as a mobile genetic element, the plasmids promote the spread of blaKPC-2.

Analysis of characteristics of drug resistance gene mutation in HBV RT region of hepatitis B infected patients / 中华预防医学杂志

Objective: This article investigated the clinical characteristics and distribution of drug resistance mutation sites in HBV RT region of hepatitis B infected patients. Methods: Retrospective analysis was made on 1 948 patients with HBV infection, who had been tested for NAs resistance mutation and had a medical history of NAs in the Laboratory Department of the Fifth Medical Center of the PLA General Hospital from January 2020 to December 2021. Basic clinical information and drug resistance related mutation information were recorded. Meanwhile, the serological index data of hepatitis B were collected. Drug resistance gene mutant group and non-mutated group were grouped according to whether the drug resistance genes had a mutation in HBV RT region, and the clinical characteristics and genotype distribution of the two groups were statistically analyzed. The pattern of drug resistance gene mutation, number of mutation sites, drug resistance type and mutation of NAs resistance-related sites were analyzed in 917 patients with drug resistance gene mutation in HBV RT region. χ2 Inspection was used for counting data. Meanwhile, two independent samples t-test and Wilcoxon rank sum test were used for measurement data. Results: Among the 1 948 patients with chronic HBV infection, 917 patients had drug resistance gene mutation in RT region (47.07%). The proportion of patients with acute hepatitis B and CHB in HBV RT resistance gene mutant group was lower than that in the non-mutated group, while the proportion of patients with HBV-related cirrhosis was higher than that in the non-mutated group, these differences were statistically significant. Compared with the non-mutated group in HBV RT region, the age, the positive rates of HBeAg and HBV DNA, and HBV DNA load of these patients were increased in drug resistance gene mutant group, these differences were statistically significant. Genotypes of patients in both groups were dominated by C, followed by B and D. The proportion of patients with genotype C in HBV RT drug resistance gene mutant group was higher than that of non-mutated group, the difference was statistically significant. There were 53 gene mutation patterns in 917 patients with drug resistance gene mutation in HBV RT region, and the main pattern was rtL180M+rtM204V+rtS202G (9.70%). The mutation sites were dominated by 3 (20.74%). There were 5 types of drug resistance, LAM+Ldt (21.25%) was the most. Among the 18 sites that were clearly associated with LAM, ADV, ETV and Ldt resistance in the HBV RT region, 14 sites were mutated, and the most common mutation sites were rtL180M, rtM204V, rtM204 and rtS202G. what's more, the proportion of patients with NAs drug resistance was LAM>Ldt>ETV>ADV. Conclusion: In order to prevent adverse consequences of this study such as disease recurrence or disease progression caused by HBV drug resistance, HBV infected patients, who have long-term use of NAs antiviral therapy, should monitor the level of HBV DNA and drug resistance genes in HBV RT region in order to optimize the treatment plan in time or guide individualized treatment.

Quantitative detection of serum procollagen III N-terminal peptide chemiluminescence enzyme immunoassay / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish chemiluminescence enzyme immunoassay (CLEIA) for quantitative detection of procollagen III N-terminal peptide (P III NP) in serum.</p><p><b>METHODS</b>A sandwich reaction was preformed with horseradish peroxidase labeled monoclonal antibody of P III NP as the catalytic enzyme and the luminol as the luminescence reagent. Several reactions liquid's concentration and reaction conditions were optimized. The method was evaluated in all aspects such as linear range, sensitivity, specificity, stability and so on. The CLEIA was compared with imported ELISA kits, by detecting clinical serum.</p><p><b>RESULTS</b>The linear range was 0.8-85 ng/ml. The detection limit was 0.5 ng/ml. Inter-assay and intra-assay RSD were both less than 10%. The recoveries of three different spiked concentration samples were 96.2%, 91.2% and 101.1%. After stored at 4 degrees C and 37 degrees C for 3, 5, 7 days, the analysis showed correlation coefficient higher than 0.99 and RSD lower than 6%. The detected results of clinical sera with CLEIA closely corresponded to those with imported ELISA.</p><p><b>CONCLUSION</b>Established CLEIA for quantity determination of serum P III NP has high accuracy, sensitivity and repeatability.</p>

Establishment of a quantitative detection method for Golgi protein73 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish enzyme-linked immunosorbent assay (ELISA) for quantitative detection of Golgi protein73 (GP73) in serum.</p><p><b>METHODS</b>A sandwich reaction was preformed with horseradish peroxidase labeled monoclonal antibody of GP73 as the catalytic enzyme. Several reactions liquid's concentration and reaction conditions were optimized. The method was evaluated in all aspects such as linear range, sensitivity, specificity, stability and so on.</p><p><b>RESULTS</b>The linear range was 25-500 ng/ml. The detection limit was 18.5 ng/ml. Inter-assay and intra-assay RSD were both less than 10%. The recoveries of three different spiked concentration samples were 95.3%, 92.6% and 103.7%. After stored at 4 degrees C and 37 degrees C for 3, 5, 7 days, the analysis showed correlation coefficient higher than 0.98 and RSD lower than 10%.</p><p><b>CONCLUSION</b>Established ELISA for quantity determination of serum GP73 has high accuracy, sensitivity and repeatability.</p>

Cloning and expressing of golgi protein73 gene fragment and preparation of monoclonal antibodies against the recombinant protein / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To clone and express human Golgi glycoprotein73 protein, and prepare the monoclonal antibody (mAb) against the protein.</p><p><b>METHODS</b>GP73 gene was amplified from HepG2 cells by RT-PCR, then ligated with pQE31 to form recombinant plasmid pQE-GP73 and transformed into E. coli BL21. The protein induced by IPTG was purified by 6 x His-tag and used to immunize the BALB/c mice. The specific monoclonal antibodies (mAbs) were prepared by the cell fusion technique. Western Blot was used to detect specificity of mAbs.</p><p><b>RESULTS</b>The prokaryotic plasmid expressing the recombinant protein was constructed, and the GP73 recombinant protein was expressed and purified. Five hybridoma cell lines that secreted anti-GP73 mAbs were obtained. 2 of 5 mAbs were the IgG1 subtype. Western Blot indicated the mAbs showed specific combination with GP73 protein.</p><p><b>CONCLUSION</b>The GP73 recombinant protein is highly purified and has strong antigenicity. The anti-GP73 mAbs were prepared successfully.</p>

Microplate chemiluminescence enzyme immunoassay for the quantitative analysis of tissue inhibitor of metalloproteinases I / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish microplate chemiluminescence enzyme immunoassay (CLEIA) for quantitative analysis of tissue inhibitor of metalloproteinases I (TIMP I) in human serum.</p><p><b>METHODS</b>A sandwich reaction was preformed with horseradish peroxidase(HRP) labeled monoclonal antibody of TIMP I as the catalytic enzyme and the H2O2-luminol as the luminescence reagent. Several physical and chemical parameters were studied and optimized such as immunoreaction conditions, the dilution ratio of TIMP I-HRP, luminescence reaction time and so on. In order to evaluate the method, recovery test, heat stabilization test and comparison test were carried out.</p><p><b>RESULTS</b>The linear range was 0. 2-12 ng/ml with r = 0.996. The detection limit was 0.12 ng/ml. Inter-assay and intra-assay RSD were both less than 10%. The recoveries of three different spiked concentration samples were 100.6%, 96.5% and 106.5%. After stored at 4 degrees C and 37 degrees C for 3, 5, 7 days, the analysis showed correlation coefficient higher than 0. 998 and RSD lower than 6%. The detected results with CLEIA closely corresponded to those with imported ELISA in 60 patients sera with liver fibrosis.</p><p><b>CONCLUSION</b>Established CLEIA for quantity determination of serum TIMP I has high accuracy, sensitivity and repeatability.</p>

Establishment of a detection method for hepatitis B virus large surface protein (HBV-lP) / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish enzyme-linked immunosorbent assay (ELISA) for detection of hepatitis B virus large surface protein(HBV-LP) in serum.</p><p><b>METHODS</b>A sandwich reaction was preformed with horseradish peroxidase labeled monoclonal antibody of HBV-LP as the catalytic enzyme. Several reactions liquid's concentration and reaction conditions were optimized. The method was evaluated in all aspects such as sensitivity, specificity, stability and so on.</p><p><b>RESULTS</b>The detection limit was 5 ng/ml. Interassay and intra-assay RSD were both less than 10%. After stored at 4 degrees C and 37 degrees C for 3, 5, 7 days, the analysis showed correlation coefficient higher than 0.98 and RSD lower than 10%.</p><p><b>CONCLUSION</b>Established ELISA for determination of serum HBV-LP has high sensitivity and repeatability. Enzyme-linked immunosorbent assay;</p>

Serum GP73 were increased in patients with fatty liver disease / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To explore the levels of serum GP73 in patients with fatty liver disease.</p><p><b>METHODS</b>The sera GP73 were determined by ELISA in 178 patients with fatty liver disease and 100 healthy controls.</p><p><b>RESULTS</b>Serum GP73 levels were significantly increased in patients with various fatty liver diseases(70.62 +/- 60.60 ng/ml), compared with those of control population (35.61 +/- 12.22 ng/ml). In patients with alcoholic fatty liver disease, acute liver injury, chronic hepatitis B, and non-alcoholic fatty liver disease, their serum GP73 concentration were 81.86 +/- 47.82 ng/ml, 82.77 +/- 77.73 ng/ml, 63.84 +/- 50.62 ng/ml, and 65.75 +/- 62.20 ng/ml, respectively. But no significant difference was found between these groups (P > 0.05). In 68 patients with F > or = 1.0 (71.46 +/- 66.48 ng/ml), 75 patients with F> or = 2.0 (69.58 +/- 62.31 ng/ml), and 34 patients with F3-F4 (71.65 +/- 43.89 ng/ml), there were also no marked differences was observed between these fatty groups (F = 0.02, P = 0.98).</p><p><b>CONCLUSION</b>Serum GP73 levels were increased in patients with different liver diseases, but its concentrations were seems not related with degree of fatty injury.</p>

Cloning and expressing of tissue inhibitor of metalloproteinases I gene fragment and preparation of monoclonal antibodies against the recombinant protein / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To prepare the monoclonal antibody (mAb) against tissue inhibitor of metalloproteinases I (TIMP-I) fusion protein.</p><p><b>METHODS</b>TIMP-I gene was amplified from fibrotic human liver tissue by RT-PCR, then ligated with pQE31 to form recombinant plasmid pQE-TIMP-I and transformed into E. coli BL21. The protein induced by IPTG was purified by 6 x His-tag and used to immunize the BALB/c mice. The specific monoclonal antibodies (mAbs) were prepared by the cell fusion technique. Western Blot were used to detect specificity of mAbs.</p><p><b>RESULTS</b>The prokaryotic plasmid expressing the recombinant protein was constructed, and the TIMP-I recombinant protein was expressed and purified. Four hybridoma cell lines that secreted anti-TIMP-I mAbs were obtained. 3 of 4 mAbs were the IgG1 subtype. Western Blot indicated the mAbs showed specific combination with TIMP-I protein.</p><p><b>CONCLUSION</b>The TIMP-I recombinant protein is highly purified and has strong antigenicity. The anti- TIMP-I mAbs were prepared successfully.</p>

Establishment of a purificatory method for alpha-fetoprotein variant by affinity adsorption / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish a purificatory method of alpha-fetoprotein variant (AFP-L3) based on microspincolumn with lens culinaris agglutinin (LCA).</p><p><b>METHODS</b>LCA was isolated by ammonium sulfate precipitation method from lens culinaris. AFP-L3 affinity adsorption microspincolumns which were made from LCA coupled with activated Sepharose 4B were prepared. By adding into the centrifuge column, serum was absorbed and eluted to purify AFP-L3. The results of purified AFP-L3 detection of 10 cases AFP positive sera by electro-chemiluminescence immunoassay were compared with traditional crossed affinity immunoelectrophoresis.</p><p><b>RESULTS</b>8 of 10 cases AFP-L3 concentration were greater than 5 ng/ml in purified sera. Six cases show positive reaction in affinity immune cross electrophoresis experiment.</p><p><b>CONCLUSION</b>Successfully established purification method of AFP-L3 by affinity absorption based on microspincolumn. The method was more conducive to clinical laboratory applications due to its high sensitive and easy operation.</p>

The investigantion of comparative experiments for different clinical laboratory instruments / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To estimate the consistency of two VITROS 3600 chemiluminescent analyzers according to the requirement of ISO15189.</p><p><b>METHODS</b>Verification tests were made for precision and accuracy of anti-HCV in two instruments. While 40 serum samples including Anti-HCV negative (10 cases) , positive (10 cases) , and weakly positive (20 cases). and the test results were statistical analised.</p><p><b>RESULTS</b>Two instruments negative and positive control samples intra-batch precision and coefficients of variation were 5% , 4% and 7. 14% , 7. 23% , inter-batch precision and coefficients of variation were 9. 47% , 7. 7% and 8.04%, 7. 6%, are less than requirement CV (15%) by ISO15189. The accuracy of two instrument were 100% , The test results of the control samples showed no significant difference (P < 0. 05). The correlation analysis of the test results of clinical samples R2 =0. 9984, with good consistency.</p><p><b>CONCLUSION</b>Test results of two Vitros 3600 has good consistency and comparability.</p>

Comparison of two different methods to detect HIV antibodies / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Evaluated the chemiluminescence and enzyme-linked immunosorbent assay (ELISA) to detect HIV antibodies, and compared the results, to provide a reference for the selection and clinical application of HIV screening.</p><p><b>METHODS</b>3000 cases of our hospital patients were measured by enzyme-linked immunosorbent assay and chemiluminescence immunoassay, using comfirmming experimental results as gold standards. Comparing sensitivity, specificity and other Indicators.</p><p><b>RESULTS</b>In the diagnosis of HIV infection, enzyme-linked immunosorbent assay and chemiluminescence immunoassay had no significant difference. The positive rate of enzyme-linked immunosorbent assay was 0.93%, while the sensitivity and specificity were 89.66%, 99.93%, the positive rate of chemiluminescence immunoassay was 1.03%, while the sensitivity and specificity were 100%, 99.93%, respectively.</p><p><b>CONCLUSION</b>Both methods are suitable for screening of HIV, having high specificity, and chemiluminescence has greater sensitivity than ELISA.</p>

Establishment of confirmatory test for suspicious hepatitis B surface antigen positive samples / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Establish a confirmatory test based on ELISA, and use to verify the authenticity of HBsAg weak positive samples, pick and get rid of the false result, and avoid the mistake diagnosis.</p><p><b>METHOD</b>The particles (reagent A) coated by streptavidin and biotinylated HBsAb (reagent B) were mixed in different proportions, then neutralized with serum whose the COI of HBsAg > 20 by ELISA in order to identify the activity of HBsAb in confirmatory reagent. 30 pieces of HBsAg weak positive serum neutralized with the confirmatory reagent, the serum were considered to be positive if rate of decline of HBsAg COI > 50%. The results were compared to Roche confirmatory Kit.</p><p><b>RESULT</b>Confirmatory reagent was able to neutralized with HBsAg. 24 of 30 pieces of HBsAg weak positive samples were judged to be positive, while 6 poeces were negative. The ELISA comfirm method is fully consistent with Roche confirmatory Kit.</p><p><b>CONCLUSION</b>The ELISA confirmatory test for suspicious HBsAg positive samples is a simple, accurate and low cost initial validation method, After further clinical trials, should be widely applied.</p>

Analysis of hemagglutination inhibition antibody level in patients with influenza A H1N1 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand the hemagglutination inhibition antibody level in patients with influenza A H1N1.</p><p><b>METHODS</b>Sera from 28 patients with influenza A H1N1 at different time points after illness onset were collected and measured by hemagglutination inhibition assay.</p><p><b>RESULTS</b>The serum hemagglutination inhibition antibody titers at 1, 5, 15, 22, 37, 49 and 58 days after illness onset were 5.36, 9.39, 39.02, 57.99, 137.92, 55.19 and 57.99 respectively. The top geometric mean titer of hemagglutination inhibition antibody was 148.55. The antibody seroconversion rate and seroprotection rate were occurred in 96.4% (27/28) of patients.</p><p><b>CONCLUSION</b>The patients with influenza A H1N1 have effective immune response.</p>

Quantitative analyses of intrahepatic HBV cccDNA and serum HBsAg in 54 patients with chronic hepatitis B / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To quantitatively detect intrahepatic HBV covalently closed circular DNA (cccDNA) and serum HBsAg; and to analyze the relationship between the two parameters and with serum HBV DNA level.</p><p><b>METHODS</b>Intrahepatic cccDNA (copies/cell) was quantitated by plasmid-safe ATP-dependent Danes (PSAD) digestion in combination with rolling circle amplification and gap-spanning selective real-time PCR assay using formalin fixed paraffin-embedded liver biopsy samples. HBsAg was measured by chemiluminescence's reagent manufactured by Abbott Company using sera sampled at time-point of liver biopsy.</p><p><b>RESULTS</b>Intrahepatic cccDNA level was positively correlated with serum HBsAg level (r = 0.459, P < 0.001), but not correlated with serum HBV DNA level. Serum HBsAg level was positively correlated with serum HBV DNA level (r = 0.328, P = 0.015), and reversely correlated with HBV replicative efficiency defined as the ratio of serum HBV DNA to cccDNA (r = -0.373, P = 0.005).</p><p><b>CONCLUSION</b>In patients with chronic hepatitis B, intrahepatic cccDNA level is correlated with serum HBsAg level. The two parameters combined with serum HBV DNA may comprehensively reflect HBV replication activity and help evaluation of antiviral therapeutic efficacy.</p>

The establishment of real time fluorescent PCR detecting method and preliminary application on pathogenesis of HFMD / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish the real-time fluorescent PCR method for detecting enterovirus, enterovirus 71 and Coxsackievirus A 16 nucleic acid.</p><p><b>METHODS</b>Primers and MGB probe were chosen for virus gene. The samples of 38 HFMD patients were analyzed by TaqMan-MGB PCR technique on a fluorescence real-time PCR instrument,and the results were compared with those by conventional RT-PCR.</p><p><b>RESULTS</b>The real-time fluorescent PCR positive rates of EV, EV71 and Cox A16 were 73.7%, 60.5%, 13.2%; the conventional RT-PCR were 71.1%, 55.3%, 13.2%. There were no significant differences between the two methods.</p><p><b>CONCLUSION</b>The real-time fluorescent PCR detecting method of EV, EV71 and Cox A16 nucleic acid have been established successfully.</p>