• Title/Summary/Keyword: sensitivity and specificity of ELISA

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Circulating Levels of Adipocytokines as Potential Biomarkers for Early Detection of Colorectal Carcinoma in Egyptian Patients

  • Zekri, Abdel-Rahman N;Bakr, Yasser Mabrouk;Ezzat, Maali Mohamed;Zakaria, Mohamed Serag Eldeen;Elbaz, Tamer Mahmoud
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.16
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    • pp.6923-6928
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    • 2015
  • Background: Early detection of various kinds of cancers nowadays is needed including colorectal cancer due to the highly significant effects in improving cancer treatment. The aim of this study was to evaluate the potential value of adiponectin, visfatin and resistin as early biomarkers for colorectal cancer patients. Materials and Methods: Serum levels of adiponectin, visfatin and resistin were measured by a sandwich-enzyme-linked (ELISA) assay technique in 114 serum samples comprising 34 patients with colorectal cancer (CRC), 27 with colonic polyps (CP), 24 with inflammatory bowel disease (IBD) and 29 healthy controls. The diagnostic accuracy of each serum marker was evaluated using receiver-operating characteristic (ROC) curve analysis. Results: The mean concentration of adiponectin was significantly higher in CRC and CP groups than IBD and control groups (P-value <0.05). Also the mean concentration of serum resistin was significantly elevated in the IBD and control groups compared to CRC and CP groups (P-value = 0.014). However, no significant difference was noted in patients of the CRC and CP groups. On the other hand, the mean concentration of visfatin was significantly elevated in CRC and control groups compared to CP and IBD groups (P-value = 0.03). ROC analysis curves for the studied markers revealed that between CRC and IBD groups serum level of adiponectin had a sensitivity of 76.7% and a specificity of 76% at a cut off value of 3940, +LR being 3.2 and -LR 0.31 with AUC 0.852, while serum level of adiponectin between CP and IBD had a sensitivity of 77.8% and a specificity of 75% at a cut off value of 3300, with +LR=3.11 and -LR = 0.3 with AUC 0.852. On the other hand the serum level of visfatin between CRC and CP groups had a sensitivity of 65.5% and a specificity of 66.7 at a cut off value of 2.4, +LR being 1.67 and -LR 0.52 with AUC 0.698. Also the serum level of resistin had a sensitivity of 62.5% and a specificity of 70.3% at a cut off value of 24500, with +LR=2.1 and -LR = 0.53 with AUC 0.685 between control and other groups. On the other hand by comparing control vs CP groups resistin had a sensitivity of 81.8% and a specificity of 70.8% at a cut off value of 17700, with +LR=2.8 and -LR = 0.26 with AUC 0.763 while visfatin had a sensitivity of 68.2% and a specificity of 70.8% at a cut off value of 2.7, with +LR=2.34 and -LR = 0.0.45 with AUC 0.812. Conclusions: These findings support potential roles of adiponectin, visfatin and resistin in early detection of CRC and discrimination of different groups of CRC, CP or IBD patients from normal healthy individuals.

Expression of Hepatitis B Virus S Gene in Pichia pastoris and Application of the Product for Detection of Anti-HBs Antibody

  • Hu, Bo;Liang, Minjian;Hong, Guoqiang;Li, Zhaoxia;Zhu, Zhenyu;Li, Lin
    • BMB Reports
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    • v.38 no.6
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    • pp.683-689
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    • 2005
  • Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying ahexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5% of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100% with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent for HBsAb detection prepared by Pichia pastoris-derived S protein showed high sensitivity and specificity for detection of HBsAb standard. And a good correlation was obtained between the reagent produced by recombinant S protein and commercial kit produced by blood-origin HBsAg in random samples.

Clinical Impact and Reliability of Carbonic Anhydrase XII in the Differentiation of Malignant and Tuberculous Pleural Effusions

  • Liu, Yun-Long;Jing, Li-Ling;Guo, Qi-Sen
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.351-354
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    • 2013
  • Objective: To assess the practical utility of pleural fluid carbonic anhydrase XII (CAXII) quantification for differential diagnosis of effusions. Materials and Methods: Fluid was collected prospectively from fifty patients presenting with lymphocytic pleural effusions for investigation and CAXII was quantified by ELISA. Results: Pleural fluid CAXII concentrations were significantly higher in lung cancer patients (n=30) than in tuberculous controls (n=20). The sensitivity and specificity of this biomarker were 60%and 75%, respectively. CAXII measurement was not inferior to cytological examination in the diagnosis and exclusion of pleural effusions from lung cancer patitents (sensitivity 60% vs. 57%; specificity 75% vs. 100%; positive predictive value 77%; negative predictive value 54%). In patients with negative cytology, it offered a sensitivity of 54%. Conclusions: Pleural fluid CAXII is elevated in pleural effusions from lung cancer patients. Measurement of CAXII may be used in the future as a valuable adjunct to cytology in the diagnostic assessment of patients with pleural effusions related to lung cancer, especially when cytological examination is inconclusive.

Diagnostic Value of Fecal Calprotectin as a Screening Biomarker for Gastrointestinal Malignancies

  • Khoshbaten, Manouchehr;Pishahang, Parinaz;Nouri, Mohammad;Lashkari, Alireza;Alizadeh, Mahasti;Rostami-Nejad, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.4
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    • pp.1667-1670
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    • 2014
  • Background: Calprotectin in feces seems to be a more sensitive marker for gastrointestinal (GI) cancers than fecal occult blood, but its specificity may be too low for screening average risk populations. This study aims at evaluating the diagnostic value of fecal calprotectin as a screening biomarker for GI malignancies. Materials and Methods: In a case-control study, 100 patients with GI malignancies (50 patients with colorectal cancer and 50 patients with gastric cancer) and 50 controls were recruited in Tabriz Imam Reza and Sina hospitals during a 24-month period. One to two weeks after the last endoscopy/colonoscopy, fecal specimens were collected by the patients and examined by ELISA method for quantitative measurement of calprotectin content. The results were compared between the three groups. Results: The mean fecal calprotectin level was $109.1{\pm}105.3$ (2.3-454.3, median:74), $241.1{\pm}205.2$ (3.4-610.0, median:19.3) and $45.9{\pm}55.1{\mu}g/g$ (1.3-257.1, median:19.3) in gastric cancer, colorectal cancer and control group, respectively, the differences being significant (p<0.001) and remaining after adjustment for age. The optimal cut-off point for fecal calprotectin was ${\geq}75.8{\mu}g/g$ for distinguishing colorectal cancer from normal cases (sensitivity and specificity of 80% and 84%, respectively). This value was ${\geq}41.9{\mu}g/g$ for distinguishing gastric cancer from normal cases (sensitivity and specificity of 62%). Conclusions: Our results revealed that fecal calprotectin might be a useful and non-invasive biomarker for distinguishing colorectal cancer from non-malignant GI conditions. However, due to low sensitivity and specificity, this biomarker may not help physicians distinguishing gastric cancer cases from healthy subjects.

Establishment and application of a solid-phase blocking ELISA method for detection of antibodies against classical swine fever virus

  • Cao, Yuying;Yuan, Li;Yang, Shunli;Shang, Youjun;Yang, Bin;Jing, Zhizhong;Guo, Huichen;Yin, Shuanghui
    • Journal of Veterinary Science
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    • v.23 no.5
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    • pp.32.1-32.11
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    • 2022
  • Background: Classical swine fever (CSF) is a severe infectious disease of pigs that causes significant economic losses to the swine industry. Objectives: This study developed a solid-phase blocking enzyme-linked immunosorbent assay (spbELISA) method for the specific detection of antibodies against the CSF virus (CSFV) in porcine serum samples. Methods: A spbELISA method was developed based on the recombinant E2 expressed in Escherichia coli. The specificity of this established spbELISA method was evaluated using reference serum samples positive for antibodies against other common infectious diseases. The stability and sensitivity were evaluated using an accelerated thermostability test. Results: The spbELISA successfully detected the antibody levels in swine vaccinated with the C-strain of CSFV. In addition, the detection ability of spbELISA for CSFV antibodies was compared with that of other commercial ELISA kits and validated using an indirect immunofluorescence assay. The results suggested that the spbELISA provides an alternative, stable, and rapid serological detection method suitable for the large-scale screening of CSFV serum antibodies. Conclusions: The spbELISA has practical applications in assessing the vaccination status of large pig herds.

A sero-surveillance of Brucella spp. antibodies and individual risk factors of infection in cattle in Bangladesh

  • Ahasan, Shamim;Rahman, Siddiqur;Song, Hee-Jong
    • Korean Journal of Veterinary Service
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    • v.33 no.2
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    • pp.121-128
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    • 2010
  • Brucellosis is a serious zoonosis, recognized worldwide. It primarily affects animals, which act as reservoirs for human infection as well as being of economic significance to the agri-food industry. Bangladesh has been reported as an endemic area for brucellosis. So a cross sectional study was conducted to determine the seroprevalence and potential risk factors of brucellosis in cattle in Dinajpur and Mymensingh districts of Bangladesh. A total of 182 cattle were examined by Rose Bengal Plate Test (RBPT) between September 2008 and October 2009. Then Positive, doubtful, and negative samples were further confirmed with slow agglutination test (SAT) and both indirect and competitive enzyme linked immunosorbent assay (iELISA and cELISA). A questionnaire was used to collect epidemiological information of the animals. The overall animal-level prevalence was 3.30%. Brucellosis seroprevalence was higher (4.76% by cELISA) in cattle above 48 months than those under 48 months. Female showed higher seroprevalence (10.67%) than male (6.25%). Higher seroprevalence was also found in cattle bred naturally (20.0%) than artificially (8.77%) and cattle that aborted or with previous abortion record (22.22%) showed higher seroprevalence than non-aborted (7.69%). The sensitivity of RBT and SAT was found 100% as compared to cELISA standard test, whereas specificity of RBT (95.35%) was higher than that of SAT (94.32%).

Serodiagnosis of Echinococcosis by ELISA Using Cystic Fluid from Uzbekistan Sheep

  • Jin, Yan;Anvarov, Khikmat;Khajibaev, Abdukhakim;Hong, Samin;Hong, Sung-Tae
    • Parasites, Hosts and Diseases
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    • v.51 no.3
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    • pp.313-317
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    • 2013
  • According to increase of travel, the cases of imported echinococcosis have been increasing in Korea. The present study was undertaken to develop a serodiagnostic system for echinococcosis in Korea. For diagnosis of echinococcosis, the fluid of Echinococcus granulosus hydatid cysts was collected from naturally infected sheep in Uzbekistan. Also serum samples of infected patients who were surgically confirmed were collected in a hospital in Tashkent, Uzbekistan. According to the absorbance of 59 echinococcosis positive and 39 negative control serum samples, the cut-off value was determined as 0.27. The sensitivity and specificity of ELISA with hydatid fluid antigen were 91.5% and 96%, respectively. The antigen cross-reacted with the serum of some cysticercosis or clonorchiasis patients. However, immunoblot analysis on the cystic fluid recognized antigenic proteins of 7-, 16-, and 24-kDa bands in their dominant protein quantity and strong blotting reactivity. In conclusion, the present ELISA system using hydatid cyst fluid antigen from Uzbekistan sheep is sensitive and specific for diagnosis of echinococcosis cases.

Diagnosis of Cylindrocarpon destructans Using Enzyme-Linked Immunosorbent Assay

  • Li, Taiying;Ji, Sungyeon;Jung, Boknam;Kim, Bo Yeon;Lee, Kwang Sik;Seo, Mun Won;Lee, Sung Woo;Lee, Jungkwan;Lee, Seung-Ho
    • Research in Plant Disease
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    • v.25 no.3
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    • pp.131-135
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    • 2019
  • Cylindrocarpon destructans causes ginseng root rot and produces radicicol that has an antifungal effect. In this study, we developed a method to detect this fungus using enzyme-linked immunosorbent assay (ELISA). Secreted proteins of C. destructans were used as antigens to obtain C. destructans-specific IgG from mouse. Out of 318 monoclonal antibodies generated from mouse, two antibodies (Cd7-2-2 and Cd7-2-10) showed highest specificity and sensitivity. Indirect ELISA using both antigens successfully detected C. destructans in soils, but direct ELISA using IgG conjugated with horseradish peroxidase failed to detect antigens in soils. The indirect ELISA developed here can efficiently detect the fungus and help manage ginseng root rot disease in fields.

Development of indirect ELISA for the detection of canine adenovirus type 2 antibodies in dog sera

  • Yang, Dong-Kun;Kim, Ha-Hyun;Lee, Siu;Oh, Dongryul;Yoo, Jae Young;Hyun, Bang-Hun
    • Journal of Veterinary Science
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    • v.21 no.4
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    • pp.63.1-63.9
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    • 2020
  • Background: Canine adenovirus type 2 (CAV-2) induces infectious laryngotracheitis in members of the family Canidae, including dogs. To date, no ELISA kits specific for CAV-2 antibody have been commercialized for dogs in Korea. Objectives: We aimed to develop new indirect enzyme-linked immunosorbent assay (I-ELISA) to perform rapid, accurate serological surveys of CAV-2 in dog serum samples. Methods: In total, 165 serum samples were collected from dogs residing in Chungbuk and Gyeongbuk provinces between 2016 and 2018. The Korean CAV-2, named the APQA1701-40P strain, was propagated in Madin-Darby canine kidney cells and purified in an anion-exchange chromatography column for use as an antigen for I-ELISA. The virus-neutralizing antibody titers of CAV-2 in the dog sera were measured by virus neutralization (VN) test. Results: We compared the results obtained between the VN and new I-ELISA tests. The sensitivity, specificity, and accuracy of new I-ELISA were 98.6%, 86.4% and 97.0% compared with VN test, respectively. New I-ELISA was significantly correlated with VN (r = 0.91). Conclusions: These results indicate that new I-ELISA is useful for sero-surveillance of CAV-2 in dog serum.

Comparative Analysis of Screening Results from Various ELISA Formats Used for Detection of Anti-Erythropoietin Antibodies in Korean Patients

  • Ha, Sung-Kyu;Yang, Seung-Ju;Shin, Sug-Kyun;Jo, Young-Il;Baek, Kyung-Min;Hong, Seung-Hwa;Pack, Seung-Pil;Kim, Sung-Jo;Heo, Tae-Hwe
    • Biomolecules & Therapeutics
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    • v.18 no.2
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    • pp.184-190
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    • 2010
  • Clinical cases of pure red cell aplasia (PRCA) have been reported during the recombinant human erythropoietin (EPO) therapy for the anemia patients. PRCA is a rare hematological disorder leading to a severe anemia due to an almost complete stop of red blood cell production. Antibody (Ab)-associated PRCA is caused by the EPO-neutralizing Abs that eliminate the biological activity of EPO. In order to detect anti-EPO Abs in human sera, we performed conventional ELISA, directly coated bridging ELISA, and streptavidin coated bridging ELISA, and compared their sensitivity and specificity. Some false positive results were obtained in the conventional ELISA. One positive sample was detected successfully by streptavidin coated bridging ELISA, which was not appeared in the directly coated bridging ELISA. In conclusion, streptavidin coated bridging ELISA was substantially sensitive and specific format and one out of sixty-eight serum samples was proved to be anti-EPO positive.