An evaluation of antigen capture assays for detecting active filarial antigens

2014 ◽  
Vol 89 (3) ◽  
pp. 352-358 ◽  
Author(s):  
R. Ravishankaran ◽  
N.S. Radhika ◽  
L. Ansel Vishal ◽  
S. Meenakshisundaram ◽  
A.A. Karande ◽  
...  
Keyword(s):  
Polyclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Capture Assay ◽  
Antigen Capture ◽  
Circulating Filarial Antigens ◽  
Detection Assay ◽  
Normal Individuals ◽  
Circulating Antigen ◽  
Endemic Normal

AbstractLymphatic filariasis is a parasitic disease of tropical countries. This is a disfiguring and painful disease contracted in childhood, but the symptoms become apparent only in later years. Diagnosis of filarial infection is very crucial for the management of the disease. The main objective of this study was to develop a filarial antigen-based immunological assay for the diagnosis and surveillance of the disease. Monoclonal and polyclonal antibodies were raised to the recombinant protein Brugia malayi vespid allergen homologue (VAH). Capture enzyme-linked immunosorbent assay (ELISA) was standardized utilizing various combinations of antibodies and evaluated with serum samples of endemic normal (EN, n= 110), microfilaraemic (MF, n= 65), chronic pathology (CP, n= 45) and non-endemic normal (NEN, n= 10) individuals. Of the 230 samples tested, VAH capture assay detected circulating antigen in 97.91% of bancroftian and 100% of brugian microfilaraemic individuals, and 5% of endemic normal individuals, comparable to the earlier reported SXP-1 antigen detection assay. However, the combination of VAH and SXP-1 (VS) capture ELISA was found to be more robust, detecting 100% of microfilaraemic individuals and with higher binding values. Thus an antigen capture immunoassay has been developed, which can differentiate active infection from chronic infection by detecting circulating filarial antigens in clinical groups of endemic areas.

scholarly journals Dynamics of Antigenemia and Coproantigens during a Human Fasciola hepatica Outbreak

1998 ◽  
Vol 36 (9) ◽  
pp. 2723-2726 ◽  
Author(s):  
Ana M. Espino ◽  
Ailén Díaz ◽  
Antonio Pérez ◽  
Carlos M. Finlay
Keyword(s):  
Fasciola Hepatica ◽  
Clinical Symptoms ◽  
Sandwich Elisa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
La Palma ◽  
Detection Assay ◽  
Circulating Antigen ◽  
Circulating Antigens ◽  
Stool Samples

In the present study the dynamics of antigenemia and coproantigens were studied in patients withFasciola hepatica infection during an outbreak occurring in La Palma, Pinar del Rı́o, in the West Province of Cuba. Stool and serum samples were collected from 67 patients and 40 healthy subjects. Stool samples were studied by a simple gravity sedimentation technique and an ES78 sandwich enzyme-linked immunosorbent assay (ELISA) for observation of eggs and detection of parasite coproantigens, respectively. Serum samples were also studied by the ES78 sandwich ELISA and an indirect ELISA to detect circulating antigens and antibodies, respectively. At the beginning of the study, 8 of 67 patients had patent infections and 59 had prepatent infections, which was determined by the recent consumption of lettuce contaminated with metacercariae of F. hepatica, the presence of clinical symptoms, and the absence of Fasciolaeggs in their stools. Patients with prepatent infections were monitored by all techniques until patency. Circulating antigens were not detected in patients with patent infections. However, coproantigens were clearly detected in all patients with patent infections. On the other hand, 28.8% of patients with prepatent infections tested positive for circulating antigens and 81.4% tested positive for coproantigens in the first stool sample studied. Only two other coproantigen determinations were necessary to diagnose 93.2% of the patients. While circulating antigen levels diminished in all patients during the infection, coproantigen levels increased. The present study demonstrates that the ES78 sandwich ELISA is a better tool than parasitological examination for diagnosis of active early infection, since by the combination of the circulating-antigen detection assay and the coproantigen detection assay 91% of patients were able to be diagnosed at the beginning of the study. In contrast, a coprologic analysis repeated over several weeks was necessary to diagnose 100% of the patients.

scholarly journals Standardization of dot-ELISA for the serological diagnosis of toxocariasis and comparision of the assay with ELISA

1992 ◽  
Vol 34 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Eide Dias Camargo ◽  
Paulo Mutuko Nakamura ◽  
Adelaide José Vaz ◽  
Marcos Vinícius da Silva ◽  
Pedro Paulo Chieffi ◽  
...  
Keyword(s):  
Low Cost ◽  
Clinical Signs ◽  
Toxocara Canis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Normal Individuals ◽  
Before And After ◽  
Dot Elisa ◽  
Stability Time

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.

scholarly journals Monoclonal Antibody-Based Antigen Capture Enzyme-Linked Immunosorbent Assay Reveals High Sensitivity of the Nucleocapsid Protein in Acute-Phase Sera of Severe Acute Respiratory Syndrome Patients

2005 ◽  
Vol 12 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Biao Di ◽  
Wei Hao ◽  
Yang Gao ◽  
Ming Wang ◽  
Ya-di Wang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Acute Phase ◽  
Detection Rate ◽  
Neutralization Test ◽  
Protein Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
N Protein ◽  
Antigen Capture ◽  
Healthy Donors

ABSTRACT Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients. The results of the N protein detection analysis were directly related to the serological analysis data. From 27 SARS patients who tested positive with the neutralization test, 100% of the 24 sera collected from 1 to 10 days after the onset of symptoms were positive for the N protein. N protein was not detected beyond day 11 in this group. The positive rates of N protein for sera collected at 1 to 5, 6 to 10, 11 to 15, and 16 to 20 days after the onset of symptoms for 414 samples from 298 serologically confirmed patients were 92.9, 69.8, 36.4, and 21.1%, respectively. For 294 sera from 248 serological test-negative patients, the rates were 25.6, 16.7, 9.3, and 0%, respectively. The N protein was not detected in 66 patients with cases of what was initially suspected to be SARS but serologically proven to be negative for SARS and in 197 serum samples from healthy donors and non-SARS febrile patients. The specificity of the assay was 100%. Furthermore, of 16 sera collected from four patients during the SARS recurrence in Guangzhou, 5 sera collected from 7 to 9 days after the onset of symptoms were positive for the N protein. N protein detection exhibited a high positive rate, 96 to 100%, between day 3 and day 5 after the onset of symptoms for 27 neutralization test-positive SARS patients and 298 serologically confirmed patients. The N protein detection rate continually decreased beginning with day 10, and N protein was not detected beyond day 19 after the onset of symptoms. In conclusion, an antigen capture ELISA reveals a high N protein detection rate in acute-phase sera of patients with SARS, which makes it useful for early diagnosis of SARS.

Quantification of serum amyloid P by enzyme-linked immunosorbent assay

1991 ◽  
Vol 37 (10) ◽  
pp. 1742-1745 ◽  
Author(s):  
R Saïle ◽  
A Kandoussi ◽  
M Deveaux ◽  
J Descamps ◽  
E Hachulla ◽  
...  
Keyword(s):  
Human Plasma ◽  
Immunosorbent Assay ◽  
Polyclonal Antibodies ◽  
Serum Amyloid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Amyloid P ◽  
Assay Procedure ◽  
Normal Individuals ◽  
Sandwich Type ◽  
Amyloid P

Abstract This enzyme-linked immunosorbent assay procedure for quantifying serum amyloid P (SAP) in human plasma makes use of affinity-purified polyclonal antibodies to SAP in a "sandwich"-type format. The procedure is sensitive, reproducible, simple, and easily automatable. Results correlate well with those by a rocket immunoelectrophoresis method performed with the same antibodies. Sera from apparently normal individuals had a mean SAP content of 44.17 mg/L and increased with age.

scholarly journals Immunodetection of Fasciola gigantica Circulating Antigen in Sera of Infected Individuals for Laboratory Diagnosis of Human Fascioliasis

2013 ◽  
Vol 20 (10) ◽  
pp. 1569-1577 ◽  
Author(s):  
Abdelfattah M. Attallah ◽  
Faisal A. Bughdadi ◽  
Atef M. El-Shazly ◽  
Hisham Ismail
Keyword(s):  
Laboratory Diagnosis ◽  
Fasciola Gigantica ◽  
Antigen Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Target Antigen ◽  
Immunoperoxidase Staining ◽  
Serum Samples ◽  
Content Type ◽  
Human Fascioliasis ◽  
Circulating Antigen

ABSTRACTCurrently, the laboratory diagnosis of human fascioliasis is based on the parasitological examination of parasite eggs in stool specimens and serological detection of specific antibodies in serum samples, which are often unreliable diagnostic approaches. Ideally, a sensitive and specific diagnostic test forFasciolainfection should be based on the detection of circulatingFasciolaantigen, which implies active infection. Here, a 27-kDa-molecular-mass antigen was identified in aFasciola giganticaadult worm antigen preparation, excretory-secretory products, and sera fromF. gigantica-infected individuals, and it was not detected in antigenic extracts of other parasites and sera from noninfected individuals. The target antigen was isolated and partially characterized as a protein. Immunoperoxidase staining located the target epitope within teguments and guts ofF. giganticaadult worms. The performance characteristics of a newly developed enzyme-linked immunosorbent assay (ELISA) based onF. giganticacirculating antigen detection in serum (FgCA-27 ELISA) were investigated using sera of 120 parasitologically diagnosedF. gigantica-infected individuals and 80 noninfected individuals. The area under the receiving operating characteristic (ROC) curve (AUC) for ELISA was significantly high (AUC = 0.961,P< 0.0001) for discriminatingFasciola-infected and noninfected individuals. The developed assay showed high degrees of sensitivity, specificity, and efficiency (>93%), and a significant correlation (r= 0.715,P< 0.0001) between antigen level and parasite egg count was shown. In conclusion, a 27-kDaFasciolaantigen was identified in sera ofF. gigantica-infected individuals. A highly sensitive and specificFasciolaantigen detection assay, FgCA-27 ELISA, was developed for laboratory diagnosis of human fascioliasis.

scholarly journals Development of an Immunoglobulin M (IgM) Capture Enzyme-Linked Immunosorbent Assay for Detection of Equine and Swine IgM Antibodies to Vesicular Stomatitis Virus

2001 ◽  
Vol 8 (3) ◽  
pp. 475-481 ◽  
Author(s):  
En-min Zhou ◽  
Jose Riva ◽  
Alfonso Clavijo
Keyword(s):  
Vesicular Stomatitis Virus ◽  
Immunosorbent Assay ◽  
Polyclonal Antibodies ◽  
Competitive Elisa ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Vesicular Stomatitis ◽  
Elisa Plate

ABSTRACT An immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (MC-ELISA) was developed for the detection of primary infection of vesicular stomatitis virus (VSV) in equine and swine sera. The test was based on the use of biotinylated sheep antibodies against equine or swine IgM molecules bound to a streptavidin-coated ELISA plate. The captured IgM antibodies were detected by application of antigens prepared from the New Jersey and the Indiana VSV serotypes (VSV-NJ and VSV-IN, respectively) and mouse polyclonal antibodies against VSV-NJ and VSV-IN. The MC-ELISA was compared to a competitive ELISA (C-ELISA) and the standard microtiter serum neutralization (MTSN) assay by testing serum samples from horses and pigs experimentally infected with VSV-NJ or VSV-IN. The MC-ELISA detected specific homologous IgM antibodies from equine and swine sera as early as 5 and 4 days postinfection (DPI), respectively, and as late as 35 DPI. The MTSN test also detected antibodies as early as 5 DPI and as late as 160 DPI. In a similar fashion, the C-ELISA detected antibodies from 6 to 7 DPI and as late as 160 DPI. These results demonstrated that the MC-ELISA is a useful test for serodiagnosis of primary VSV infection in horses and pigs.

scholarly journals Use of a Novel Enzyme Immunoassay Based on Detection of Circulating Antigen in Serum for Diagnosis of Helicobacter pylori Infection

2004 ◽  
Vol 11 (4) ◽  
pp. 775-779 ◽  
Author(s):  
Abdelfattah M. Attallah ◽  
Hisham Ismail ◽  
Gellan G. Ibrahim ◽  
Mohamed Abdel-Raouf ◽  
Ahmed M. El-Waseef ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Endoscopic Biopsy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Target Antigen ◽  
Serum Samples ◽  
Predictive Values ◽  
Biopsy Specimens ◽  
Significant Difference ◽  
Circulating Antigen ◽  
H Pylori

ABSTRACT Recently, noninvasive diagnostic tests for Helicobacter pylori infection have gained in significance. We have developed a sensitive and specific noninvasive immunoassay based on the detection of an H. pylori circulating antigen (HpCA) in sera from H. pylori-infected individuals. Monospecific antibody and Western blot analyses were used to demonstrate the presence of the target antigen in H. pylori cell lysate and serum samples. A novel enzyme-linked immunosorbent assay (ELISA) was developed for the detection of HpCA in serum. Endoscopic biopsy specimens from the gastric antra of 221 individuals (143 males and 78 females) with dyspeptic symptoms were evaluated for H. pylori infection, with culture used as a “gold standard” for diagnosis. The target H. pylori antigen was identified at 58 kDa. HpCA has been detected by ELISA with high degrees of sensitivity, specificity, and efficiency (>90%), and ELISA results show no significant difference (P > 0.05) from results of H. pylori culture of gastric biopsy specimens. The test's positive and negative predictive values were also high (95 and 86%, respectively). In conclusion, a sensitive and specific immunoassay was developed for the detection of HpCA in human serum. This test can be applied for noninvasive laboratory and field diagnoses of H. pylori infection.

scholarly journals Development of Immunoassays for Detection of Francisella tularensis Lipopolysaccharide in Tularemia Patient Samples

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 924
Author(s):  
Emily E. Hannah ◽  
Sujata G. Pandit ◽  
Derrick Hau ◽  
Haley L. DeMers ◽  
Kayleigh Robichaux ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Point Of Care ◽  
Natural Infection ◽  
Lateral Flow ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Potential Threat ◽  
Infectious Dose ◽  
Antigen Capture ◽  
Wide Range

Francisella tularensis is the causative agent of tularemia, a zoonotic bacterial infection that is often fatal if not diagnosed and treated promptly. Natural infection in humans is relatively rare, yet persistence in animal reservoirs, arthropod vectors, and water sources combined with a low level of clinical recognition make tularemia a serious potential threat to public health in endemic areas. F. tularensis has also garnered attention as a potential bioterror threat, as widespread dissemination could have devastating consequences on a population. A low infectious dose combined with a wide range of symptoms and a short incubation period makes timely diagnosis of tularemia difficult. Current diagnostic techniques include bacterial culture of patient samples, PCR and serological assays; however, these techniques are time consuming and require technical expertise that may not be available at the point of care. In the event of an outbreak or exposure a more efficient diagnostic platform is needed. The lipopolysaccharide (LPS) component of the bacterial outer leaflet has been identified previously by our group as a potential diagnostic target. For this study, a library of ten monoclonal antibodies specific to F. tularensis LPS were produced and confirmed to be reactive with LPS from type A and type B strains. Antibody pairs were tested in an antigen-capture enzyme-linked immunosorbent assay (ELISA) and lateral flow immunoassay format to select the most sensitive pairings. The antigen-capture ELISA was then used to detect and quantify LPS in serum samples from tularemia patients for the first time to determine the viability of this molecule as a diagnostic target. In parallel, prototype lateral flow immunoassays were developed, and reactivity was assessed, demonstrating the potential utility of this assay as a rapid point-of-care test for diagnosis of tularemia.

Assessment of monoclonal antibodies to Echinococcus granulosus Antigen 5 and Antigen B for detection of human hydatid circulating antigens

Parasitology ◽  
1993 ◽  
Vol 106 (1) ◽  
pp. 75-81 ◽  
Author(s):  
D. Liu ◽  
M. D. Rickard ◽  
M. W. Lightowlers
Keyword(s):  
Monoclonal Antibodies ◽  
Echinococcus Granulosus ◽  
Binding Capacity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Antigen B ◽  
Detection Assay ◽  
Circulating Antigens ◽  
Normal Human ◽  
Antigen 5

SUMMARYFour monoclonal antibodies (MAb) to Echinococcus granulosus Antigen 5 (Ag5) and Antigen B (AgB) were assessed in an enzyme-linked immunosorbent assay (ELISA) for detection of circulating antigens (CAg) in sera of human patients with E. granulosus infection. Around 5·5–8% of 200 sera from 42 surgically proven hydatid patients contained detectable CAg by individual MAb. The combined detection rate for CAg, using four MAb, was 19% (38/200). Although hydatid CAg was detected by MAb in at least one serum sample from 21 of 42 patients, some patients remained negative in the assay regardless of the time when serum samples were taken (pre- or post-operatively), or of the continuing presence of hydatid cysts, their location or fertility. In addition, it was observed that the binding capacity of MAb for sheep hydatid cyst fluid antigen (SHCF) was somewhat reduced in the presence of normal human serum. The CAg detection assay would only be useful for assessment of hydatid infection status in patients with detectable CAg in serum samples.

scholarly journals Development of Antibodies against Anthrose Tetrasaccharide for Specific Detection of Bacillus anthracis Spores

2009 ◽  
Vol 16 (12) ◽  
pp. 1728-1737 ◽  
Author(s):  
Andrea Kuehn ◽  
Pavol Kovác ◽  
Rina Saksena ◽  
Norbert Bannert ◽  
Silke R. Klee ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Bacillus Anthracis ◽  
Polyclonal Antibodies ◽  
Immunofluorescence Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Detection ◽  
Complex Samples ◽  
Capture Assay ◽  
Bacillus Anthracis Spores ◽  
Spore Detection

ABSTRACT Methods for the immunological detection of Bacillus anthracis in various environmental samples and the discrimination of B. anthracis from other members of the B. cereus group are not yet well established. To generate specific discriminating antibodies, we immunized rabbits, mice, and chickens with inactivated B. anthracis spores and, additionally, immunized rabbits and mice with the tetrasaccharide β-Ant-(1→3)-α-l-Rhap-(1→3)-α-l-Rhap-(1→2)-l-Rhap. It is a constituent of the exosporium glycoprotein BclA and contains the newly discovered sugar anthrose 2-O-methyl-4-(3-hydroxy-3-methylbutamido)-4,6-dideoxy-β-d-glucose. The BclA protein is a major component of the exosporium of B. anthracis spores and is decorated by the tetrasaccharide indicated above. The anthrose-containing tetrasaccharide chain seems to be highly specific for B. anthracis, which makes it a key biomarker for the detection of these spores. The different immunizations led to anthrose-reactive polyclonal and monoclonal antibodies which were analyzed by various methods to characterize their ability to discriminate between B. anthracis and other Bacillus spp. Multiple applications, such as enzyme-linked immunosorbent assay, indirect immunofluorescence assay, and electron microscopy, revealed the specificities of the polyclonal and monoclonal antibodies generated for B. anthracis spore detection. All polyclonal antibodies were able to correctly identify the B. anthracis strains tested and showed only minimal cross-reactivities with other Bacillus strains. Moreover, the antibodies generated proved functional in a new capture assay for B. anthracis spores and could therefore be useful for the detection of spores in complex samples.

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