scholarly journals Serological reactivity of different antigenic preparations of Leishmania (Leishmania) amazonensis and the Leishmania braziliensis complex

2008 ◽  
Vol 41 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Adriano Gomes-Silva ◽  
Maria Aparecida Souza ◽  
Sandra Regina Afonso-Cardoso ◽  
Lívia Resende Andrade ◽  
Reynaldo Dietze ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Affinity Chromatography ◽  
Healthy Volunteers ◽  
Concanavalin A ◽  
Leishmania Amazonensis ◽  
Leishmania Braziliensis ◽  
Elisa Assay ◽  
Serum Samples ◽  
Sensitivity Range ◽  
Serological Reactivity

Total antigen from Leishmania (Leishmania) amazonensis and isolates from the Leishmania braziliensis complex, along with their respective antigenic fractions obtained by affinity chromatography on concanavalin-A-Sepharose and jacalin-agarose columns evaluated using immunoenzymatic ELISA assay. For this, serum samples from 229 patients were used, grouped as American tegmental leishmaniasis (nº=58), visceral leishmaniasis (nº=28), Chagas disease (nº=49), malaria (nº=32), tuberculosis (nº=13) and healthy volunteers (nº=49). Samples from American tegmentary leishmaniasis showed higher reactivity with antigens isolated from the Leishmania braziliensis complex than with antigens from Leishmania amazonensis (p<0.001). ELISA assays showed a sensitivity range from 60% to 95% with antigens isolated from the Leishmania braziliensis complex. There was marked nonspecific reactivity among serum samples with the use of antigenic fractions binding with concanavalin-A and jacalin from both Leishmania complexes, in comparison with other antigens (p<0.001). The results presented in this study suggest that the use of homologous antigens increases the efficiency of anti-Leishmania immunoglobulin detection, which may be very valuable for diagnostic purposes.

scholarly journals Use of elisa employing homologous and heterologous antigens for the detection of IgG and subclasses (IgG1 and IgG2) in the diagnosis of Canine visceral leishmaniasis

2011 ◽  
Vol 53 (5) ◽  
pp. 283-289 ◽  
Author(s):  
Flávia Coelho Ribeiro ◽  
Armando de O. Schubach ◽  
Eliame Mouta-Confort ◽  
Tânia M.V. Pacheco ◽  
Maria de Fátima Madeira ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Large Scale ◽  
Cross Reactivity ◽  
Leishmania Braziliensis ◽  
Leishmania Chagasi ◽  
Serum Samples ◽  
Canine Ehrlichiosis ◽  
Control Serum ◽  
Homologous Antigen ◽  
Heterologous Antigens

Indirect immunofluorescence is the method recommended for the diagnosis of visceral leishmanisis in dogs, however, the accuracy of this technique is low and its use on a large scale is limited. Since ELISA does not present these limitations, this technique might be an option for the detection of IgG or specific IgG1 and IgG2 subclasses. Canine ehrlichiosis is an important differential diagnosis of American Visceral Leishmaniasis (AVL). The present study compared ELISA using Leishmania chagasi and Leishmania braziliensis antigen for the detection of anti-Leishmania IgG and subclasses in serum samples from 37 dogs naturally infected with L. chagasi (AVL) and in samples from four dogs co-infected with L. braziliensis and L. chagasi (CI). The occurrence of cross-reactivity was investigated in control serum samples of 17 healthy dogs (HC) and 35 infected with Ehrlichia canis (EC). The mean optical density obtained for the detection of IgG was significantly higher when L. chagasi antigen was used, and was also higher in subgroup VLs (symptomatic) compared to subgroup Vla (asymptomatic). The correlation between IgG and IgG1 was low. The present results suggest that IgG ELISA using homologous antigen yields the best results, permitting the diagnosis of asymptomatic L. chagasi infection and the discrimination between cases of AVL and ehrlichiosis in dogs.

scholarly journals Evaluation of a Prototype Flow Cytometry Test for Serodiagnosis of Canine Visceral Leishmaniasis

2013 ◽  
Vol 20 (12) ◽  
pp. 1792-1798 ◽  
Author(s):  
Henrique Gama Ker ◽  
Wendel Coura-Vital ◽  
Rodrigo Dian de Oliveira Aguiar-Soares ◽  
Bruno Mendes Roatt ◽  
Nádia das Dores Moreira ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Visceral Leishmaniasis ◽  
Cross Reactivity ◽  
Leishmania Braziliensis ◽  
Canine Visceral Leishmaniasis ◽  
Predictive Values ◽  
Content Type ◽  
Prototype Test ◽  
Serological Reactivity ◽  
Positive Results

ABSTRACTDiagnosing canine visceral leishmaniasis (CVL) is a critical challenge since conventional immunoserological tests still present some deficiencies. The current study evaluated a prototype flow cytometry serology test, using antigens and fluorescent antibodies that had been stored for 1 year at 4°C, on a broad range of serum samples. Noninfected control dogs andLeishmania infantum-infected dogs were tested, and the prototype test showed excellent performance in differentiating these groups with high sensitivity, specificity, positive and negative predictive values, and accuracy (100% in all analyses). When the CVL group was evaluated according to the dogs' clinical status, the prototype test showed outstanding accuracy in all groups with positive serology (asymptomatic II, oligosymptomatic, and symptomatic). However, in dogs which had positive results by PCR-restriction fragment length polymorphism (RFLP) but negative results by conventional serology (asymptomatic I), serological reactivity was not observed. Additionally, sera from 40 dogs immunized with different vaccines (Leishmune, Leish-Tec, or LBSap) did not present serological reactivity in the prototype test. Eighty-eight dogs infected with other pathogens (Trypanosoma cruzi,Leishmania braziliensis,Ehrlichia canis, andBabesia canis) were used to determine cross-reactivity and specificity, and the prototype test performed well, particularly in dogs infected withB. canisandE. canis(100% and 93.3% specificities, respectively). In conclusion, our data reinforce the potential of the prototype test for use as a commercial kit and highlight its outstanding performance even after storage for 1 year at 4°C. Moreover, the prototype test efficiently provided accurate CVL serodiagnosis with an absence of false-positive results in vaccinated dogs and minor cross-reactivity against other canine pathogens.

scholarly journals Canines vaccinated against visceral leishmaniasis develop a serological response to the Leishmania braziliensis antigen

2018 ◽  
Vol 39 (2) ◽  
pp. 573
Author(s):  
Julia De Assis Pinheiro ◽  
Silas Garcia Giori ◽  
Sayanne Luns Hatum de Almeida ◽  
Rafael Assis de Souza ◽  
Ana Paula Madureira ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Cross Reactivity ◽  
Leishmania Braziliensis ◽  
Soluble Antigen ◽  
Serological Response ◽  
Serum Samples ◽  
Asymptomatic Group ◽  
Post Vaccination ◽  
Common Antigens ◽  
Positive Frequency

American cutaneous leishmaniasis (ACL) is a zoonosis caused by Leishmania, a protozoan. Common antigens occur in the strains found in America, which allow antigenic cross-reactivity. Therefore, multivalent vaccines can be used for this pathogen. In this study, we investigated the efficacy of two different commercial vaccines for visceral leishmaniasis to induce an immune response to the soluble L. (Viannia) braziliensis antigens. In 2014, 70 seronegative dogs from the municipality of Iúna (Espírito Santo State, Brazil) were vaccinated and serologically evaluated by ELISA and immunoblotting by using the soluble antigen of L. braziliensis. Of the 121 dogs initially selected, only 70 received vaccination because 51 dogs tested positive by ELISA, yielding a positive frequency of 42.14% in the asymptomatic group. These 70 dogs were divided into two equal groups and administered three doses of each vaccine, according to the manufacturers’ instructions. We found that the sera of dogs immunized with three doses of both vaccines A and B had antibodies against the soluble antigens of L. (V.) braziliensis, as determined by ELISA and immunoblotting 120 days post vaccination. Antibodies produced in response to vaccines A and B were found in 22/35 and 18/35 serum samples, respectively, at T1 (120 days), while 7/35 and 4/35 serum samples tested positive at T2 (240 days). Furthermore, immunoblotting allowed us to differentiate between vaccinated and asymptomatic dogs.

scholarly journals Seroprevalence of Anti-SARS-CoV-2 IgG and IgM among Adults over 65 Years Old in the South of Italy

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 483
Author(s):  
Immacolata Polvere ◽  
Alfredina Parrella ◽  
Giovanna Casamassa ◽  
Silvia D’Andrea ◽  
Annamaria Tizzano ◽  
...  
Keyword(s):  
Antibody Response ◽  
Immunoglobulin M ◽  
Molecular Testing ◽  
Elisa Assay ◽  
The South ◽  
Serum Samples ◽  
Serological Screening ◽  
Rna Detection ◽  
In Vitro Diagnostic

SARS-CoV-2 is a zoonotic betacoronavirus associated with worldwide transmission of COVID-19 disease. By the beginning of March, WHO reported about 113,820,000 confirmed cases including more than 2,527,000 deaths all over the world. However, the true extent of virus circulation or its real infection/fatality ratio is not well-estimated due to the huge portion of asymptomatic infections. In this observational study, we have estimated the prevalence of specific immunoglobulin M and G directed towards SARS-CoV-2 antigen in a cohort of 1383 adult volunteers aged over 65 years old, living in the district of Benevento, in the South of Italy. Serological screening was carried out on capillary blood in September 2020, seven months after pandemic outbreak in Italy, to evaluate virus circulation and antibody response among elderly adults, in which severe symptoms due to viral infection are more common. The overall seroprevalence of anti-SARS-CoV-2 antibodies was 4.70% (CI 3.70%–5.95%) with no statistically significant differences between sexes. Among these, 69.69% (CI 55.61%–77.80%) tested positive to IgM, 23.08% (CI 14.51%–34.64%) to IgG and 9.23% (CI 4.30%–18.71%) was positive for both. All patients that were positive to IgM underwent molecular testing through RT-qPCR on oral-rhino pharyngeal swabs and only one specimen was positive for SARS-CoV-2 RNA detection. Instead, the presence of IgG from screened volunteers was confirmed by re-testing serum samples using both an ELISA assay validated for in vitro diagnostic use (IVD) and a recently published synthetic peptide-based ELISA assay. In conclusion, our report suggests that (1) early restrictions were successful in limiting COVID-19 diffusion in the district of Benevento; (2) rapid serological analysis is an ideal testing for both determining real seroprevalence and massive screening, whereas detection of viral RNA remains a gold standard for identification of infected patients; (3) even among people without COVID-19 related symptoms, the antibody response against SARS-CoV-2 antigens has individual features.

scholarly journals Validity of different copeptin assays in the differential diagnosis of the polyuria-polydipsia syndrome

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Clara Odilia Sailer ◽  
Julie Refardt ◽  
Claudine Angela Blum ◽  
Ingeborg Schnyder ◽  
Jose Alberto Molina-Tijeras ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Diagnostic Accuracy ◽  
Healthy Volunteers ◽  
Primary Outcome ◽  
The Other ◽  
Poor Correlation ◽  
Elisa Assay ◽  
Moderate Correlation ◽  
High Diagnostic Accuracy ◽  
Osmotic Stimulation

AbstractThe aim of this study was to correlate three commercially available copeptin assays and their diagnostic accuracy in the differential diagnosis of the polyuria-polydipsia syndrome. Analyzed data include repeated copeptin measures of 8 healthy volunteers and 40 patients with polyuria-polydipsia syndrome undergoing osmotic stimulation and of 40 patients hospitalized with pneumonia. Copeptin was measured using the automated Brahms KRYPTOR, the manual Brahms LIA and the manual Cloud Clone ELISA assay. Primary outcome was the interrater correlation coefficient (ICC) and diagnostic accuracy in the polyuria-polydipsia syndrome of the three assays. In healthy volunteers, there was a moderate correlation for the KRYPTOR and LIA (ICC 0.74; 95% CI 0.07 to 0.91), and a poor correlation for the KRYPTOR and ELISA (ICC 0.07; 95% CI − 0.06 to 0.29), as for the LIA and ELISA (ICC 0.04; 95% CI − 0.04 to 0.17). The KRYPTOR had the highest diagnostic accuracy (98% (95% CI 83 to100)), comparable to the LIA (88% (95% CI 74 to 100)), while the ELISA had a poor diagnostic accuracy (55% (95% CI 34 to 68)) in the differential diagnosis of the polyuria-polydipsia syndrome. The KRYPTOR and LIA yield comparable copeptin concentrations and high diagnostic accuracy, while the ELISA correlates poorly with the other two assays and shows a poor diagnostic accuracy for polyuria-polydipsia patients. The current copeptin cut-off is valid for the KRYPTOR and LIA assay. Our results indicate that interpretation with other assays should be performed with caution and separate validation studies are required before their use in differentiating patients with polyuria-polydipsia syndrome.Trial registration: NCT02647736 January 6, 2016/NCT01940614 September 12, 2013/NCT00973154 September 9, 2009.

scholarly journals Determination of Mycoplasma bovis specific antibodies in blood sera of asymptomatic carriers-calves in three farms in the Republic of Serbia by using indirect ELISA assay

2017 ◽  
Vol 65 (2) ◽  
pp. 79
Author(s):  
D. VOJINOVIĆ ◽  
A. VASIĆ ◽  
J. ŽUTIĆ ◽  
B. DURIČIĆ ◽  
Z. ILIĆ ◽  
...  
Keyword(s):  
Indirect Elisa ◽  
Mycoplasma Bovis ◽  
Elisa Assay ◽  
Serum Samples ◽  
Asymptomatic Carriers ◽  
Elisa Kit ◽  
Cattle Blood ◽  
The Republic ◽  
The Individual

Blood serum samples of asymptomatic carriers-calves were collected from three farms in the territory of the Republic of Serbia during 2011 and 2012. Commercial Mycoplasma bovis ELISA kit (Bio-X Diagnostics, Belgique) for serological diagnosis from cattle blood sera and milk was used in this research. Calves’ blood sera were tested using immunoenzymatic indirect ELISA assay as described by manufacturer’s instructions. From 5603 blood sera of asymptomatic carriers-calves 144 (2,57%) samples were tested positive for the presence of specific Mycoplasma bovis antibodies. In three different farms proportions of seropositive samples varied from 0,32% to 10,6% in regard to total number of tested samples from the individual farms. In this paper we present the results of Mycoplasma bovis prevalence in asymptomatic carriers-calves.

Diagnostic application of sensitive and specific phage-exposed epitopes for visceral leishmaniasis and human immunodeficiency virus coinfection

Parasitology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Fernanda F. Ramos ◽  
Grasiele S. V. Tavares ◽  
Fernanda Ludolf ◽  
Amanda S. Machado ◽  
Thaís T. O. Santos ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Visceral Leishmaniasis ◽  
Patient Treatment ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diagnostic Purpose ◽  
Serum Samples ◽  
Prognostic Effect ◽  
Specific Phage ◽  
Hiv Coinfection ◽  
Immunodeficiency Virus

Abstract The diagnosis of visceral leishmaniasis (VL) has improved with the search of novel antigens; however, their performance is limited when samples from VL/human immunodeficiency virus (HIV)-coinfected patients are tested. In this context, studies conducted to identify more suitable antigens to detect both VL and VL/HIC coinfection cases should be performed. In the current study, phage display was performed using serum samples from healthy subjects and VL, HIV-infected and VL/HIV-coinfected patients; aiming to identify novel phage-exposed epitopes to be evaluated with this diagnostic purpose. Nine non-repetitive and valid sequences were identified, synthetized and tested as peptides in enzyme-linked immunosorbent assay experiments. Results showed that three (Pep2, Pep3 and Pep4) peptides showed excellent performance to diagnose VL and VL/HIV coinfection, with 100% sensitivity and specificity values. The other peptides showed sensitivity varying from 50.9 to 80.0%, as well as specificity ranging from 60.0 to 95.6%. Pep2, Pep3 and Pep4 also showed a potential prognostic effect, since specific serological reactivity was significantly decreased after patient treatment. Bioinformatics assays indicated that Leishmania trypanothione reductase protein was predicted to contain these three conformational epitopes. In conclusion, data suggest that Pep2, Pep3 and Pep4 could be tested for the diagnosis of VL and VL/HIV coinfection.

Affinity chromatography used in distinguishing alpha-fetoprotein in serum from patients with tumors of hepatic parenchyma and of germ cells.

1984 ◽  
Vol 30 (7) ◽  
pp. 1257-1258 ◽  
Author(s):  
P K Buamah ◽  
C Cornell ◽  
A W Skillen
Keyword(s):  
Germ Cell ◽  
Affinity Chromatography ◽  
Germ Cells ◽  
Concanavalin A ◽  
Primary Liver Cancer ◽  
Germ Cell Tumors ◽  
Alpha Fetoprotein ◽  
Hepatic Parenchyma ◽  
Liver Cancers ◽  
Serum Alpha Fetoprotein

Abstract We used affinity chromatography on concanavalin A Sepharose to study the serum alpha-fetoprotein of 10 patients with histologically proven germ-cell tumors and 12 patients with primary liver cancer. Less than 50% of the fetoprotein from germ-cell tumors bound to concanavalin A, as compared with more than 80% of the alpha-fetoprotein from primary liver cancers.

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