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.
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.
Laboratório de Vigilância em Leishmanioses, Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ, Brasil. fcribeiro@fiocruz.br
Flávia Coelho
FC
Ribeiro
Armando de O
Ade O
Schubach
Eliame
E
Mouta-Confort
Tânia M V
TM
Pacheco
Maria de Fátima
Mde F
Madeira
Luiz Cláudio de Souza
LC
Abboud
Carla de Oliveira
Cde O
Honse
Andreia Silva
AS
Alves
Mauro C A
MC
Marzochi
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D016022:Case-Control Studies; D004283:Dog Diseases / Q000175:diagnosis* / Q000276:immunology; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D019084:Fluorescent Antibody Technique, Indirect; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G