title: Improvement of direct agglutination test (DAT) for laboratory diagnosis of visceral leishmaniasis in Brazil.
abstract: We previously standardized the direct agglutination test (DAT) to detect anti-Leishmania chagasi promastigote antibodies (DAT-LPC) with good sensitivity and specificity for diagnosing visceral leishmaniasis (VL). In this paper, we present a technical upgrade by introducing some modifications into the antigen preparation. This antigen was evaluated in DAT (DAT-Mod) using 61 sera samples from VL patients and 96 samples from patients with other diseases. The DAT-Mod presented a cut-off of 1:100, satisfactory reproducibility (VC <5.8), sensitivity of 93.4%, specificity of 96.9%, and diagnostic efficiency of 95.5%. The improvement in antigen preparation reduced inter-batch variations and resulted in a high test performance.
authors.affiliation: Clinical Research Laboratory, Centro de Pesquisa René Rachou, Fundação Oswaldo Cruz, Av. Augusto de Lima, 1715, Belo Horizonte, MG, 30190-002, Brazil.
authors.forename: Edward
authors.initials: E
authors.lastname: Oliveira
authors.forename: Mariana Junqueira
authors.initials: MJ
authors.lastname: Pedras
authors.forename: Isabella Elias Morais
authors.initials: IE
authors.lastname: de Assis
authors.forename: Ana
authors.initials: A
authors.lastname: Rabello
mesh_terms: D000372:Agglutination Tests / Q000592:standards*; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000097:blood*; D001938:Brazil; D005260:Female; D006801:Humans; D007893:Leishmania donovani / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan