Advances in Flow Cytometric Serology for Canine Visceral Leishmaniasis: Diagnostic Applications When Distinct Clinical Forms, Vaccination and Other Canine Pathogens Become a Challenge

Vet Immunol Immunopathol. 2009 Mar 15;128(1-3):79-86. doi: 10.1016/j.vetimm.2008.10.308. Epub 2008 Oct 17.

Abstract

We have previously reported the applicability of flow cytometry anti-fixed Leishmania infantum chagasi promastigotes IgG (FC-AFPA-IgG) as a novel serological device for laboratorial diagnosis of CVL. Herein, we validate throughout a blind study applied into a broader range of coded sera samples that FC-AFPA-IgG at serum dilution 1:8192 have an outstanding performance to discriminate the serological reactivity of canine visceral leishmaniasis (CVL, n=64) and Leishmune vaccines (VAC, n=62) and non-infected controls (NI, n=25). Moreover, we have evaluated the performance of indirect immunofluorescence antibody test (IFAT) and the crude-antigen enzyme-linked immunosorbent assay (ELISA) in parallel with FC-AFPA-IgG, to discriminate the seroreactivity of NI, CVL and VAC. Our data demonstrated that both ELISA and FC-AFPA-IgG showed similar performance to detect the seronegativity in 100% of NI, whereas FC-AFPA-IgG displayed better performance to exclude seropositivity in 100% of VAC. The high kappa agreement indexes observed suggested similar performance between these two serological testes when distinct clinical forms of CVL become a challenge. Furthermore, the FC-AFPA-IgG applied at sera dilution 1:8192 showed a remarkable performance to discriminate CVL from other co-endemic canine infections with high co-negativity in dogs infected with Trypanosoma cruzi and Leishmania braziliensis (86% and 84%, respectively). In conclusion, the data presented here re-emphasize the applicability of FC-AFPA-IgG as an innovative methodology able to discriminate post-infection imunomediated seroreactivity from that triggered by prophylactic immunization with minor cross-reactivity with other relevant canine pathogens, which may contribute as a supplementary assay for the CVL immunodiagnosis.

Publication types

  • Validation Study

MeSH terms

  • Animals
  • Antibodies, Protozoan / blood*
  • Cross Reactions
  • Diagnosis, Differential
  • Dog Diseases / diagnosis*
  • Dog Diseases / immunology
  • Dogs
  • Enzyme-Linked Immunosorbent Assay / veterinary
  • Female
  • Flow Cytometry / veterinary*
  • Immunoglobulin G / immunology
  • Leishmania infantum / immunology*
  • Leishmaniasis Vaccines / immunology*
  • Leishmaniasis, Visceral / diagnosis
  • Leishmaniasis, Visceral / immunology
  • Leishmaniasis, Visceral / veterinary*
  • Male
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Serologic Tests / veterinary

Substances

  • Antibodies, Protozoan
  • Immunoglobulin G
  • Leishmaniasis Vaccines