The Serological Diagnosis of Canine Leishmaniasis: Commercial ELISA or in House IFAT?

Pasquale Santoro¹, Andrea Vellusi²

¹Università degli Studi di Napoli Federico II - Dipartimento di Pediatria, Napoli, Italy.
²Diagnostica di Laboratorio (Di.Lab.) S.r.l., Napoli, Italy.

DOI: 10.4236/ojvm.2015.52005                

Abstract

The levels of anti-Leishmania infantum antibodies are relevant with the diagnosis and the followup of infected dogs. Both ELISA (Enzyme-Linked Immunosorbent Assay) and IFAT (Indirect Immuno-Fluorescent Antibody Test) may be employed to estimate the antibody levels in dogs, but at present, the correlation between ELISA absorbance and IFAT titer has not been investigated. In this paper, we compared the optical densities obtained with a commercial ELISA, Leiscan^?(Laboratorios Dr. Esteve S.A.), versus the titers obtained by in house IFAT. We measured ELISA absorbance of: 44 IFAT negative samples coming from an endemic area; 10 negative samples coming from a non endemic area; 29 samples with an IFAT titer between 1/40 and 1/80; 10 samples with an IFAT titer of 1/160; 9 samples with an IFAT titer of 1/320; 10 samples with an IFAT titer of 1/640; 10 samples with an IFAT titer ≥ of 1/1280. Results show that: a) there is a poor correlation between IFAT titer and ELISA absorbance; b) Leiscan^? is not able to distinguish between IFAT negative samples and IFAT titers up to 1:160; c) IFAT negative samples from an endemic or non endemic area show different ELISA absorbance; d) the performance of the kit may be improved by the use of a more appropriate cut-off.

Keywords

ELISA, IFAT, Leishmania infantum

Conflicts of Interest

The authors declare no conflicts of interest.

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