Associations among immunological, parasitological and clinical parameters in canine visceral leishmaniasis: Emaciation, spleen parasitism, specific antibodies and leishmanin skin test reaction

Abstract

Associations among parameters commonly used as markers of infection by Leishmania sp., or of susceptibility to visceral leishmaniasis, were investigated in 325 stray dogs from an area where this disease is endemic. Evidence of infection (presence of Leishmania in splenic cultures, positive leishmanin skin test (LST) or detection of anti-Leishmania antibody activity in the serum) was found in 57% of the animals. Both evidence of weight loss (chi(2)-test, P=0.0005) and presence of specific antibody activity in the serum (chi(2)-test, P<0.0001) were directly associated with positive splenic culture. The frequencies of animals with positive splenic culture were directly correlated with the intensities of antibody activity in the serum as measured by ELISA (relative risk of 3.4 for animals with moderate antibody levels and relative risk of 8.43 for animals with high-antibody levels). A negative association was observed between positive leishmanin skin test results and emaciation (chi(2), P=0.0089). Furthermore, animals with positive splenic cultures and negative leishmanin skin test results had higher levels of total serum IgG (Kruskal-Wallis test, P=0.001) and IgG2 (Kruskal-Wallis test, P=0.05) than animals with negative splenic cultures, and were more emaciated than animals with negative LST results and positive splenic cultures. The data presented herein suggest that associating these common parameters may improve their performance in predicting susceptibility to canine visceral leishmaniasis.

Genome-Wide Association Study of Cell-Mediated Response in Dogs Naturally Infected by Leishmania infantum

“…Thirty percent of the infected dogs were LST positive in the present study. This is a positivity slightly higher than that observed in mongrel dogs from other areas of endemicity in Brazil, which was approximately 22% (22,23). Our findings suggest genetic advantages in LST-positive dogs which favor an inflammatory response.…”

“…The LST is a marker of effective cell-mediated immunity (CMI). A positive LST is often associated with subclinical infec-tion, although it has also been rarely described in sick dogs (12,(22)(23)(24). The lymphocyte proliferation assay (LPA) is usually employed to evaluate the adaptive response triggered in dogs infected by L. infantum (12,25).…”

Characterization of Novel Leishmania infantum Recombinant Proteins Encoded by Genes from Five Families with Distinct Capacities for Serodiagnosis of Canine and Human Visceral Leishmaniasis

“…[10][11][12] Detection of canine infection and/or disease essentially can be carried out with the methods mentioned above. [13][14][15][16] However, because most persons with the disease produces antibodies against Leishmania , diagnoses of clinically suspected human cases are often confirmed or the infection in dogs is indicated by serologic immunoassays. [17][18][19][20][21][22][23] These assays are carried out mainly with antigens from cultured Leishmania promastigote forms, which may also react with antibodies associated with other infectious diseases such as Chagas' disease and malaria, and thus produce falsepositive results.…”

Questionnaire-based survey on canine leishmaniosis (Leishmania infantum) in Greece

“…Συμφωνά με τις απαντήσεις στο ερωτηματολόγιο, αυτός συνήθως πε ριορίζεται σε μια ή περισσότερες ορολογικές εξετά σεις και συγκεκριμένα στα διάφορα kit γρήγορης ο ρολογικής εξέτασης στο ιατρείο, τον έμμεσο ανοσο-φθορισμό ή/και την ELISA. Είναι γνωστό ότι όλοι σχεδόν οι συμπτωματικοί σκύλοι είναι θετικοί στην ο ρολογική εξέταση, ανεξάρτητα από τη μέθοδο που ε φαρμόζεται, και κατά συνέπεια η ευαισθησία τους για τη διάγνωση της ΛΣ είναι αρκετά ικανοποιητική (Koutinas et al 1999, Saridomichelakis et al 2005b, da Costa-Val et al 2007, Dos-Santos et al 2008. Επιπλέον, στην Ελλάδα δεν έχουν βρεθεί μέχρι σήμερα στο σκΰλο λοιμώξεις από τα άλλα είδη Leishmania spp, εκτός της L. infantum, οΰτε από το Trypanosoma spp., που λόγω αντιγονικής ομοιότητας μπορεί να οδηγήσουν σε ψευδώς θετικά ορολογικά α ποτελέσματα (Vercammen et al 1997, Barbosa-DeDeus et al 2002, de Fatima Madeira et al 2006, Ferreira Ede et al 2007).…”