Cardiac biomarkers in dogs with visceral leishmaniasis

Although only a few studies have focused on the cardiac alterations in Leishmania spp. infected dogs, myocardial inflammation ascribed to such parasite has been documented in some animals. In spite of the increasing popularity of cardiac biomarkers in veterinary medicine in recent years, it remains unknown how most of these substances would perform in dogs with visceral leishmaniasis. In this study, we hypothesised that Leishmania spp. would damage cardiac myofibers resulting in increased circulating levels of cardiac specific markers in dogs. Therefore, biomarkers of myocyte injury and stress were investigated in 18 dogs with naturally-occurring visceral leishmaniasis presenting varying clinical signs, including completely asymptomatic animals. The median (min-max) concentrations of NT-proANP, NT-proBNP, cTnI, and CK-MB were 1138.0 (875-1175) pmol/L, 1160.0 (803-2034) fmol/L, 0.22 (0.15-0.51) ng/mL, and 116.7 (113-222) U/L, respectively. No differences were documented for the concentration of the natriuretic peptides and CK-MB in accordance with the severity of clinical signs, but for cTnI a significant difference was reported when comparing asymptomatic and symptomatic animals. Also, the compromise of renal tubular function seemed to interfere with the concentration of the natriuretic peptides and cTnI. In conclusion, all cardiac-specific biomarkers were elevated when compared to the normal range previously proposed for dogs. Measuring specific cardiac biomarkers has the potential to non-invasively document myocardial injuries attributable to visceral leishmaniasis.