Comparison of N-terminal proB-type natriuretic peptide levels at different stages of visceral leishmaniosis and in patients with chronic kidney disease.

N-terminal proB-type natriuretic peptide (NT-proBNP) may be a useful marker in canine leishmaniosis (CanL). The aim was to compare NT-proBNP in dogs at different LeishVet stages of CanL and with idiopathic chronic kidney disease (CKD). Dogs diagnosed with CanL or CKD and a group of healthy dogs were included (group A, five normal dogs; group B, six dogs LeishVet 1-2; group C, 13 dogs LeishVet 3-4; group D, six dogs with CKD). NT-proBNP was higher (P<0.001) in group C (7.616 pmol/l, interquartile range (IQR) 3537-10,000 pmol/l) than in group A (293 pmol/l, IQR 257-373), group B (388.5 pmol/l, IQR 324-793) and group D (740 pmol/l, IQR 557-962 pmol/l). International Renal Interest Society (IRIS) kidney stage was not different between groups C and D or between groups A and B, but was different within all the rest of the group comparisons (P<0.001). In group C all dogs had echocardiographic increase in left ventricular mass index. NT-proBNP had negative correlation with haematocrit (P<0.001, r=0.749) and positive correlation with systemic blood pressure (P<0.001, r=0.728). NT-proBNP is consistently elevated in dogs with advanced CanL and is strongly correlated with the degree of systemic hypertension and anaemia. Moreover, dogs with advanced CanL exhibit increase in left ventricular mass. NT-proBNP may however be a less desirable cardiac marker as unlike cardiac troponin I it is often not elevated at earlier stages of CanL.