Research of new biomarkers in body fluids to detect the primary problem is crucial in human and veterinary medicine. Although serum choline is suggested as emerging biomarkers in humans and dogs with myocardial ischemia, there is no available data on usefulness of choline levels for predicting cardiac events. Therefore, this study was aimed to evaluate the use of choline concentration as a potential biomarker for distinguishing pleural effusions due to heart base tumours (HBT) and dilated cardiomyopathy (DCM), and determine whether there was a correlation between pleural and serum choline levels in dogs.

Dogs with pleural effusion due to DCM (n=11) and HBT (n=8) were used as materials. Pleural effusions were diagnosed by clinical, radiological, and ultrasonographic (US) examinations along with US-guided thoracentesis. DCM was diagnosed based on the sum of the scores (=>6 points) recommended by European Society of Veterinary Cardiology taskforce. Pre-operative diagnosis of HBTs was confirmed by histopathological evaluations showing mesothelioma, chemodectoma, hemangiosarcoma, and aortic body tumours. Healthy age- and breed-matched dogs (n=10) were used as controls. Serum free-choline concentration of each sample was analyzed by high performance liquid chromatography in triplicate and results were expressed as micromolar (µM).

Serum choline concentrations in dogs were (median [range]) 14.8 (6.5–19.2) µM for healthy dogs, 14.7 (7.9–28.4) µM for DCM and 8.7 (5.0–13.9) µM for HBTs (but not significant between groups). There was a statistically significant difference (p<0.05) on choline concentration (Mean ± SEM) in pleural fluids between dogs with DCM and HBTs; 13.5 ± 3.9 µM and 23.1 ± 8.5 µM, respectively. Choline level was higher (p<0.05) in pleural fluid, compared to that of serum in dogs with HBTs, whereas there was not statistically significant difference between them in dogs with DCM. In all dogs (n=19), choline level in pleural effusions (24.9 ± 6.3 µM) was higher (p<0.001) than its serum level (10.6 ± 1.2 µM). There were no significant relationships (Pearson correlation) between choline levels in serum and pleural fluids in dogs with DCM and HBT.

These data suggest that pleural fluid choline concentration, rather than its serum concentration, might be used as a new potential biomarker for distinguishing from DCM and HBTs in dogs.

Disclosures

No disclosures to report.