Increased concentration of serum TNF alpha and its correlations with arterial blood pressure and indices of renal damage in dogs infected with Babesia canis.

Canine babesiosis is a tick-borne disease caused by parasites of the genus Babesia. Tumour necrosis factor alpha (TNF-α) is a cytokine that plays a role in the pathogenesis of canine babesiosis. In this study, the authors determined the concentration of serum TNF-α in 11 dogs infected with Babesia canis and calculated Spearman's rank correlations between the concentration of TNF-α and blood pressure, and between TNF-α and indices of renal damage such as: fractional excretion of sodium (FE(Na(+))), urinary creatinine to serum creatinine ratio (UCr/SCr), renal failure index (RFI), urine specific gravity (USG) and urinary protein to urinary creatinine ratio (UPC). The results demonstrated statistically significant strong negative correlations between TNF-α and systolic arterial pressure (r = -0.7246), diastolic arterial pressure (r = -0.6642) and mean arterial pressure (r = -0.7151). Serum TNF-α concentration was also statistically significantly correlated with FE(Na(+)) (r = 0.7056), UCr/SCr (r = -0.8199), USG (r = -0.8075) and duration of the disease (r = 0.6767). The results of this study show there is an increase of serum TNF-α concentration during canine babesiosis, and the increased TNF-α concentration has an influence on the development of hypotension and renal failure in canine babesiosis. This probably results from the fact that TNF-α is involved in the production of nitric oxide and induction of vasodilation and hypotension, which may cause renal ischaemia and hypoxia, and finally acute tubular necrosis and renal failure.