Urinary liver-type fatty acid-binding protein in cats with lower urinary tract disease

The aim of this study was to evaluate urinary liver-type fatty acid-binding protein levels in both obstructive and non-obstructive feline lower urinary tract disease. In addition, urinary liver-type fatty acid-binding protein levels were investigated in cats experiencing short-term (<36 hours) and long-term (≥36 hours) urethral obstruction.

The study included 32 cats, classified into two main groups: cats with feline lower urinary tract disease (n = 24) and healthy controls (n = 8). The feline lower urinary tract disease group was subdivided into obstructive (n = 16) and non-obstructive (n = 8) forms. The obstructive group was further divided based on urethral obstruction duration into short-term (n = 8) and long-term (n = 8) sub-subgroups. Serum creatinine, blood urea nitrogen and potassium were measured in blood samples. Urinary liver-type fatty acid-binding protein and urinary creatinine concentrations were measured in urine supernatant samples. Urinary liver-type fatty acid-binding protein concentrations were indexed to urinary creatinine and expressed as the urinary liver-type fatty acid-binding protein/creatinine ratio.

The mean urinary liver-type fatty acid-binding protein/creatinine values of cats with obstructive feline lower urinary tract disease were statistically higher than those in cats with non-obstructive feline lower urinary tract disease and healthy controls. The difference between the mean urinary liver-type fatty acid-binding protein/creatinine values of cats with long-term and short-term obstruction was not statistically significant. In addition, moderately positive correlations were calculated between urinary liver-type fatty acid-binding protein/creatinine and serum creatinine (r = .646; P < .001; 95% CI = 0.264 to 0.863) and between urinary liver-type fatty acid-binding protein/creatinine and blood urea nitrogen (r = .549; P < .01; 95% CI = 0.081 to 0.791) in the study population.

This study is the first to report urinary liver-type fatty acid-binding protein/creatinine in cats with feline lower urinary tract disease. The findings suggest that urinary liver-type fatty acid-binding protein/creatinine may serve as a potential biomarker for identifying post-renal acute kidney injury in cats with obstructive feline lower urinary tract disease, particularly in long-term obstructive cases.