NU03 - Urine Active Transforming Growth Factor-Beta Concentrations in Cats with Ureteral Obstruction

Abstract: Background - Urinary active transforming growth factor-beta (uaTGF-β1) correlates with inflammation and fibrosis in chronic kidney disease (CKD), but its utility as a biomarker in ureteral obstruction (UO) has not been studied. Hypothesis - uaTGF-β1 would be increased in cats with UO, and higher in cats that remain azotaemic following subcutaneous ureteral bypass (SUB) placement compared to those that become non-azotaemic. Animals - Twenty-five cats with UO and subsequent SUB placement and 22 control cats matched to UO cases by post-operative creatinine concentration at the first SUB flush appointment. Methods - Retrospective, observational, cross-sectional study comparing uaTGF-β1 concentrations (indexed to urine creatinine; uaTGF-β1:Cr, pg/mg) at obstruction (cystocentesis, pyelocentesis, or both) in cats with UO to controls. Additionally, uaTGF-β1 in cats with UO were compared between those that remained azotaemic and those that became non-azotaemic following SUB placement. Comparisons used the Mann-Whitney U test. Data are median [IQR]. Results - uaTGF-β1 was significantly higher in cats with UO (54.19pg/mg [46.46]; n = 15) compared to controls (17.78pg/mg [18.43]; p = 0.0065; n = 15). uaTGF-β1 in samples taken by pyelocentesis from cats with UO (48.22pg/mg [87.51]; n = 18) did not differ significantly from cystocentesis samples from control cats (20.09pg/mg [25.29]; n = 18; p = 0.083). uaTGF-β1 did not differ between cats that were azotaemic (n = 9) and non-azotaemic (n = 5; 56.66pg/mg [36.16] vs 29.89pg/mg [111.08]; p = > 0.99) at follow-up. Conclusion and Clinical Importance - Study of TGF-β1 modulation in recovery from UO is warranted.