RESEARCH COMMUNICATIONS OF THE 28th ECVIM-CA CONGRESS

Chronic kidney disease (CKD) is a common problem in feline practice. Early diagnosis can help to influence the outcome and improve the prognosis. Currently there are no reliable biomarkers for the early diagnosis of CKD. Since fibrosis is the main tissue alteration during CKD, we assumed that the transforming growth factor beta 1 (TGF‐ß1), an initiation molecule of tissue fibrosis may be used as an early indicator of CKD. The aim of this prospective study was to evaluate the diagnostic value of TGF‐β1 in feline CKD. Twenty‐five healthy cats and 26 cats with CKD were included in the study. TGF‐β1 was measured in serum using a “Quantikine Human TGF‐β1 Immunoassay” (R&D Systems). In healthy cats the median TGF‐β1 serum concentration was 27.37 ng/ml, while cats suffering from CKD had a median of 17.62 ng/ml, being the difference between both groups significant (p = 0.0013). CKD affected cats with International Renal Interest Society (IRIS) stage 2 had a median TGF‐β1 serum concentration of 14.82 ng/ml. Cats with IRIS stage 3 had a median of 15.79 ng/ml and cats with IRIS stage 4 had a median of 19.24 ng/ml. There was no significant correlation between the serum TGF‐β1 concentration and the different IRIS‐Stages. Furthermore there was no significant correlation between serum TGF‐β1 and the platelet count, even though these cells have the highest intracellular concentrations of TGF‐β1 in blood. Cats diagnosed with CKD showed lower serum TGF‐β1 concentrations than healthy cats. In another study serum TGF‐β1 was also higher in healthy cats compared to cats with CKD. A higher expression of TGF‐β1 in the kidneys accompanied by a higher synthesis of extracellular matrix can be detected histologically in humans. A missing rise of TGF‐β1 in serum of cats with CKD could be attributed to the fact that this cytokine is synthesised directly in the kidneys for local fibrosis processes. The possible use of serum TGF‐β1 as a diagnostic tool for CKD could not be validated in this study.