Decreased circulating transforming growth factor-beta (TGF-ß) and kidney TGF-ß immunoreactivity predict renal disease in cats with naturally occurring chronic kidney disease.

OBJECTIVES: The aim of the present study was to compare the circulating transforming growth factor-beta (TGF-ß) of clinically normal age-matched and naturally occurring chronic kidney disease (CKD) cats and to determine the correlation between the TGF-ß expression and histopathological changes in cats with CKD. METHODS: A total of 11 clinically normal age-matched and 27 cats with naturally occurring CKD were included in this study. Circulating TGF-ß was quantified by immunoassays. Kaplan-Meier analysis was used to calculate the association between survival time and the concentration of circulating TGF-ß. A general linear model was used to compare the circulating TGF-ß between groups. Immunohistochemical analyses revealed TGF-ß expression in renal tissues from cats with CKD that died during the study (n = 7) and in available archived renal tissue specimens taken at necropsy from cats that had previous CKD with renal lesions (n = 10). Correlations of the TGF-ß expression and clinical parameters (n = 7) and histopathological changes (n = 17) were analysed using Spearman's rank correlation. RESULTS: The median survival time of cats with a lower concentration of circulating TGF-ß was shorter than that of cats with a higher concentration. The area under the curve of circulating TGF-ß for predicting CKD was 0.781, indicating good differentiation. The study indicated a significant difference in circulating TGF-ß concentrations between clinically normal cats and those with CKD and demonstrated that TGF-ß expression is correlated with tubular atrophy. CONCLUSIONS AND RELEVANCE: The study findings suggest that decreased serum TGF-ß and tubular atrophy with TGF-ß immunoreactivity may be significant in cats with CKD.

Evaluation of Bcl-2 as a marker for chronic kidney disease prediction in cats.

Chronic kidney disease (CKD) is a frequent condition in elderly cats. Bcl-2 is linked to kidney disease through the processes of apoptosis and fibrosis. The purpose of this study is to examine Bcl-2 levels in CKD and clinically healthy age-matched cats in order to evaluate the relationship between Bcl-2 levels, signalment, and blood parameters in cats with CKD. The circulating levels of Bcl-2 were determined using an immunoassay in twenty-four CKD cats and eleven clinically healthy age-matched cats by the utilization of the general linear model (GLM), Pearson correlation, principal component analysis (PCA), ROC curves, the Cox hazard model, and Kaplan-Meier survival analysis. These were all conducted in order to explore Bcl-2 levels and their connection with other variables. The Bcl-2 immunohistochemical intensity was graded in each glomerulus and tubulointerstitium. McNemar's test was performed in order to compare the expression of Bcl-2 in the two renal tissue sites. The circulating Bcl-2 of CKD cats was significantly lower than those of clinically healthy age-matched cats (P = 0.034). The presence of circulating Bcl-2 (P < 0.01) and the severity of CKD (P = 0.02) were both linked with the survival time of cats with CKD. The area under the curve (AUC) of Bcl-2 for detection of CKD was 0.723. In cats, decreased circulating Bcl-2 was associated with increased blood BUN, creatinine levels, and CKD severity. Bcl-2 protein expression was reduced in the renal tissues of CKD cats as the disease progressed, resulting in a decrease in their survival time. This study demonstrated that Bcl-2 may be effective in diagnosing feline CKD.