Relationship between cytokeratins CK8/18&19 and KIM-1 level in urine with apoptosis and necrosis of nephrotheliocytes in rats with toxic nephropathy

The aim of the article. The aim of this work was to elucidate the role of apoptosis and necrosis in kidney tissue in the development of acute renal damage in poisoning rats with uranyl acetate. The research objectives included modeling acute poisoning in rats, collecting urine and kidney tissue with identifying markers of programmed cell death, tissue polypeptide antigen (TPA, fragments of cytokeratin CK8/18 19), and KIM-1 level in urine. An analysis of the relationship between an early increase in urinary excretion of the TPA and apoptosis level, a kidney injury molecule KIM-1, and necrosis of the tubular epithelial cells during rat poisoning with nephrotoxin uranyl acetate dihydrate. Materials and methods. Uranyl acetate dihydrate (CAS # 6159-44-0) was administered to 18-week old female Sprague-Dawley rats weighing 175199 g by intragastrically at a dose of 30 mg / 100 g body weight once through an atraumatic probe. Rats were divided into 2 groups: group 1 intact animals (12 individuals), group 2 animals with induced AKI (36 individuals). Daily urine was collected before, on the 1st, 3rd, and 7th day after poisoning in metabolic cages. The concentration of creatinine, KIM-1, tissue polypeptide antigen was measured in urine. In the kidney tissue samples, the fraction of dead cells and nephrothelial cells with apoptotic signs of nuclear changes by fluorescence microscopy with AMD Hoechst 33342 staining was determined. Data processing was performed using GraphPad Prism 6.0. Results. Acute kidney injury in rats with uranyl acetate dihydrate leads to a rapid increase in urinary excretion of cytokeratin fragments CK8/18 19 due to subtotal damage to nephrothelial cells due to activation of apoptosis, and then an increase in KIM-1 as a marker of necrotic cell death. Fluorescence microscopy of nuclear chromatin stained renal tubule cells showed a significant increase in the proportion of cells with apoptotic bodies, chromatin condensation, and a change in the shape of the nuclei. Conclusion. Examination of the curves of risk function showed that only creatinine in blood (p = 0.0002) and urine KIM-1 (p = 0.0005) had a significant level of association with rat mortality and necrosis of the nephrothelial cells. A comparative analysis of the relationship between apoptosis biomarker levels TPA (cytokeratin fragments CK8/18 19) and urinary nephrotoxicity marker KIM-1 with the proportion of kidney cells dying by the mechanism of necrosis and apoptosis revealed positive correlations of Spearman in pairs of cytokeratin CK8/18 19 apoptosis (r = 0.73, 95% CI 0.450.88, p 0.0001), KIM-1 necrosis (r = 0.98, 95% CI 0.960.99, p 0.0001). The revealed relationship indicated the possibility of determining urinary tissue polypeptide antigen TPA as a marker of the early stage of acute kidney damage as a surrogate marker of tubular cell apoptosis, and KIM-1 as a marker for necrosis of nephrothelial cells.

Predictive performance of TPA testing for recurrent disease during follow-up after curative intent surgery for colorectal carcinoma

Background:The aim of the present study was to investigate the predictive performance of serial tissue polypeptide antigen (TPA) testing after curative intent resection for detection of recurrence of colorectal malignancy.Methods:Serum samples were obtained in 572 patients from three different hospitals during follow-up after surgery. Test characteristics of serial TPA testing were assessed using a cut-off value of 75 U/L. The relation with American Joint Committee on Cancer stage and the potential additive value of tissue polypeptide antigen testing upon standard carcinoembryonic antigen (CEA) testing were investigated.Results:The area under the receiver operating characteristic curve of TPA for recurrent disease was 0.70, indicating marginal usefulness as a predictive test. Forty percent of cases that were detected by CEA testing would have been missed by TPA testing alone, whilst most cases missed by CEA were also not detected by TPA testing. In the subpopulation of patients with stage III disease predictive performance was good (area under the curve 0.92 within 30 days of diagnosing recurrent disease). In this group of patients, 86% of cases that were detected by CEA were also detected by TPA.Conclusions:Overall, TPA is a relatively poor predictor for recurrent disease during follow-up. When looking at the specific subpopulation of patients with stage III disease predictive performance of TPA was good. However, TPA testing was not found to be superior to CEA testing in this specific subpopulation.