Tijl Vermassen1, Karen Geboes2, Marc De Man2, Stéphanie Laurent2, Elsie Decoene1, Nicolaas Lumen3, Joris Delanghe4, Sylvie Rottey1. 1. Department of Medical Oncology, Ghent University Hospital, Ghent, Belgium. 2. Department of Gastroenterology, Ghent University Hospital, Ghent, Belgium. 3. Department of Urology, Ghent University Hospital, Ghent, Belgium. 4. Department of Clinical Chemistry, Ghent University Hospital, Ghent, Belgium.
Abstract
Background: In the last decade, there has been an increase in the use of anti-angiogenic drugs as treatment for metastatic malignancies. However, use of these targeted therapies could induce both glomerular and tubular damage. Also during targeted therapy, the lysosomal protease cathepsin D is released from the tumour, which is inhibited by the protease inhibitor cystatin C. The aim of this study is to determine if use of cystatin C-estimated glomerular filtration rate (eGFR) is applicable to a patient cohort treated with targeted agents. Methods: A cohort of 80 patients with various malignancies were continuously recruited and prospectively analysed. Serum and urinary biochemical analytes for renal toxicities were assessed at different time points during treatment. The association between serum cystatin C and cathepsin D was also determined. Results: A decrease in serum cystatin C concentrations (1.03 versus 0.90 mg/L; P < 0.001), together with an increase in cystatin C-eGFR (71 versus 89 mL/min/1.73 m2; P = 0.002) was observed during therapy, compared with baseline. This decrease in cystatin C concentrations was correlated with cathepsin D (r = 0.307; P < 0.001), which was released from the tumour during targeted therapy. Further analysis demonstrated cathepsin D-mediated proteolysis of cystatin C in serum. Conclusions: Cystatin C concentrations were decreased during targeted therapy due to cathepsin D-mediated proteolysis. Cystatin C-eGFR is therefore not considered a suitable marker for assessing kidney function in oncology patients, and other techniques to estimate the GFR have to be applied in this patient population.
Background: In the last decade, there has been an increase in the use of anti-angiogenic drugs as treatment for metastatic malignancies. However, use of these targeted therapies could induce both glomerular and tubular damage. Also during targeted therapy, the lysosomal protease cathepsin D is released from the tumour, which is inhibited by the protease inhibitor cystatin C. The aim of this study is to determine if use of cystatin C-estimated glomerular filtration rate (eGFR) is applicable to a patient cohort treated with targeted agents. Methods: A cohort of 80 patients with various malignancies were continuously recruited and prospectively analysed. Serum and urinary biochemical analytes for renal toxicities were assessed at different time points during treatment. The association between serum cystatin C and cathepsin D was also determined. Results: A decrease in serum cystatin C concentrations (1.03 versus 0.90 mg/L; P < 0.001), together with an increase in cystatin C-eGFR (71 versus 89 mL/min/1.73 m2; P = 0.002) was observed during therapy, compared with baseline. This decrease in cystatin C concentrations was correlated with cathepsin D (r = 0.307; P < 0.001), which was released from the tumour during targeted therapy. Further analysis demonstrated cathepsin D-mediated proteolysis of cystatin C in serum. Conclusions: Cystatin C concentrations were decreased during targeted therapy due to cathepsin D-mediated proteolysis. Cystatin C-eGFR is therefore not considered a suitable marker for assessing kidney function in oncology patients, and other techniques to estimate the GFR have to be applied in this patient population.
Authors: M Joannidis; S J Klein; S John; M Schmitz; D Czock; W Druml; A Jörres; D Kindgen-Milles; J T Kielstein; M Oppert; V Schwenger; C Willam; A Zarbock Journal: Med Klin Intensivmed Notfmed Date: 2018-03-28 Impact factor: 0.840