Pseudokolinesteraza i pokazatelji oksidacijskoga stresa u djece s tumorskom bolešću u središnjem živčanom sustavu

Abstract

The aim of the study is to determine the activity of pseudocholinesterase (PChE) in serum and cerebrospinal fluid (CSF) and oxydative stress enzymes superoxide dismutase (SOD), catalase (CAT) and glutation peroxidase (GPx) in CSF and blood in children with solid central nervous system (CNS) tumor and to assess whether PChE activity and SOD, CAT and GPx could be a valid biomarker for solid CNS tumors in children. One of the final products of lipid peroxidation is malodialdehide (MDA) was determined too. Methods: The study and control group included 30 children each. Children in the study group had a solid CNS tumor, while those from the control group had never suffered from any tumor diseases. CSF and blood samples were collected from all participants. PChE activity was determined using the Ellman’s spectrophotometric method. GPx, SOD and CAT activity were measured spectrophotometrically; MDA with HPLC method. PChE activity in CSF was shown as a cerebrospinal fluid/serum ratio expressed in percentage, ie, PChE CSF/serum ratio. Receiver operating characteristic (ROC) curve was used to assess whether PChE activity, SOD, CAT and GPx can be used as a biomarker for identifying children with solid CNS tumors. Results: Children with solid CNS tumor had significantly higher PChE activity in CSF and serum, as well as PChE CSF/serum ratio (P= 0.001). PChE CSF/serum ratio in the study group was 2.38% (interquartile range [IQR] 1.14-3.97) and 1.09% (IQR 0.95-1.45) in the control group. ROC curve. analysis of PChE CSF/serum ratio resulted in an area under the curve (AUC) value of 0.76 (95% confidence interval [CI] 0.63-0.88) and a cut-off of 1.09. Twenty five of 29 patients with elevated PChE CSF/serum ratio had a tumor, corresponding to a sensitivity of 83% and a specificity of 53%. SOD, CAT, GPx and MDA in CSF have high specifity and sensitivity for the solid brain tumors in children and this study provide a cutt of values for the each of them. Between antioxidants highest sensitivity in plasma has SOD 84.62%; highest specifity has GPx 75%. In CSF highest sensitivity showed GPx 89.29%, highest specifity has SOD 100%. MDA sensitivity in brain tumor children in plasma is 80% and in CSF 70%. It’s specificity for plasma is 85.19% and in CSF 78.57%. SOD in plasma resulted in AUC 0,51 and in CSF 0,91; GPx in plasma 0,85 in CSF 0,93; CAT in plasma 0,69 and in CSF 0,90; MDA in plasma 0,89 in CSF 0,78. Conclusion: PChE CSF/serum ratio and SOD, CAT and GPx in CSF resulted in AUC from 0,80 to 0,93 and may be used as a biomarkers with good sensitivity and good or excellent tests for solid CNS tumors in children