Journal of Biosciences and Medicines, 2018, 6, 126-135 http://www.scirp.org/journal/jbm ISSN Online: 2327-509X ISSN Print: 2327-5081 Study of Xanthine Oxidase Activity in Sera of Iraqi Children with Nephrotic Syndrome Vyan Asad Qadir 1 , Sardar Nouri Ahmed 2* , Dler Rostum Ali 2 1 Department of Chemistry, Faculty of Science and Health, Koya University, Koy Sanjaq, Iraq 2 Department of Clinical Biochemistry, College of Medicine, Hawler Medical University, Erbil, Iraq Abstract Introduction: To investigate the relationship of xanthine oxidase activity with nephrotic syndrome disorder in children, and the optimization of the enzyme activity conditions in the disorder. Material and methods: Sera of children with nephrotic syndrome (NS) (60 samples) were obtained from Central Child Teaching Al Karama Hospital (CCTAH), from 2 nd Mar. 2013 to 28 th Feb. 2014. Sera of the patients were assayed for xanthine oxidase (XO) activity using colorimetric absorbance technique. The obtained results were compared with the enzyme activity of normal children (70 samples) as control. Results and conclusions: The results revealed a significant (P < 0.001) elevation in XO activity in serum of nephrotic syndrome (0.12 ± 0.06 IU/L) compared with that of normal subjects (0.05 ± 0.009 IU/L), showing an elevation of (70%) in XO activity (about 2/3) that of normal group. Factors influencing XO activities were also studied and showed that XO activity is a pH depen- dent. Significant elevation (P < 0.001) was found in uric acid level in sera of NS patients (497.52 ± 3.21 μmol/L) compared with that in normal group (298.12 ± 1.70 μmol/L). Elevation was found in urea level in sera of NS patient (10.69 ± 7.55 mmol/L) compared with that of normal group (4.57 ± 1.27 mmol/L). It was appeared, there is a role of XO activity in the pathogenesis of endothelial injury during glomerular lesion in NS and that was confirmed by comparing XO activity and other related conditions with the activity of nor- mal volunteers. Keywords Xanthine Oxidase, Urea, Uric Acid, Nephrotic Syndrome 1. Introduction Nephrotic syndrome (NS) is a collection of syndromes due to kidney damage. How to cite this paper: Qadir, V.A., Ahmed, S.N. and Ali, D.R. (2018) Study of Xanthine Oxidase Activity in Sera of Iraqi Children with Nephrotic Syndrome. Journal of Biosciences and Medicines, 6, 126-135. https://doi.org/10.4236/jbm.2018.65014 Received: March 27, 2018 Accepted: May 21, 2018 Published: May 24, 2018 Copyright © 2018 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access DOI: 10.4236/jbm.2018.65014 May 24, 2018 126 Journal of Biosciences and Medicines