Survey of urinary nickel in peritoneal dialysis patients

// Ya-Ching Huang 1, 2, * , Hsiao-Chen Ning 1, 2, * , Shang-Syuan Chen 1 , Chia-Ni Lin 1, 2 , I-Kwan Wang 3 , Shu-Man Weng 4 , Cheng-Hao Weng 4 , Ching-Wei Hsu 4 , Wen-Hung Huang 4 , Jang-Jih Lu 1 , Tsu-Lan Wu 1, 2 and Tzung-Hai Yen 4, 5, 6 1 Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan 2 Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Linkou, Taiwan 3 Department of Nephrology, Chang Medical University Hospital and College of Medicine, China Medical University, Taichung, Taiwan 4 Department of Nephrology, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Linkou, Taiwan 5 Kidney Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan 6 Center for Tissue Engineering, Chang Gung Memorial Hospital, Linkou, Taiwan * These authors have contributed equally to this work Correspondence to: Tzung-Hai Yen, email: m19570@adm.cgmh.org.tw Keywords: peritoneal dialysis, nickel, high sensitivity C-reactive protein, inflammation, inductively coupled plasma mass spectrometry Received: May 14, 2017     Accepted: June 30, 2017     Published: July 31, 2017 ABSTRACT This study surveyed urinary nickel concentrations in peritoneal dialysis (PD) patients, and analyzed the association of urinary nickel concentrations with clinical outcomes and inflammatory biomarkers. In total, 50 PD patients and 50 healthy controls were recruited for this study. All participants were examined for the presence of toxic trace elements (antimony, arsenic, bismuth, cadmium, copper, manganese, mercury, nickel, lead, tellurium, thallium and zinc) in their urine by using inductively coupled plasma mass spectrometry (ICP-MS). It was found that PD patients demonstrated higher urinary nickel concentrations than healthy controls (6.1±3.5 versus 2.8±1.4 μg/L, P<0.001). There were 24 (48.0%) PD patients with normal urinary nickel concentrations, and 26 (52.0%) PD patients with high urinary nickel concentrations. The PD patients with high urinary nickel concentrations demonstrated higher log serum levels of high sensitivity C-reactive protein (0.4±0.5 versus 0.1±0.5 mg/L, P=0.046) than patients with normal urinary nickel concentrations. Furthermore, patients with high urinary nickel concentrations exhibited higher levels of cadmium (1.3±0.9 versus 0.6±0.5 μg/L, P<0.001), copper (7.7±5.7 versus 3.3±1.4 μg/L, P<0.001) and manganese (0.9±1.1 versus 0.4±0.4 μg/L, P=0.023) than patients with normal urinary nickel concentrations. Nevertheless, there were no significant differences in the clinical outcomes between PD patients with high and normal urinary nickel concentrations (P>0.05). Thus, it is concluded that approximately half of the patients undergoing PD had elevated urinary nickel levels, and these patients also had elevated serum levels of high sensitivity C-reactive protein. Nevertheless, no other real correlations were discovered including no impact on patient outcome. Further studies are warranted.