Author information
1Liver Unit, Hospital Clínic, IDIBAPS, CIBERehd, Barcelona, Spain.
2Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona (UB), Barcelona, Spain.
3European Reference Network on Rare Liver Disorders (ERN-RARE Liver), Hospital Clinic Barcelona, Barcelona, Spain.
4Department of Pediatric Gastroenterology, Hepatology and Nutrition, Hospital Sant Joan de Deu, Barcelona, Spain.
5Comprehensive Unit of Complex Hepatology and Pediatric Liver Transplantation (Hospital Sant Joan de Deu and Hospital Vall d'Hebron), Barcelona, Spain.
6Biochemistry and Molecular Genetics Unit, Hospital Clínic, CIBERER and IDIBAPS, Barcelona, Spain.
7Pediatric Hepatology and Liver Transplant Unit, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
8European Reference Network on Rare Liver Disorders (ERN-Liver), Metabolic Hereditary Disorders (MetabERN) and Transplantation in Children (Transplant Child), Hospital Universitari Vall d'Hebron, Barcelona, Spain.
9Clinical Biochemistry Department, Institut de Recerca Sant Joan de Deu, and CIBERER, Barcelona, Spain.
Abstract
Wilson disease (WD) is a complex disease in which diagnosis and long-term metabolic copper control remains challenging. The absence of accurate biomarkers requires the combination of different parameters to ensure copper homeostasis. Exchangeable copper and its ratio (REC) have been suggested to be useful biomarkers in this setting. We aimed at introducing these measurements and evaluate their performance and accuracy in our real-world cohort of WD patients. Exchangeable copper and REC were measured in 48 WD patients and 56 control individuals by inductively coupled plasma-mass-spectrometry. Demographic and clinical characteristics were collected. REC was shown to be significantly higher among WD patients compared to controls and useful for WD identification by using the previously established cutoffs: 71.4% of WD patients with a recent diagnosis had REC ≥18.5% and 95.1% of long-term treated WD had REC ≥14%; only four patients of the cohort presented discordant levels. Moreover, REC values were below 15% in all the control individuals. Exchangeable copper was significantly higher in WD patients compared to controls and tended to be reduced among WD patients who were compliant to medication. This real-life study confirmed that exchangeable copper and REC are useful serum biomarkers that can be used as complementary tests to ensure WD diagnosis (REC) and copper homeostasis whithin time (exchangeable copper). The desirable target levels for this last objective still needs to be validated in prospective cohorts.