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Background & Aims: In Wilson disease (WD), copper accumulation and increased non-ceruloplasmin-bound copper in plasma lead to liver and brain pathology. To better understand the fate of non-ceruloplasmin-bound copper, we used PET/CT to examine the whole-body distribution of intravenously injected 64-copper ( 64 Cu)., Methods: Eight patients with WD, five heterozygotes, and nine healthy controls were examined by dynamic PET/CT for 90 min and static PET/CT up to 20 h after injection. We measured 64 Cu activity in blood and tissue and quantified the kinetics by compartmental analysis., Results: Initially, a large fraction of injected 64 Cu was distributed to extrahepatic tissues, especially skeletal muscle. Thus, across groups, extrahepatic tissues accounted for 45-58% of the injected dose (%ID) after 10 min, and 45-55% after 1 h. Kinetic analysis showed rapid exchange of 64 Cu between blood and muscle as well as adipose tissue, with 64 Cu retention in a secondary compartment, possibly mitochondria. This way, muscle and adipose tissue may protect the brain from spikes in non-ceruloplasmin-bound copper. Tiny amounts of cerebral 64 Cu were detected (0.2%ID after 90 min and 0.3%ID after 6 h), suggesting tight control of cerebral copper in accordance with a cerebral clearance that is 2-3-fold lower than in muscle. Compared to controls, patients with WD accumulated more hepatic copper 6-20 h after injection, and also renal copper at 6 h., Conclusion: Non-ceruloplasmin-bound copper is initially distributed into a number of tissues before being redistributed slowly to the eliminating organ, the liver. Cerebral uptake of copper is extremely slow and likely highly regulated. Our findings provide new insights into the mechanisms of copper control., Impact and Implications: Maintaining non-ceruloplasmin-bound copper within the normal range is an important treatment goal in WD as this "free" copper is considered toxic to the liver and brain. We found that intravenously injected non-ceruloplasmin-bound copper quickly distributed to a number of tissues, especially skeletal muscle, subcutaneous fat, and the liver, while uptake into the brain was slow. This study offers new insights into the mechanisms of copper control, which may encourage further research into potential new treatment targets., Clinical Trial Number: 2016-001975-59., Competing Interests: The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2023 The Authors.)

(1) Introduction: Wilson's disease (WND) is an autosomal recessive disorder of copper (Cu) metabolism. Many tools are available to diagnose and monitor the clinical course of WND. Laboratory tests to determine disorders of Cu metabolism are of significant diagnostic importance. (2) Methods: A systematic review of the literature in the PubMed, Science Direct, and Wiley Online Library databases was conducted. (Results): For many years, Cu metabolism in WND was assessed with serum ceruloplasmin (CP) concentration, radioactive Cu test, total serum Cu concentration, urinary copper excretion, and Cu content in the liver. The results of these studies are not always unambiguous and easy to interpret. New methods have been developed to calculate non-CP Cu (NCC) directly. New parameters, such as relative Cu exchange (REC), reflecting the ratio of CuEXC to total serum Cu, as well as relative Cu exchange (REC), reflecting the ratio of CuEXC to total serum Cu, have been shown to be an accurate tool for the diagnosis of WND. Recently, a direct and fast LC-ICP-MS method for the study of CuEXC was presented. A new method to assess Cu metabolism during treatment with ALXN1840 (bis-choline tetrathiomolybdate [TTM]) has been developed. The assay enables the bioanalysis of CP and different types of Cu, including CP-Cu, direct NCC (dNCC), and labile bound copper (LBC) in human plasma. Conclusions: A few diagnostic and monitoring tools are available for patients with WND. While many patients are diagnosed and adequately assessed with currently available methods, diagnosis and monitoring is a real challenge in a group of patients who are stuck with borderline results, ambiguous genetic findings, and unclear clinical phenotypes. Technological progress and the characterization of new diagnostic parameters, including those related to Cu metabolism, may provide confidence in the more accurate diagnosis of WND in the future.

Introduction: The diagnosis of Wilson disease (WD) is plagued by biochemical and clinical uncertainties. Thus, calculated parameters have been proposed. This study aimed to: (a) compare the diagnostic values of non-caeruloplasmin copper (NCC), NCC percentage (NCC%), copper-caeruloplasmin ratio (CCR) and adjusted copper in WD; and (b) derive and evaluate a discriminant function in diagnosing WD., Methods: A total of 213 subjects across all ages who were investigated for WD were recruited. WD was confirmed in 55 patients, and the rest were WD free. Based on serum copper and caeruloplasmin values, NCC, NCC%, CCR and adjusted copper were calculated for each subject. A function was derived using discriminant analysis, and the cut-off value was determined through receiver operating characteristic analysis. Classification accuracy was found by cross-tabulation., Results: Caeruloplasmin, total copper, NCC, NCC%, CCR, adjusted copper and discriminant function were significantly lower in WD compared to non-WD. Discriminant function showed the best diagnostic specificity (99.4%), sensitivity (98.2%) and classification accuracy (99.1%). Caeruloplasmin levels <0.14 g/L showed higher accuracy than the recommended 0.20 g/L cut-off value (97.7% vs. 87.8%). Similarly, molar NCC below the European cut-off of 1.6 umol/L showed higher accuracy than the American cut-off of 3.9 umol/L (80.3% vs. 59.6%) (P < 0.001). NCC%, mass NCC, CCR and adjusted copper showed poorer performances., Conclusion: Discriminant function differentiates WD from non-WD with excellent specificity, sensitivity and accuracy. Performance of serum caeruloplasmin <0.14 g/L was better than that of <0.20 g/L. NCC, NCC%, CCR and adjusted copper are not helpful in diagnosing WD., Competing Interests: None

Wilson disease is a copper overload disease treatable with the chelators D-penicillamine and trientine to enhance urinary excretion or with zinc which predominantly inhibits absorption. By lifelong treatment a normal life expectancy and significant improvement of hepatic injury as well as neurologic manifestation is achievable. Here we evaluate the mode of action for effective therapy of Wilson disease. We postulate that there is no quantitative removal of copper from the liver possible. The therapeutic goal is the removal of toxic free copper (non-ceruloplasmin, but albumin bound copper). This is achievable by the induction of metallothionein which is accomplished by chelators and in particular by zinc. For control of therapy the option of a direct measurement of free copper would be preferable over the less reliable calculation of this fraction. A therapeutic challenge is still the full restoration of neurological deficits which can hardly be reached by the available chelators. Whether bis-choline-tetrathiomolybdate as intracellular copper chelator is an option has to be awaited. It is concluded that the goal of actual drug therapy in Wilson disease is the normalization of free copper in serum., Competing Interests: Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/atm-20-3090). The series “Unresolved Basic Issues in Hepatology” was commissioned by the editorial office without any funding or sponsorship. RW and Wolfgang Stremmel served as the unpaid Guest Editors of the series. RW serves as an unpaid editorial board member of Annals of Translational Medicine from Aug 2018–Jul 2022. The authors have no other conflicts of interest to declare., (2021 Annals of Translational Medicine. All rights reserved.)

Copper is a trace mineral that is essential to human health but can be harmful in excess. Since the introduction of copper-containing intrauterine devices in the 1970s, their possible relationship to abnormal/toxic blood copper levels has been researched. Here, we summarize and interpret 12 studies that evaluate blood copper levels in users of copper-containing intrauterine devices. The data are inconclusive, with the results of eight studies indicating no increase in blood copper levels with use and the results of four studies showing significant increases in blood copper levels with use. Investigators in all studies reviewed appear to have evaluated for total copper rather than free copper (the form of copper that is toxic), which raises questions about the clinical significance of all research on this subject to date., (Copyright © 2020 AWHONN. Published by Elsevier Inc. All rights reserved.)

The assay in serum of non-caeruloplasmin copper, as exchangeable copper after complexation with EDTA (ExCu) and total copper has been evaluated and compared in patients with varying c-reactive protein(CRP). Measurement of ExCu and total copper, range 0.2-47.2 µmol/L, was developed using ICP-MS. The chelating agents EDTA and TEPA were compared over 0.0-10 g/L after incubation with serum for 60 mins followed by ultrafiltration with Amicon 10 kDa filter. The assay for ExCu was optimised with EDTA 3 g/L (8.1 mmol/L) maintained at pH 7.0-8.0 before ultrafiltration. TEPA was not as selective in chelation of copper. Patients n  = 82 were studied in relation to changes in inflammatory marker CRP and a group of patients n  = 37 with normal CRP. The ExCu assay gave excellent recoveries (94-102 % but poor recovery for free uncomplexed copper), good repeatability, limit of quantitation 0.19 µmol/l with a provisional reference range 0.48 to 1.63 µmol/L ( n  = 37 patients). The range for relative exchangeable copper (exchangeable copper divided by total serum copper) was 2.49 to 9.96 %. ExCu was elevated in conditions with increased CRP greater than 100 mg/L suggesting an effect of inflammation on the free copper fraction. A reliable and reproducible assay for ExCu and total copper has been developed. The upregulated inflammatory state increases the ExCu suggesting excess free copper.

Background: Type 1 diabetes (T1D) is a chronic condition in which the pancreas loses the ability to produce insulin due to an autoimmune destruction of the insulin producing beta cells in the pancreatic islets of Langerhans. Pathophysiological complications related to diabetes include micro and macrovascular disease, nephropathy, and neuropathy that can also be affected by environmental factors such as lifestyle and diet., Objectives: The current study aimed to evaluate the serum levels of total copper, the copper-carrying protein, ceruloplasmin and nonceruloplasmin bound copper (nonceruloplasmin-Cu) and other essential and environmental metals and metalloids in subjects with T1D compared with healthy controls., Methods: A cohort of 63 subjects with T1D attending Diabetes Clinics at the University of Miami and 65 healthy control subjects was studied. Metals and metalloids were measured by inductively coupled plasma mass spectrometry., Results: A main finding of this study was that total copper and ceruloplasmin levels were higher in persons with T1D compared to healthy controls. In comparison to other metals and clinical variables, elevated copper was the strongest factor associated with T1D resulting in a15-fold increased odds of having the disease per standard deviation increase., Conclusion: Our results suggest a metal and metalloid perturbation in T1D with a significant involvement of Copper dysfunction in the disease pathology, possibly linked to inflammatory processes., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Background and Purpose: The severity of Wilson's disease (WD) is linked to free copper accumulating in the liver and brain. Exchangeable copper (CuEXC) is a new technique to determine plasmatic copper and is useful in the diagnosis of WD. It is hypothesized that it may also enable a good evaluation of extra-hepatic involvement and its severity., Methods: Forty-eight newly diagnosed WD patients were prospectively evaluated using hepatic, neurological, ophthalmological and brain magnetic resonance imaging (MRI) scores. Three phenotypic presentations were distinguished: pre-symptomatic, hepatic and extra-hepatic. CuEXC was determined in addition to standard copper assays before decoppering therapy. Correlations between biological parameters and the different scores were determined and compared in the hepatic and extra-hepatic groups., Results: Extra-hepatic patients had significantly higher CuEXC values than those with the hepatic form (P < 0.0001). The overall ability of CuEXC to separate the two forms was satisfactory, with an area under the curve of 0.883 (95% confidence interval 0.771-0.996) and an optimal threshold for extra-hepatic diagnosis of 2.08 μmol/l (sensitivity 85.7%; specificity 94.1%). In extra-hepatic patients, CuEXC was the only biological marker to be positively correlated with the Unified Wilson Disease Rating Score (r = 0.45, P = 0.016), the Kayser-Fleischer ring score (r = 0.46, P = 0.014) and the brain MRI score (r = 0.38, P = 0.048), but it was not correlated with the hepatic score., Conclusions: Exchangeable copper determination is useful when diagnosing WD as a value >2.08 μmol/l is indicative of the severity of the extra-hepatic involvement. In the case of purely hepatic presentation, atypical or mild neurological signs, it should encourage physicians to search for lesions in the brain and eyes., (© 2016 EAN.)

Background: Meta-analyses show that copper non-bound to ceruloplasmin (non-Cp Cu, also known as 'free' copper) in serum is higher in a percentage of Alzheimer's disease (AD) patients. Genetic heterogeneity in AD patients stratified on the basis of non-Cp Cu cut-off sustains the existence of a copper AD metabolic subtype., Objective: In order to find evidence of the existence of a detectable metabolic subtype of AD associated to copper abnormalities, we explore the hypothesis of a neuroimaging pattern heterogeneity in an homogenous and well characterized AD population classified in two groups by the stratification of patients on the basis non-Cp Cu cut-off., Method: We assessed levels of copper, ceruloplasmin, non-Cp Cu, cerebrospinal levels of total Tau protein (h-tau), Thr 181 phosphorylated tau protein (P-tau) and β-amyloid 1-42, and APOE4 genotype in 66 AD patients and compared neuroimaging indices of a visual rating scale of cerebral atrophy and neurovascular burden in AD patients stratified in 'Normal' and 'High' non-Cp Cu groups., Results: The stratification for non-Cp Cu originated AD groups which did not differ for medial temporal lobe atrophy, periventricular hyperintensities, deeper hyperintensities (including frontal, parietooccipital and temporal white matter hyperintensities), infratentorial hyperintensities indices, while they differed for global atrophy. More specifically, AD patients within the high non-Cp Cu group had a less severe burden of global atrophy (p=0.042)., Conclusion: This neuroimaging heterogeneity between AD groups is suggestive of the existence of a copper metabolic subtype of AD; non-Cp Cu appears a good marker of this copper AD., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Meta-analyses show that serum copper non-bound-to-ceruloplasmin (non-Cp-Cu) is higher in patients with Alzheimer's disease (AD). ATP7B gene variants associate with AD, modulating the size of non-Cp-Cu pool. However, a dedicated genetic study comparing AD patients after stratification for a copper biomarker to demonstrate the existence of a copper subtype of AD has not yet been carried out. An independent patient sample of 287 AD patients was assessed for non-Cp-Cu serum concentrations, rs1801243, rs1061472, and rs732774 ATP7B genetic variants and the APOE4 genotype. Patients were stratified into two groups based on a non-Cp-Cu cutoff (1.9 μM). Single-locus and haplotype-group analyses were performed to define their frequencies in dependence of the non-Cp-Cu group. The two AD subgroups did not differ regarding age, sex, MMSE score, or APOE4 frequency allele, while they did differ regarding non-Cp-Cu concentrations in serum, allele, genotype, and haplotype frequencies of rs1061472 A > G and rs732774 C > T after multiple testing corrections. AD patients with a GG genotype had a 1.76-fold higher risk of having a non-Cp-Cu higher than 1.9 μmol/L (p = 0.029), and those with a TT genotype for rs732774 C > T of 1.8-fold (p = 0.018). After 100,000 permutations for multiple testing corrections, the haplotype containing the AC alleles appeared more frequently in AD patients with normal non-Cp-Cu [43 vs. 33 %; Pm = 0.03], while the haplotype containing the GT risk alleles appeared more frequently in the higher non-Cp-Cu AD (66 vs. 55 %; Pm = 0.01). Genetic heterogeneity sustains a copper AD metabolic subtype; non-Cp-Cu is a marker of this copper AD.

Background: Defective copper regulation, primarily referred to as chelatable redox active Cu(II), has been involved in the etiology of diabetes, and Alzheimer's disease (AD)., Objectives: However, no study has determined levels of labile copper non-bound to ceruloplasmin (non-Cp Cu, also known as 'free' copper) in the blood of subjects with diabetes compared with that of AD patients., Methods: To this aim, values of non-Cp Cu were measured in 25 Type 1 (T1D) and 31 Type 2 (T2D) subjects and in28 healthy controls, along with measurements of C-reactive protein, glycated hemoglobin A1c, cholesterol, and triglycerides. Non-Cp Cu levels were compared with those of an AD group previously studied., Results: T2D subjects had significantly higher non-Cp Cu levels than Controls and T1D subjects (both p < 0.001 after adjusting for age, sex, and body mass index). A multinomial logistic model revealed that a one unit standard deviation increase of non-Cp Cu increased the relative risk of having T2D by 9.64 with respect to Controls (95% CI: 2.86-32.47). The comparison of non-Cp Cu levels in T2D with those of an AD population previously studied shows rising blood non-Cp Cu copper levels from Controls to T2D and AD., Conclusion: These results suggest the involvement of catalytically-active Cu(II) and glucose dysregulation in oxidative stress reactions leading to tissue damage in both diseases.

Alzheimer's disease is a multifactorial disease that is characterized mainly by Amyloid-β (A-β) deposits, cholinergic deficit and extensive metal (copper, iron)-induced oxidative stress. In this work we present details of the synthesis, antioxidant and copper-chelating properties, DNA protection study, cholinergic activity and amyloid-antiaggregation properties of new multifunctional tacrine-7-hydroxycoumarin hybrids. The mode of interaction between copper(II) and hybrids and interestingly, the reduction of Cu(II) to Cu(I) species (for complexes Cu-5e-g) were confirmed by EPR measurements. EPR spin trapping on the model Fenton reaction, using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap, demonstrated a significantly suppressed formation of hydroxyl radicals for the Cu-5e complex in comparison with free copper(II). This suggests that compound 5e upon coordination to free copper ion prevents the Cu(II)-catalyzed decomposition of hydrogen peroxide, which in turn may alleviate oxidative stress-induced damage. Protective activity of hybrids 5c and 5e against DNA damage in a Fenton system (copper catalyzed) was found to be in excellent agreement with the EPR spin trapping study. Compound 5g was the most effective in the inhibition of acetylcholinesterase (hAChE, IC50=38nM) and compound 5b was the most potent inhibitor of butyrylcholinesterase (hBuChE, IC50=63nM). Compound 5c was the strongest inhibitor of A-β1-40 aggregation, although a significant inhibition (>50%) was detected for compounds 5b, 5d, 5e and 5g. Collectively, these results suggest that the design and investigation of multifunctional agents containing along with the acetylcholinesterase inhibitory segment also an antioxidant moiety capable of alleviating metal (copper)-induced oxidative stress, may be of importance in the treatment of Alzheimer's disease., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Microalgae need a variety of nutrients for optimal growth and health. However, this rarely occurs in nature, and if nutrient proportions vary, biochemical changes can occur in phytoplankton community. This may result in modifications of zooplankton food quality, affecting aquatic food chains. Our aim was to investigate the toxicity of copper (Cu) to Selenastrum gracile, a common freshwater Chlorophyceae, at different physiological status induced by varying phosphorus (P) concentration in culture medium. Phosphorus was investigated at 2.3×10(-4), 1.1×10(-4), 2.3×10(-5), 4.6×10(-6) and 2.3×10(-6) mol L(-1) and Cu at six concentrations, ranging from 6.9×10(-9) mol L(-1) to 1.0×10(-7) mol L(-1) free Cu(2+) ions. To guarantee the cells would be in a physiological status that reflected the external P concentration, they were previously acclimated up to constant growth rate at each P concentration. Phosphorus acclimated cells were then exposed to Cu and toxicity was evaluated through population density, growth rates and chlorophyll a content. Free Cu(2+) ions concentrations were calculated through the chemical equilibrium model MINEQL(+). The results showed that higher Cu toxicity was obtained in P-limited than in P-replete cells, and that chlorophyll a/cell was higher in P-limited cells and excess Cu than in P-replete cells. This confirms the importance of microalgae nutritional status to withstand the negative effects of the trace metal., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Wilson disease is an inherited disorder of excessive copper accumulation. The commonly used drug d-penicillamine (PA) or trientine both cause a high incidence (10-50%) of neurological worsening, which rarely occurs with tetrathiomolybdate (TM) treatment. To investigate the mechanisms of neurologic deterioration after the initiation of chelation therapy, brain hydroxyl radical and free copper were assessed in vivo in this study. On days 3, 7, 14, and 21 after PA or TM administration, striatal hydroxyl radical levels of both TX mice and controls were assessed by terephthalic acid (TA) combined with microdialysis and high-performance liquid chromatography (HPLC). Within the same microdialysis samples, free copper was measured by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that both hydroxyl radical and free copper markedly increased in the striatum of TX mice during PA administration but were not elevated when administering TM. These results suggested that the further increased free copper in the brain and oxidative stress caused by some chelators might contribute to the neurological deterioration., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In a recent meta-analysis by Ventriglia and colleagues studying the association of zinc levels with Alzheimer's disease (AD), serum zinc has been found significantly decreased in AD patients compared with healthy controls. However, such a finding does not necessarily propose the causal role of low zinc in the pathophysiology of this neurodegenerative disease. On the basis of available evidence, free copper toxicosis may play a causal role in age-related AD, and zinc therapy can be a rational causal treatment. Nevertheless, a randomized controlled clinical trial testing a definite hypothesis is needed before conclusions can be drawn about the value of zinc supplements in the treatment of AD.

Wilson's disease (WD) is an inherited disorder of copper metabolism with main hepatic and neurological symptoms. Multiple sclerosis (MS) is an autoimmune and inflammatory demyelinating disease. We present two patients with coexisting WD and MS. In both cases the diagnosis of MS preceded diagnosis of WD. Both patients exhibited neurological signs typical of MS (internuclear palsy, optic neuritis). The first one displayed typical signs of WD (hypomimia, sialorrhea, behavioral changes). The second patient had liver injury without any neurological symptoms. In both cases clinical course of MS was very mild (17 and 12 years of observation) which may be caused by immunosuppressive effect of free copper., (Copyright © 2013 Elsevier B.V. All rights reserved.)