Wilson disease: copper deficiency and iatrogenic neurological complications with zinc therapy

Neurological complications due to copper deficiency in the context of Wilson disease treatment: a case report with long-term follow-up and review of the literature

The objective is to investigate the presentation, complications, management, and outcomes of copper deficiency-induced neurological pathologies due to Wilson disease (WD) overtreatment. We examined the case of a WD patient who developed a low thoracic dorsal myelopathy due to chronic hypocupremia from excessive zinc therapy. A comprehensive literature review was conducted to identify similar cases. Ten additional cases of neurological pathology resulting from copper deficiency in the context of WD over-treatment were identified, all occurring during therapy with zinc salts. Myelopathy and peripheral neuropathy were the most common complications, while two additional groups reported leukoencephalopathy. Early cytopenia was often associated with copper deficiency-related neurological pathology appearing early in the context of copper deficiency. WD patients undergoing treatment, especially with zinc salts, should be closely monitored to prevent over-treatment and the consequent copper deficiency. Regular complete blood counts could provide early detection of copper deficiency, avoiding irreversible neurological damage. Swift recognition of new neurological signs not consistent with WD and timely discontinuation of the decoppering therapy are critical for improving outcomes. The optimal management, including the potential benefit of copper supplementation in patients with WD and subsequent therapy adjustments, remains unclear and necessitates further investigation. Despite the general poor functional neurological outcomes, there were some exceptions that warrant further exploration.

Can Patients with Wilson's Disease Develop Copper Deficiency?

Background

Wilson's disease (WD) is a rare genetic condition characterized by a copper overload in organs secondary to mutation in ATP7B gene. Lifelong decoppering treatments are the keystone of the treatment but must be regularly adapted to obtain a correct copper balance and could lead to copper deficiency (CD).

Objectives

Study the characteristics of CD in WD patients.

Methods

CD cases from our cohort of 338 WD patients have been investigated. CD was defined by the association of serum copper, exchangeable copper and urinary copper excretion assays less than two standard deviations from the mean with cytopenia and/or neurological damage of spinal cord origin. A systematic review of literature about cases of CD in WD patient was performed in PubMed database according to PRISMA guidelines.

Results

Three WD patients were diagnosed with CD in our cohort. Review of the literature found 17 other patients. Most of the patients had anemia and neutropenia associated with neurological symptoms (especially progressive posterior cord syndrome). All the patients were treated with Zinc salts and the symptoms occurred more than a decade after the initiation of treatment. The adaptation of the treatment allowed a correction of the cytopenia but only a partial improvement of the neurological symptoms.

Conclusions

WD patients can develop CD after many years of zinc therapy. Anemia and neutropenia are red flags that should evoke CD.

Copper Deficiency as Wilson's Disease Overtreatment: A Systematic Review

BACKGROUND

Treatment of Wilson's disease (WD), an inherited disease characterized by copper overload, is lifelong and there is the possibility that copper deficiency (CD) may occur. We systematically reviewed the literature to describe treatment patterns, symptoms and outcomes associated with CD.

METHODS

Using preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, the PubMed database was searched up to 6 April 2023.

RESULTS

Across 17 articles, 20 cases of CD were described, most commonly (15 cases) in WD patients treated with zinc salts (ZS), less often on combined chelator and ZS therapy (3 cases), molybdate salts plus ZS (1), or molybdate alone (1). CD symptoms occurred insidiously, including sideroblastic anemia, neutropenia, axonal sensory neuropathy, posterior cord myelopathy and increased ratio of epileptic seizures (or epilepsy). CD diagnosis was based on symptoms and severely reduced urinary copper excretion (<20 µg/24 h [<0.3 µmol/24 h] on ZS, or <100 µg/24 h [<1.6 µmol/24 h] on chelators) with low total serum copper and ceruloplasmin.

CONCLUSIONS

Awareness of CD and regular monitoring of copper metabolism is needed during WD treatment. Temporary cessation of anti-copper treatment usually reverses serum copper reductions as well as pancytopenia; however, some symptoms, especially neuropathy and myelopathy, may persist.

Copper and Trace Elements in Gallbladder form Patients with Wilson's Disease Imaged and Determined by Synchrotron X-ray Fluorescence

Investigations about suspected tissue alterations and the role of gallbladder in Wilson’s disease (WD)—an inherited genetic disease with impaired copper metabolism—are rare. Therefore, tissue from patients with genetically characterised WD was investigated by microscopic synchrotron X-ray fluorescence (µSRXRF). For two-dimensional imaging and quantification of elements, X-ray spectra were peak-fitted, and the net peak intensities were normalised to the intensity of the incoming monochromatic beam intensity. Concentrations were calculated by fundamental parameter-based program quant and external standardisation. Copper (Cu), zinc (Zn) and iron (Fe) along with sulphur (S) and phosphorus (P) mappings could be demonstrated in a near histological resolution. All these elements were increased compared to gallbladder tissue from controls. Cu and Zn and Fe in WD-GB were mostly found to be enhanced in the epithelium. We documented a significant linear relationship with Cu, Zn and sulphur. Concentrations of Cu/Zn were roughly 1:1 while S/Cu was about 100:1, depending on the selected areas for investigation. The significant linear relationship with Cu, Zn and sulphur let us assume that metallothioneins, which are sulphur-rich proteins, are increased too. Our data let us suggest that the WD gallbladder is the first in the gastrointestinal tract to reabsorb metals to prevent oxidative damage caused by metal toxicity.

Cytopenia associated with copper deficiency

Introduction

Due to an increased incidence of copper deficiency, we investigated adult patients who had low serum levels of copper with cytopenia at our hospital from March 2014 to March 2021.

Methods

We retrospectively reviewed the clinical data of patients who had been diagnosed with cytopenia due to copper deficiency at the Aichi Medical University Hospital from March 2014 to March 2021.

Results

In the 15 patients with cytopenia secondary to low serum copper level, 11 had cytopenia of two to three lineages; three (27%) had pancytopenia, and eight (73%) had bicytopenia. Of the 15 patients, nine (60%) underwent bone marrow examinations; three (30%) showed typical morphologic features associated with copper deficiency, such as multiple clear cytoplasmic vacuoles in erythroblasts and myeloid cells, and three (30%) showed dysplastic features as observed in myelodysplastic syndrome. Among the 14 (93%) patients who were treated with copper supplements, had cessation of zinc supplements, or both, 11 (73%) and eight (53%) showed normal copper levels and hematological improvement, respectively.

Conclusion

Copper deficiency is more common than expected and should be considered in patients with unexplained cytopenia.

Nutraceuticals for Peripheral Vestibular Pathology: Properties, Usefulness, Future Perspectives and Medico-Legal Aspects

Vestibular disorders may generate complex signs and symptoms, which may alter patients' balance and the quality of life. Dizziness and vertigo can strongly affect daily activities and relations. Despite the presence of conventional drugs, maneuvers, and surgery, another interesting therapeutic opportunity is offered by nutraceuticals. These molecules are often used in the treatment of dizziness and vertigo, but the rationale of their application is not always solidly demonstrated by the scientific evidence. Several substances have shown a variable level of efficacy/usefulness in this field, but there is lack of important evidence for most of them. From a medico-legal point of view, specific information must be provided to the patient regarding the efficacy and possibilities that the use of these preparations can allow. Administering the right nutraceutical to the proper patient is a fundamental clinical skill. Integrating conventional drug treatment with nutraceutical administration seems to be easy, but it may be difficult considering the (in part unexplored) pharmacodynamics and pharmacokinetics of nutraceuticals. The aim of the scientific community should be to elevate nutraceuticals to the same law and technical dignity of conventional drugs.