Wilson disease: a summary of the updated AASLD Practice Guidance

Use of Estonian Biobank data and participant recall to improve Wilson's disease management

Population-based biobanks enable genomic screening to support initiatives that prevent disease onset or slow its progression and to estimate the prevalence of genetic diseases in the population. Wilson's disease (WD) is a rare genetic copper-accumulation disorder for which timely intervention is crucial, as treatment is readily available. We studied WD in the Estonian Biobank population to advance patient screening, swift diagnosis, and subsequent treatment. Combined analysis of genotype and phenotype data from electronic health records (EHRs) consolidated at the Estonian biobank led to the identification of 17 individuals at high risk of developing WD, who were recalled for further examination and deep phenotyping. All recall study participants, regardless of phenotype, age, and prior WD diagnosis, had low serum ceruloplasmin and copper levels, and 87% also exhibited signs of early to late neurodegeneration. The p.His1069Gln variant in ATP7B, a prevalent pathogenic mutation, showed a striking four- to five-fold enrichment in Estonians compared with other populations. Based on our analysis of genetic and nationwide health registry data, we estimate that WD remains underdiagnosed and undertreated in Estonia. Our study demonstrates that personalized medicine, implemented with the collaboration of medical professionals, has the potential to reduce the healthcare burden by facilitating the accurate diagnosis of rare genetic diseases. To our knowledge, this report is the first to describe a large-scale national biobank-based study of WD.

Trientine Tetrahydrochloride, From Bench to Bedside: A Narrative Review

Trientine tetrahydrochloride (TETA-4HCl, Cuvrior®) is a copper chelating agent with the active moiety triethylenetetramine (trientine), developed by Orphalan, Inc. to address the unmet needs in the treatment of Wilson disease. The journey from bench to bedside builds upon the documented safety profile of trientine hydrochloride capsules developed initially to meet the needs of individuals intolerant to D-penicillamine (DPA). Trientine hydrochloride capsules are inherently unstable requiring strict cold chain storage conditions from production, transportation, and use at home by the patient. Trientine tetrahydrochloride has a distinctive, patent-protected unique polymorphic form, which permits the production at scale of film-coated scored tablets deemed room temperature stable for 36 months. Trientine tetrahydrochloride is supported by a well-characterized pharmacodynamic, pharmacokinetic, and metabolic profile demonstrating reliable and predictable dose linearity and dose proportionality kinetics. Trientine tetrahydrochloride is the only trientine formulation that has been compared with DPA in a prospective randomized clinical trial, demonstrating non-inferiority to DPA in adults with stable Wilson disease. On 28 April, 2022, the US Food and Drug Administration approved TETA-4HCl for use in adult patients with Wilson disease who are de-coppered and tolerant to DPA. Health authorities in multiple countries worldwide have approved TETA-4HCl for the treatment of adults and children aged 5 years or more who are intolerant to DPA including the European Union, UK, Saudi Arabia, Switzerland, Colombia, Australia, New Zealand, and China. This article aims to provide a comprehensive narrative review of the key milestones in the development of TETA-4HCl.

Total Copper and Labile Bound Copper Fraction as a Selective and Sensitive Tool in the Evaluation of Wilson Disease

BACKGROUND

A dual filtration-based method for determination of serum labile bound copper (LBC) and LBC fraction (LBC/total copper) was developed. Reduced total copper, elevated LBC, and elevated LBC fraction have been reported in Wilson disease (WD).

METHODS

To evaluate the diagnostic performance of these markers, samples were obtained from 21 WD treatment-naïve (WD-TN, no WD treatment or <28 days of treatment) patients, 46 WD standard-of-care-treated (WD-SOC) patients, along with 246 patients representing other potential disorders of copper status. These were then compared to 213 reference interval population patients.

RESULTS

Receiver operating characteristic curves for the reference population vs WD-TN yielded areas under the curve for total copper, LBC, and LBC fraction, of 0.99, 0.81, and 0.98, respectively. Using Youden cutoffs, sensitivity/specificity for WD-TN was 95%/97% for total copper, 71%/85% for LBC, and 95%/94% for LBC fraction. LBC values, but not total copper and LBC fraction, differed substantially between WD-TN and WD-SOC cohorts.We propose a dual model wherein total copper and LBC fraction results must agree to be classified as a "positive" or "negative" result for WD. This correctly classified 19/21 WD-TN patients as positive, and 194/213 reference interval patients as negative. The remaining "indeterminate" patients (representing approximately 9% of the reference and the WD-TN populations) exhibited conflicting total copper and LBC fraction results. When indeterminate results are excluded, this model exhibited apparent 100% sensitivity/specificity.

CONCLUSIONS

Agreement of total serum copper and LBC fraction classification may constitute an effective "rule-in" and "rule-out" assessment for WD-TN patients.

Copper Toxicity in Animals: A Review

Copper is an essential trace element in animals and humans. However, excessive intake of copper can cause copper ions to accumulate in tissues and organs of animals, leading to copper toxicity. Copper ions induce apoptosis and autophagy through oxidative stress-mediated mitochondrial dysfunction. In addition, copper induces cell death by targeting lipoylated tricarboxylic acid (TCA) cycling proteins, termed cuproptosis. In recent years, copper cytotoxicity studies have attracted attention. In addition, the number of cases of copper toxicity in animals has been increasing over the past years due to environmental pollution and overdose from copper feed supplements. Therefore, a comprehensive understanding of copper toxicity and the metabolism of copper ions can aid in devising strategies for preventing copper toxicity. This review introduces the tissue and organ toxicity and cytotoxicity caused by copper toxicity and reviews the metabolism of copper ions in tissues, organs, and cells. The paper also reviews the clinical cases and animal experiments of copper toxicity in recent years. Finally, the preventive and curative measures for copper toxicity and the future challenges are also discussed. The general objective of this paper is to provide a reliable reference for copper toxicity prevention.

Copper, Iron, Cadmium, and Arsenic, All Generated in the Universe: Elucidating Their Environmental Impact Risk on Human Health Including Clinical Liver Injury

Humans are continuously exposed to various heavy metals including copper, iron, cadmium, and arsenic, which were specifically selected for the current analysis because they are among the most frequently encountered environmental mankind and industrial pollutants potentially causing human health hazards and liver injury. So far, these issues were poorly assessed and remained a matter of debate, also due to inconsistent results. The aim of the actual report is to thoroughly analyze the positive as well as negative effects of these four heavy metals on human health. Copper and iron are correctly viewed as pollutant elements essential for maintaining human health because they are part of important enzymes and metabolic pathways. Healthy individuals are prepared through various genetically based mechanisms to maintain cellular copper and iron homeostasis, thereby circumventing or reducing hazardous liver and organ injury due to excessive amounts of these metals continuously entering the human body. In a few humans with gene aberration, however, liver and organ injury may develop because excessively accumulated copper can lead to Wilson disease and substantial iron deposition to hemochromatosis. At the molecular level, toxicities of some heavy metals are traced back to the Haber Weiss and Fenton reactions involving reactive oxygen species formed in the course of oxidative stress. On the other hand, cellular homeostasis for cadmium and arsenic cannot be provided, causing their life-long excessive deposition in the liver and other organs. Consequently, cadmium and arsenic represent health hazards leading to higher disability-adjusted life years and increased mortality rates due to cancer and non-cancer diseases. For unknown reasons, however, liver injury in humans exposed to cadmium and arsenic is rarely observed. In sum, copper and iron are good for the human health of most individuals except for those with Wilson disease or hemochromatosis at risk of liver injury through radical formation, while cadmium and arsenic lack any beneficial effects but rather are potentially hazardous to human health with a focus on increased disability potential and risk for cancer. Primary efforts should focus on reducing the industrial emission of hazardous heavy metals.

Case report: Treatment of Wilson's disease by human amniotic fluid administration

Background

Wilson's disease (WD) is not an uncommon genetic disease in clinical practice. However, the current WD therapies have limitations. The effectiveness of stem cell therapy in treating WD has yet to be verified, although a few animal studies have shown that stem cell transplantation could partially correct the abnormal metabolic phenotype of WD. In this case report, we present the therapeutic effect of human amniotic fluid containing stem cells in one WD patient.

Case presentation

A 22-year-old Chinese woman was diagnosed with WD 1 year ago in 2019. The available drugs were not effective in managing the progressive neuropsychiatric symptoms. We treated the patient with pre-cultured human amniotic fluid containing stem cells. Amniotic fluid was collected from pregnant women who underwent induced labor at a gestational age of 19-26 weeks, and then, the fluid was cultured for 2 h to allow stem cell expansion. Cultured amniotic fluid that contained amniotic fluid derived stem cells (AFSC) in the range of approximately 2.8-5.5 × 104/ml was administrated by IV infusion at a rate of 50-70 drops per minute after filtration with a 300-mu nylon mesh. Before the infusion of amniotic fluid, low-molecular-weight heparin and dexamethasone were successively administrated. The patient received a total of 12 applications of amniotic fluid from different pregnant women, and the treatment interval depended on the availability of amniotic fluid. The neuropsychiatric symptoms gradually improved after the stem cell treatment. Dystonia, which included tremor, chorea, dysphagia, dysarthria, and drooling, almost disappeared after 1.5 years of follow-up. The Unified Wilson's Disease Rating Scale score of the patient decreased from 72 to 10. Brain magnetic resonance imaging (MRI) showed a reduction in the lesion area and alleviation of damage in the central nervous system, along with a partial recovery of the lesion to the normal condition. The serum ceruloplasmin level was elevated from undetectable to 30.8 mg/L, and the 24-h urinary copper excretion decreased from 171 to 37 μg. In addition, amniotic fluid transplantation also alleviates hematopoietic disorders. There were no adverse reactions during or after amniotic fluid administration.

Conclusion

Amniotic fluid administration, through which stem cells were infused, significantly improves the clinical outcomes in the WD patient, and the finding may provide a novel approach for managing WD effectively.

Ideal serum non-ceruloplasmin bound copper prediction for long-term treated patients with Wilson disease: a nomogram model

Purpose

This study aimed to explore the factors associated with the optimal serum non-ceruloplasmin bound copper (NCBC) level and develop a flexible predictive model to guide lifelong therapy in Wilson disease (WD) and delay disease progression.

Methods

We retrospectively collected clinical data from 144 patients hospitalized in the Encephalopathy Center of the first affiliated hospital of Anhui University of Chinese Medicine between May 2012 and April 2023. Independent variables were selected using variate COX and LASSO regressions, followed by multivariate COX regression analysis. A predictive nomogram was constructed and validated using the concordance index (C-index), calibration curves, and clinical decision curve analysis, of which nomogram pictures were utilized for model visualization.

Results

A total of 61 (42.36%) patients were included, with an average treatment duration of 55.0 (range, 28.0, 97.0) months. Multivariate regression analysis identified several independent risk factors for serum NCBC level, including age of diagnosis, clinical classification, laminin liver stiffness measurement, and copper to zinc ratio in 24-h urinary excretion. The C-index indicated moderate discriminative ability (48 months: 0.829, 60 months: 0.811, and 72 months: 0.819). The calibration curves showed good consistency and calibration; clinical decision curve analysis demonstrated clinically beneficial threshold probabilities at different time intervals.

Conclusion

The predictive nomogram model can predict serum NCBC level; consequently, we recommend its use in clinical practice to delay disease progression and improve the clinical prognosis of WD.