Copper-associated chronic hepatitis in Cavalier King Charles spaniels

BACKGROUND

Copper-associated chronic hepatitis (CuCH) is poorly characterised in Cavalier King Charles spaniels (CKCS).

METHODS

Hepatic copper accumulation was qualitatively and quantitatively assessed, and blood samples were used for genetic testing to screen for known CuCH-associated genetic variants.

RESULTS

The study included 13 CKCS with CuCH and eight unaffected controls. Increased transaminase activities, elevated biliary enzyme concentrations and portal hypertension were documented in 100%, 73% and 38% of dogs with CuCH, respectively. Five dogs had three or more abnormalities in measures of liver function. All 11 dogs with CuCh that underwent genetic testing were homozygous negative for the COMMD1 deletion and ATP7A variant but homozygous positive (n = 7) or heterozygous (n = 4) for the ATP7B variant. Liver histology often demonstrated marked architectural distortion by severe, bridging fibrosis and regenerative nodules with lymphoplasmacytic inflammation. Centrilobular copper accumulation characterised early cases with minimal fibrosis. When fibrosis was significant, copper was often differentially concentrated within regenerative nodules. Chelation therapy resolved laboratory derangements and portal hypertension in five of seven dogs. Of the 7 non-surviving dogs with CuCH, 6 had not received chelation therapy.

LIMITATIONS

Limitations include a small cohort size and the lack of pedigree analyses to corroborate heritability.

CONCLUSIONS

CuCH should be considered in CKCS with suspected liver disease. Long-term prognosis seems favourable in dogs receiving chelation therapy, notwithstanding the presence of previously reported negative prognostic markers.

Construction and Application of an Electrochemical Sensor for Determination of D-Penicillamine Based on Modified Carbon Paste Electrode

D-penicillamine (D-PA) is a sulfur-containing drug that has been used for various health conditions. However, like any medication, overdosing on D-PA can have adverse effects and may require additional treatment. Therefore, developing simple and sensitive methods for sensing D-PA can play a crucial role in improving its efficacy and reducing its side effects. Sensing technologies, such as electrochemical sensors, can enable accurate and real-time measurement of D-PA concentrations. In this work, we developed a novel electrochemical sensor for detecting D-PA by modifying a carbon paste electrode (CPE) with a multi-walled carbon nanotube-Co3O4 nanocomposite, benzoyl-ferrocene (BF), and ionic liquid (IL) (MWCNT-Co3O4/BF/ILCPE). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CHA) were employed to explore the electrochemical response of D-PA on the developed sensor, the results of which verified a commendable electrochemical performance towards D-PA. Under optimized conditions, the developed sensor demonstrated a rapid response to D-PA with a linear dynamic range of 0.05 μM-100.0 μM, a low detection limit of 0.015 μM, and a considerable sensitivity of 0.179 μA μM-1. Also, the repeatability, stability, and reproducibility of the MWCNT-Co3O4/BF/ILCPE sensor were studied and showed good characteristics. In addition, the detection of D-PA in pharmaceutical and biological matrices yielded satisfactory recoveries and relative standard deviation (RSD) values.

Challenges and dilemmas in pediatric hepatic Wilson's disease

Wilson disease is an autosomal recessive disorder affecting the ATP7B gene located on chromosome 13q. This leads to copper deposition in various organs, most importantly in the liver and brain. The genetic mutations are vast, well reported in the West but poorly documented in developing countries. Hence the diagnosis is made with a constellation of clinico-laboratory parameters which have significant overlap with other liver diseases and often pose a significant dilemma for clinicians. Diagnostic scoring systems are not fool-proof. The availability and affordability of chelators in developing countries impact the drug compliance of patients. While D-penicillamine is a potent drug, its side effects lead to drug discontinuation. Trientine is cost-prohibitive in developing countries. There is no single test to assess the adequacy of chelation. Exchangeable urinary copper is an essential upcoming diagnostic and prognostic tool. In the presence of cirrhosis, hypersplenism clouds the assessment of myelosuppression of drugs. Similarly, it may be difficult to distinguish disease tubulopathy from drug-induced glomerulonephritis. Neurological worsening due to chelators may appear similar to disease progression. Presentation as fulminant hepatic failure requires rapid workup. There is a limited window of opportunity to salvage these patients with the help of plasmapheresis and other liver-assisted devices. This review addresses the challenges and clinical dilemmas faced at beside in developing countries.

Significant heterogeneity in the diagnosis and long-term management of Wilson disease: Results from a large multicenter Spanish study

There is uncertainty regarding Wilson's disease (WD) management.

OBJECTIVES

To assess, in a multicenter Spanish retrospective cohort study, whether the approach to WD is homogeneous among centers.

METHODS

Data on WD patients followed at 32 Spanish hospitals were collected.

RESULTS

153 cases, 58% men, 20.6 years at diagnosis, 69.1% hepatic presentation, were followed for 15.5 years. Discordant results in non-invasive laboratory parameters were present in 39.8%. Intrahepatic copper concentration was pathologic in 82.4%. Genetic testing was only done in 56.6% with positive results in 83.9%. A definite WD diagnosis (Leipzig score ≥4) was retrospectively confirmed in 92.5% of cases. Chelating agents were standard initial therapy (75.2%) with frequent modifications (57%), particularly to maintenance zinc. Enzyme normalization was not achieved by one third, most commonly in the setting of poor compliance, lack of genetic mutations and/or presence of cardiometabolic risk factors. Although not statistically significant, there were trends for sex differences in number of diagnosed cases, age at diagnosis and biochemical response.

CONCLUSIONS

Significant heterogeneity in diagnosis and management of WD patients emerges from this multicenter study that includes both small and large reference centers. The incorporation of genetic testing will likely improve diagnosis. Sex differences need to be further explored.

Synthesis and Characterization of Gold Chiral Nanoparticles Functionalized by a Chiral Drug

Inorganic chiral nanoparticles are attracting more and more attention due to their peculiar optical properties and potential biological applications, such as bioimaging, therapeutics, and diagnostics. Among inorganic chiral nanoparticles, gold chiral nanostructures were demonstrated to be very interesting in this context, with good physical chemical stability and also the possibility to decorate the surface, improving biomedical application as the interaction with the bio-systems. Gold (Au) nanostructures were synthesized according to a seed-mediated procedure which envisages the use of cetyltrimethylammonium bromide (CTAB) as the capping agent and L- and D-cysteine to promote chirality. Au nanostructures have been demonstrated to have opposite circular dichroism signals depending on the amino acid enantiomer used during the synthesis. Then, a procedure to decorate the Au surface with penicillamine, a drug used for the treatment of Wilson's disease, was developed. The composite material of gold nanoparticles/penicillamine was characterized using electron microscopy, and the penicillamine functionalization was monitored by means of UV-Visible, Raman, and infrared spectroscopy, highlighting the formation of the Au-S bond. Furthermore, electron circular dichroism was used to monitor the chirality of the synthesized nanostructures and it was demonstrated that both penicillamine enantiomers can be successfully bonded with both the enantiomers of the gold nanostructures without affecting gold nanoparticles' chirality. The effective modification of nanostructures' surfaces via penicillamine introduction allowed us to address the important issue of controlling chirality and surface properties in the chiral nano-system.

Development of Polydiphenylamine@Electrochemically Reduced Graphene Oxide Electrode for the D-Penicillamine Sensor from Human Blood Serum Samples Using Amperometry

D-penicillamine (PA) is a sulfur group-containing drug prescribed for various health issues, but overdoses have adverse effects. Therefore, regular, selective, and sensitive sensing is essential to reduce the need for further treatment. In this study, diphenylamine (DPA) was electropolymerized in an aqueous acidic medium. The PA detection sensitivity, selectivity, and limit of detection were enhanced by electropolymerizing DPA on an electrochemically reduced graphene oxide (ERGO)/glassy carbon (GC) surface. The formation of p-DPA and ERGO was investigated using various techniques. The as-prepared p-DPA@ERGO/GC revealed the excellent redox-active (N-C to N=C) sites of p-DPA. The p-DPA@ERGO/GC electrode exhibited excellent electrochemical sensing ability towards PA determination because of the presence of the -NH-functional moiety and effective interactions with the -SH group of PA. The p-DPA@ERGO/GC exhibited a high surface coverage of 9.23 × 10^-12 mol cm^-2. The polymer-modified p-DPA@ERGO/GC electrode revealed the amperometric determination of PA concentration from the 1.4 to 541 μM wide range and the detection limit of 0.10 μM. The real-time feasibility of the developed p-DPA@ERGO/GC electrode was tested with a realistic PA finding in human blood serum samples and yielded a good recovery of 97.5-101.0%, confirming the potential suitability in bio-clinical applications.

Effect of Copper Chelators via the TGF-β Signaling Pathway on Glioblastoma Cell Invasion

Glioblastoma multiforme (GBM) is a fast-growing and aggressive type of brain cancer. Unlike normal brain cells, GBM cells exhibit epithelial-mesenchymal transition (EMT), which is a crucial biological process in embryonic development and cell metastasis, and are highly invasive. Copper reportedly plays a critical role in the progression of a variety of cancers, including brain, breast, and lung cancers. However, excessive copper is toxic to cells. D-penicillamine (DPA) and triethylenetetramine (TETA) are well-known copper chelators and are the mainstay of treatment for copper-associated diseases. Following treatment with copper sulfate and DPA, GBM cells showed inhibition of proliferation and suppression of EMT properties, including reduced expression levels of N-cadherin, E-cadherin, and Zeb, which are cell markers associated with EMT. In contrast, treatment with copper sulfate and TETA yielded the opposite effects in GBM. Genes, including TGF-β, are associated with an increase in copper levels, implying their role in EMT. To analyze the invasion and spread of GBM, we used zebrafish embryos xenografted with the GBM cell line U87. The invasion of GBM cells into zebrafish embryos was markedly inhibited by copper treatment with DPA. Our findings suggest that treatment with copper and DPA inhibits proliferation and EMT through a mechanism involving TGF-β/Smad signaling in GBM. Therefore, DPA, but not TETA, could be used as adjuvant therapy for GBM with high copper concentrations.

Epidemiology, treatment and burden of Wilson disease in France: A 10-year analysis of the national health insurance database

BACKGROUND & AIMS

Wilson disease (WD) is a rare hereditary, debilitating disease that is fatal if untreated. Given its low prevalence, collecting longitudinal information on large cohorts of patients is challenging. Analysis of health insurance databases offers an approach to meet this challenge. The aim of this study was to evaluate longitudinal trends in the presentation and management of patients with WD identified in the French national health insurance database (SNDS).

METHODS

This retrospective, longitudinal, observational study identified people with WD in the SNDS database through hospitalisation diagnosis codes and long-term illness status between 2009 and 2019 inclusive. For each patient, data were extracted on hospitalisations, liver transplantation, mortality, WD-specific treatments (d-penicillamine, trientine and zinc), disability status and sick leave.

RESULTS

1,928 patients with WD were identified, of whom 1,520 (78.8%) were analysed. Prevalence of WD in 2019 was estimated as 2.2 cases per 100,000. Of the 670 patients first documented between 2010 and 2019, 76.1% were hospitalised at least once for a mean duration of 4.63±10.6 days. 152 patients (10.0%) underwent liver transplantation and 205 died (13.5%). The mean age at death was 57.9 ± 23.1 years. 665 patients (43.8%) received a WD-specific treatment at least once. 167 patients (17.1%) received a government disability pension and 624 (41.1%) benefited from long-term illness status due to WD.

CONCLUSIONS

Unexpectedly, less than half of patients with WD received treatment recommended in practice guidelines, which may contribute to a high disease burden in terms of hospitalisations, disability and reduced life expectancy. Improving treatment rates, building patient awareness of long-term disease impact or developing a new paradigm of treatment could make a significant contribution to reducing the disease burden.

Copper Modulates Adult Neurogenesis in Brain Subventricular Zone

The subventricular zone (SVZ) in lateral ventricles is the largest neurogenic region in adult brain containing high amounts of copper (Cu). This study aims to define the role of Cu in adult neurogenesis by chelating labile Cu ions using a well-established Cu chelator D-Penicillamine (D-Pen). A neurosphere model derived from adult mouse SVZ tissues was established and characterized for its functionality with regards to neural stem/progenitor cells (NSPCs). Applying D-Pen in cultured neurospheres significantly reduced intracellular Cu levels and reversed the Cu-induced suppression of NSPC’s differentiation and migration. An in vivo intracerebroventricular (ICV) infusion model was subsequently established to infuse D-Pen directly into the lateral ventricle. Metal analyses revealed a selective reduction of Cu in SVZ by 13.1% (p = 0.19) and 21.4% (p < 0.05) following D-Pen infusions at low (0.075 μg/h) and high (0.75 μg/h) doses for 28 days, respectively, compared to saline-infused controls. Immunohistochemical studies revealed that the 7-day, low-dose D-Pen infusion significantly increased Ki67(+)/Nestin(+) cell counts in SVZ by 28% (p < 0.05). Quantification of BrdU(+)/doublecortin (DCX)(+) newborn neuroblasts in the rostral migration stream (RMS) and olfactory bulb (OB) further revealed that the short-term, low-dose D-Pen infusion, as compared with saline-infused controls, resulted in more newborn neuroblasts in OB, while the high-dose D-Pen infusion showed fewer newborn neuroblasts in OB but with more arrested in the RMS. Long-term (28-day) infusion revealed similar outcomes. The qPCR data from neurosphere experiments revealed altered expressions of mRNAs encoding key proteins known to regulate SVZ adult neurogenesis, including, but not limited to, Shh, Dlx2, and Slit1, in response to the changed Cu level in neurospheres. Further immunohistochemical data indicated that Cu chelation also altered the expression of high-affinity copper uptake protein 1 (CTR1) and metallothionein-3 (MT3) in the SVZ as well as CTR1 in the choroid plexus, a tissue regulating brain Cu homeostasis. Taken together, this study provides first-hand evidence that a high Cu level in SVZ appears likely to maintain the stability of adult neurogenesis in this neurogenic zone.

D-Penicillamine Reveals the Amelioration of Seizure-Induced Neuronal Injury via Inhibiting Aqp11-Dependent Ferroptosis

Repetitive seizures, a common phenomenon in diverse neurologic conditions such as epilepsy, can undoubtedly cause neuronal injury and our prior work reveals that ferroptosis is a contributing factor of neuronal damage post seizure. However, there is no drug available in clinical practice for ameliorating seizure-induced neuronal impairment via targeting ferroptosis. Our present work aimed to explore whether D-penicillamine (DPA), an originally approved drug for treating Wilson’s disease, inhibited neuronal ferroptosis and alleviated seizure-associated brain damage. Our findings revealed that DPA remarkably improved neuronal survival in kainic acid (KA)-treated mouse model. Furthermore, ferroptosis-associated indices including acyl-coA synthetase long chain family member 4 (ACSL4), prostaglandin-endoperoxide synthase 2 (Ptgs2) gene and lipid peroxide (LPO) level were significantly decreased in KA mouse model after DPA treatment. In a ferroptotic cell death model induced by glutamate or erastin, DPA was also validated to evidently suppress neuronal ferroptosis. The results from RNA-seq analysis indicated that Aqp11, a gene coding previously reported channel protein responsible for transporting water and small solutes, was identified as a molecular target by which DPA exerted anti-ferroptotic potential in neurons. The experimental results from in vivo Aqp11 siRNA transfer into the brain also confirmed that knockdown of Aqp11 abrogated the inhibitory effect of seizure-induced ferroptosis after DPA treatment, suggesting that the effects of DPA on ferroptosis process are dependent upon Aqp11. In conclusion, DPA can be repurposed to cure seizure disorders such as epilepsy.

Practical insights into chronic management of hepatic Wilson’s disease

Wilson’s disease (WD) is a rare inherited disorder of human copper metabolism, with an estimated prevalence of 1:30000-1:50000 and a broad spectrum of hepatic and neuropsychiatric manifestations. In healthy individuals, the bile is the main route of elimination of copper. In WD patients, copper accumulates in the liver, it is released into the bloodstream, and is excreted in urine. Copper can also be accumulated in the brain, kidneys, heart, and osseous matter and causes damage due to direct toxicity or oxidative stress. Hepatic WD is commonly but not exclusively diagnosed in childhood or young adulthood. Adherent, non-cirrhotic WD patients seem to have a normal life expectancy. Nevertheless, chronic management of patients with Wilson’s disease is challenging, as available biochemical tests have many limitations and do not allow a clear identification of non-compliance, overtreatment, or treatment goals. To provide optimal care, clinicians should have a complete understanding of these limitations and counterbalance them with a thorough clinical assessment. The aim of this review is to provide clinicians with practical tools and suggestions which may answer doubts that can arise during chronic management of patients with hepatic WD. In particular, it summarises current knowledge on Wilson’s disease clinical and biochemical monitoring and treatment. It also analyses available evidence on pregnancy and the role of low-copper diet in WD. Future research should focus on trying to provide new copper metabolism tests which could help to guide treatment adjustments.

Wilson's Disease Update: An Indian Perspective

Wilson's disease (WD) is an autosomal recessive disorder due to ATP7B gene mutation, resulting in defective copper metabolism, with the liver and brain being primarily affected. WD being a treatable disorder, early diagnosis and proper management may result in near complete recovery. It has received significant attention over the past 50 years, with several Indian contributions. This study collates published Indian studies on WD in Pubmed and Embase databases and puts them in perspective. Several Indian case series suggest WD may be more prevalent than thought. Commonly detected ATP7B mutation in India is p.C271X. Although initial Indian series reported significant osseomuscular presentation, neuropsychiatric and hepatic manifestations dominated the later reports. A significant male predominance is observed in the Indian series. Pure hepatic presentation starts earlier than neurological or osseomuscular WD. A positive family history may be seen in nearly 50% of Indian WD cases, with a high rate of consanguinity. Up to two-third of the Indian cases may be initially misdiagnosed, with a mean diagnostic delay of up to 2 years. Abnormalities in serum ceruloplasmin and 24-hour urinary copper has been reported in more than four-fifth cases. Brain MRI is abnormal in nearly all neurological WD cases. Copper chelation remains the mainstay of therapy, with D-penicillamine being the most widely used chelator in India. Global Assessment Scale for WD is a comprehensive tool for clinical monitoring. Hepatic presentation carries a five-time higher mortality risk than neurological, with up to 90% Indian neurological WD cases recovering back to pre-morbid functionality with adequate therapy.

Management of Children and Adolescents with Wilson Disease and Neurological Worsening Following D-Penicillamine Therapy: A Single Centre Experience

Background

Most centers in developing countries prefer chelation therapy with D-penicillamine for the management of Wilson's disease (WD) because of its easy availability and affordability. Neurological worsening following treatment with D-penicillamine is not uncommon. However, there is a paucity of Indian data on the incidence of neurological worsening in children and adolescents with WD following chelation therapy. Our study objectives were to identify the prevalence of neurological worsening in children and adolescents with WD following chelation with D-penicillamine therapy and to describe the management options and outcomes in these patients.

Materials and Methods

In this retrospective chart review, children and adolescents with an established diagnosis of WD from 2010 to 2020 were identified from the hospital electronic database. Among these patients, data of children and adolescents with neurological worsening following D-penicillamine therapy were extracted and analyzed.

Results

Neurological worsening was observed in 27/122 (22.1%) children and adolescents with WD on chelation therapy with D-penicillamine. Fifteen patients with neurological worsening following D-penicillamine therapy were managed with zinc monotherapy. Four patients were managed with a combination therapy of zinc and trientine. Five patients were treated with trientine monotherapy. Re-challenging with D-penicillamine at a lower dose followed by a slow dose escalation was attempted in three patients. Gradual clinical and functional status improvement was observed in 24 cases while one patient succumbed to pneumonia.

Conclusion

Children and adolescents with WD who had neurological worsening on D-penicillamine therapy may be managed with trientine. Zinc monotherapy with copper restricted diet was also found to be effective in non-affordable patients.

Analyzing the Therapeutic Efficacy of Bis-Choline-Tetrathiomolybdate in the Atp7b-/- Copper Overload Mouse Model

Bis-choline-tetrathiomolybdate, introduced as WTX101 (now known as ALXN1840), is a first-in-class copper-protein-binding agent for oral therapy of Wilson’s disease. In contrast to other decoppering agents such as trientine or D-penicillamine it acts by forming a tripartite complex with copper and albumin, thereby detoxifying excess liver and blood copper through biliary excretion. Preclinical animal experimentation with this drug was typically done with the alternative ammonium salt of tetrathiomolybdate, which is expected to have identical properties in terms of copper binding. Here, we comparatively analyzed the therapeutic efficacy of ALXN1840, D-penicillamine and trientine in lowering hepatic copper content in Atp7b^−/− mouse. Liver specimens were subjected to laser ablation inductively conductively plasma mass spectrometry and electron microscopic analysis. We found that ALXN1840 caused a massive increase of hepatic copper and molybdenum during early stages of therapy. Prolonged treatment with ALXN1840 reduced hepatic copper to an extent that was similar to that observed after administration of D-penicillamine and trientine. Electron microscopic analysis showed a significant increase of lysosomal electron-dense particles in the liver confirming the proposed excretory pathway of ALXN1840. Ultrastructural analysis of mice treated with dosages comparable to the bis-choline-tetrathiomolybdate dosage used in an ongoing phase III trial in Wilson’s disease patients, as well as D-penicillamine and trientine, did not show relevant mitochondrial damage. In contrast, a high dose of ALXN1840 applied for four weeks triggered dramatic structural changes in mitochondria, which were notably characterized by the formation of holes with variable sizes. Although these experimental results may not be applicable to patients with Wilson’s disease, the data suggests that ALXN1840 should be administered at low concentrations to prevent mitochondrial dysfunction and overload of hepatic excretory pathways.

d-penicillamine plus garlic in the treatment of lead poisoning: a retrospective cross-sectional study

PURPOSE

Lead Poisoning is a major health problem in Iran. We aimed to compare efficacy of a standard regimen (Succimer) with that of a low-priced combination of D-penicillamine and Garlic in outpatients with lead poisoning.

METHODS

In this retrospective cross-sectional study, year-long clinical files of outpatients with lead poisoning in two referral toxicology clinics in Mashhad, Iran were reviewed. A total of 79 patients (all men), received either Succimer or a combination of D-penicillamen plus garlic (DPN + Gar), for 19 and 30 days, respectively. Clinical and laboratory data, including blood lead level (BLL), were analyzed and treatment expanses were compared between the two regimens.

RESULTS

Of 79 male patients, 42 were treated by DPN + Gar and 37 received Succimer. Mean BLL of DPN + Gar group before treatment (965.73 ± 62.54 µg/L) was higher than that of the Succimer group (827.59 ± 24.41) (p < 0.001). After treatment, BLL in both groups significantly reduced to 365.52 ± 27.61 µg/L and 337.44 ± 26.34 µg/L, respectively (p < 0.001). The price of a 19-day treatment with Succimer was approximately 28.6 times higher than a one-month course of treatment with garlic plus DPN. None of the treatments caused serious side effects in the patients.

CONCLUSION

Combination therapy with DPN + Gar is as effective as Succimer in Pb poisoning, while treatment with Succimer is significantly more expensive.

Zinc monotherapy for young patients with oligosymptomatic Wilson disease: A single center, retrospective study

BACKGROUND AND AIMS

Few studies have focused on the treatment failure of zinc monotherapy for oligosymptomatic Wilson disease (WD) patients. Therefore, we aimed to evaluate the long-term efficacy of zinc monotherapy in oligosymptomatic patients and to analyze the possible factors that may influence the outcome of this treatment.

METHODS

We retrospectively reviewed the medical records of oligosymptomatic WD patients who received zinc monotherapy from the time of diagnosis. Then, the characteristics of patients who were treated with zinc monotherapy successfully and those who experienced treatment failure were investigated.

RESULTS

Forty oligosymptomatic WD patients were identified that have received zinc monotherapy as initial treatment, with a median age of 3.83 years at the time of diagnosis. 36 (90%) patients had abnormal alanine transaminase/aspartate transaminase levels at baseline. None of the patients became symptomatic during zinc monotherapy. 28 (70%, Group 1) patients were treated with zinc monotherapy successfully for a median period of 2.4 years. In Group 1, serum aminotransferase levels significantly decreased 6 and 12 months after zinc therapy compared to the baseline levels (P <  0.05). 12 (30%, Group 2) patients experienced treatment failure with zinc monotherapy due to uncontrolled serum liver enzyme levels, and d-penicillamine was combined. The baseline 24-hour urine copper levels before treatment were significantly higher in Group 2 compared to that in Group 1 (182.5 vs 90.92 μg /day, P = 0.018). Comparing the age at onset; ceruloplasmin, serum copper, ALT, and AST levels; and proportions of abdominal ultrasonography abnormality at baseline between Group 1 and 2 revealed no statistically significant differences.

CONCLUSIONS

We found that high initial 24 -h urinary copper levels may lead to treatment failure of zinc monotherapy in oligosymptomatic WD patients. It might be reasonable to follow up liver function tests more closely during zinc monotherapy and to begin combination treatment with chelators early in patients with high level of 24 -h urinary copper.

Adherence to treatment, a challenge even in treatable metabolic rare diseases: A cross sectional study of Wilson's disease

Wilson's disease (WD), a rare genetic disorder responsible for copper accumulation in the body, is fatal if left untreated. Although there are effective treatments, adherence to treatment tends to be low. We evaluated the medication adherence of 139 patients using the Morisky scale. Adherence was correlated with age at diagnosis and at inclusion in the study, the form of the disease, the treatment, the duration of treatment, delivery and storage problems, depression, anxiety, the level of education, and the biological data. 32.4% of the patients had low adherence; their levels of exchangeable copper were significantly higher than those of the patients with high or medium adherence (P = .049). The average age of the patients at the time of the study was significantly higher in those with high adherence than in those with medium or low adherence (P = .043). 75.9% of the patients with high adherence had a neurological form and 26.7% of the patients with low adherence were asymptomatic (P = .0090). The duration of treatment was significantly longer in the patients with high adherence than in those with medium or low adherence (P = .0192). The type of treatment (chelators or zinc) had no impact on the level of adherence. Forty-four percent of the patients experienced problems dispensing and storing medications. Despite the availability of effective treatments for this rare disease, adherence problems occur with Wilson's disease in particular in asymptomatic patients. Although different factors are involved, sustained multidisciplinary management on a case-by-case basis is necessary.

Safety profile of D-penicillamine: a comprehensive pharmacovigilance analysis by FDA adverse event reporting system

BACKGROUND

D-penicillamine (D-pen) is a copper-chelating drug and has immune-modulatory properties. D-pen is used to treat rheumatoid arthritis, Wilson's disease, and kidney stones (cystinuria). However, associated adverse events (AEs) of D-pen treatment are frequent and often serious. Therefore, a comprehensive assessment of the safety profile of D-pen is urgently needed.

RESEARCH DESIGN AND METHODS

We identified and analyzed AEs associated with D-pen between April-1970 to July-2020 from the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) databases and calculated the reported odds ratio (ROR) with 95% confidence intervals (CI) using the disproportionality analysis.

RESULTS

A total of 9,150,234 AEs related to drugs were reported in the FAERS database, of which 542 were related to D-Pen. We report that D-pen was associated with dystonia (ROR: 20.52; 95%CI: 12.46-33.80), drug hypersensitivity (ROR: 5.42; 95%CI: 3.72-7.90), pancytopenia (ROR: 10.20; 95%CI: 5.61-18.56), joint swelling (ROR: 9.07; 95%CI: 5.51-14.94), renal-impairment (ROR: 6.68; 95%CI: 3.67-12.15), dysphagia (ROR: 5.05; 95%CI: 2.76-8.89), aggravation of condition (ROR: 4.16; 95%CI: 2.60-6.67), congestive cardiac failure (ROR: 4.04; 95%CI: 2.22-7.35), peripheral edema (ROR: 3.77; 95%CI: 2.17-6.55), tremor (ROR: 3.46; 95%CI: 2.00-6.01), pyrexia (ROR: 3.46; 95%CI: 2.00-6.01), and gait disturbance (ROR: 2.41; 95%CI: 1.29-4.52).

CONCLUSIONS

Patients taking D-pen require close monitoring of renal function, blood counts, immunity, liver, cardiac function, and neurological function. D-pen suppresses immune system which maximizes the risk of infection.

D-Penicillamine: The State of the Art in Humans and in Dogs from a Pharmacological and Regulatory Perspective

Chelant agents are the mainstay of treatment in copper-associated hepatitis in humans, where D-penicillamine is the chelant agent of first choice. In veterinary medicine, the use of D-penicillamine has increased with the recent recognition of copper-associated hepatopathies that occur in several breeds of dogs. Although the different regulatory authorities in the world (United States Food and Drugs Administration-U.S. FDA, European Medicines Agency-EMEA, etc.) do not approve D-penicillamine for use in dogs, it has been used to treat copper-associated hepatitis in dogs since the 1970s, and is prescribed legally by veterinarians as an extra-label drug to treat this disease and alleviate suffering. The present study aims to: (a) address the pharmacological features; (b) outline the clinical scenario underlying the increased interest in D-penicillamine by overviewing the evolution of its main therapeutic goals in humans and dogs; and finally, (c) provide a discussion on its use and prescription in veterinary medicine from a regulatory perspective.

Pediatric Wilson disease presenting as acute liver failure: Prognostic indices

BACKGROUND

Acute liver failure (ALF) can be a primary presentation of Wilson disease (WD). Mortality rates are high in WD with ALF (WDALF). Predictions of mortality in WDALF vary by model and are sometimes contradictory, perhaps because few patients are studied or WD diagnoses are questionable.

AIM

To determine the outcomes among well-documented WDALF patients and assess mortality model performance in this cohort.

METHODS

We reviewed the medical records of our pediatric WDALF patients (n = 41 over 6-years-old, single-center retrospective study) and compared seven prognostic models (King’s College Hospital Criteria, model for end-stage liver disease/pediatric end-stage liver disease scoring systems, Liver Injury Unit [LIU] using prothrombin time [PT] or international normalized ratio [INR], admission LIU using PT or INR, and Devarbhavi model) with one another.

RESULTS

Among the 41 Han Chinese patients with ALF, WD was established by demonstrating ATP7B variants in 36. In 5 others, Kayser-Fleischer rings and Coombs-negative hemolytic anemia permitted diagnosis. Three died during hospitalization and three underwent liver transplantation (LT) within 1 mo of presentation and survived (7.3% each); 35 (85.4%) survived without LT when given enteral D-penicillamine and zinc-salt therapy with or without urgent plasmapheresis. Parameters significantly correlated with mortality included encephalopathy, coagulopathy, and gamma-glutamyl transpeptidase activity, bilirubin, ammonia, and serum sodium levels. Area under the receiver operating curves varied among seven prognostic models from 0.981 to 0.748 with positive predictive values from 0.214 to 0.429.

CONCLUSION

WDALF children can survive and recover without LT when given D-penicillamine and Zn with or without plasmapheresis, even after enlisting for LT.

Nasal Delivery of D-Penicillamine Hydrogel Upregulates a Disintegrin and Metalloprotease 10 Expression via Melatonin Receptor 1 in Alzheimer's Disease Models

Alzheimer's disease (AD) is a type of neurodegenerative disease that is associated with the accumulation of amyloid plaques. Increasing non-amyloidogenic processing and/or manipulating amyloid precursor protein signaling could reduce AD amyloid pathology and cognitive impairment. D-penicillamine (D-Pen) is a water-soluble metal chelator and can reduce the aggregation of amyloid-β (Aβ) with metals in vitro. However, the potential mechanism of D-Pen for treating neurodegenerative disorders remains unexplored. In here, a novel type of chitosan-based hydrogel to carry D-Pen was designed and the D-Pen-CS/β-glycerophosphate hydrogel were characterized by scanning electron microscopy and HPLC. Behavior tests investigated the learning and memory levels of APP/PS1 mice treated through the D-Pen hydrogel nasal delivery. In vivo and in vitro findings showed that nasal delivery of D-Pen-CS/β-GP hydrogel had properly chelated metal ions that reduced Aβ deposition. Furthermore, D-Pen mainly regulated A disintegrin and metalloprotease 10 (ADAM10) expression via melatonin receptor 1 (MTNR1α) and the downstream PKA/ERK/CREB pathway. The present data demonstrated D-Pen significantly improved the cognitive ability of APP/PS1 mice and reduced Aβ generation through activating ADAM10 and accelerating non-amyloidogenic processing. Hence, these findings indicate the potential of D-Pen as a promising agent for treating AD.

Recent advances in Wilson disease

Wilson disease (WD) is rare genetic disorder that presents with varied phenotype that can at times make the diagnosis challenging. Medical treatments are available, but there are still unmet needs for patients. Since life-long therapy is necessary, adherence to medical therapy and best practices for monitoring and individualizing therapy continue to evolve. Studies are ongoing that address some of these issues. In the current review we focused our attention to recent advances in the diagnosis of WD, current medical treatments, future potential therapies and treatment monitoring. We include discussion of new methodology for detection and quantitation of ophthalmologic signs of WD, new brain imaging modalities for early detection of neurologic involvement in patients and potential new diagnostic methodology using blood samples that may be applicable to newborn screening and adult disease diagnosis. In addition, there are new strategies aimed at improving adherence and outcomes with currently available therapies, including once daily chelation dosing and discussion of the efficacy of different zinc salt compounds. With respect to new therapies with different mechanisms of action, we discuss studies on Bis-choline tetrathiomolybdate (TTM) in patients, pre-clinical studies of a novel chelator methanobactin and other animal studies exploring cures for WD with gene therapy using adeno-associated vectors (AAVs) that introduce ATP7B into liver cells. There are also promising advances in the more accurate measurement of non-ceruloplasmin bound copper and exchangeable copper in the circulation which would potentially help with monitoring and individualization of treatment and possibly play a role in future disease diagnosis.

Combined dimercaptosuccinic acid and zinc treatment in neurological Wilson's disease patients with penicillamine-induced allergy or early neurological deterioration

The clinical data of safety and efficacy of a combined treatment with dimercaptosuccinic acid (DMSA) and Zinc with 2 years’ follow-up in 60 neurological Wilson’s disease (WD) patients was retrospectively analyzed. All the patients included in the present study were newly diagnosed and initialized with D-penicillamine (DPA) treatment but were found to have either neurological deterioration or allergy, and their treatment was switched to a combined treatment of DMSA and Zinc. Fifty-one patients (85%) had the neurological symptoms improved 1 and 2 years after treatment, 7 (11.67%) experienced a stable neurological condition, and 2 (3.33%) suffered deterioration of neurological symptoms. No early neurological deterioration was observed in all patients. Twenty-five percent patients experienced mild adverse reactions which did not require a discontinuation of the DMSA and Zinc treatment. Our study confirmed the safety and efficacy of the combined DMSA and Zinc therapy as an initial and probably long-term treatment in neurological WD patients.

pH-modulated aggregation-induced emission of Au/Cu nanoclusters and its application to the determination of urea and dissolved ammonia

A fluorescence platform is designed based on aggregation-induced emission of Au/Cu nanoclusters (Au/Cu NCs) driven by pH value. When pH increases from 6.0 to 7.0, Au/Cu NCs change from aggregation to dispersion, accompanied by the oxidation of Cu cores. Under the catalysis of urease, urea is hydrolysed to release ammonia, which further undergoes a hydrolysis reaction to produce OH^-, causing the pH to increase. The fluorescence of Au/Cu NCs quenches linearly at 590 nm with the excitation wavelength at 320 nm when the concentration of urea varies from 5.0 to 100 μM. The limit of detection (LOD) and limit of quantification (LOQ) of urea are 2.23 and 7.45 μM, respectively. Combined with headspace single-drop microextraction technology, Au/Cu NCs are employed to monitor dissolved ammonia with low-cost and simple operation. The linear range of dissolved ammonia is from 20 to 300 μM. The LOD and LOQ of dissolved ammonia are 7.04 and 23.4 μM, respectively. The relative standard deviation (RSD) values of the intra-day and inter-day precision of urea are 2.4-3.0% and 3.0-3.7%, respectively, and those of dissolved ammonia are in the range 3.4-5.1% (intra-day precision) and 4.2-5.8% (inter-day precision). No interferences have been indentified in the determination of urea and dissolved ammonia. Finally, the proposed method has been applied to determine urea in human urine samples and dissolved ammonia in water samples with satisfactory results.Graphical abstract The pH increase produces the dispersion and decomposition of Au/Cu NCs, leading to the fluorescence quenching. Both urea and dissolved ammonia are detected successfully because they cause the pH change to alkaline.

Observation on the changes of clinical symptoms, blood and brain copper deposition in Wilson disease patients treated with dimercaptosuccinic acid for 2 years

OBJECTIVE

To compare the clinical symptoms, brain copper deposition changes of Meso-2,3-dimercaptosuccinic acid (DMSA) and penicillamine therapy in patients with Wilson disease (WD) within 2 years.

METHODS

68 drug-naive patients with WD were enrolled. 10 WD patients treated with zinc gluconate alone were used as the control group. Neurological symptoms were scored using the modified Young Scale. Liver function tests, copper indices and sensitive weighted imaging (SWI) examination were collected. The values of corrected phase (CP) were collected. WD patients were treated with DPA (group 1) or DMSA (group 2) for two years, and followed up every 2 months.

RESULTS

The ratio of neurological improvement in group 2 was higher than that in group 1 (P = 0.029). Higher rate of neurologic worsening was noticed in patients treated with DPA vs DMSA (P = 0.039). The post-treatment neurological score of DMSA group was lower than that of Zn group (P = 0.037). Hepatic function in 63.3% of patients was stable, while 16.7% was improved, and 20% was deteriorated, after DMSA therapy. Urinary copper levels were lower 1 month (p = 0.032), 4 months (p = 0.041), 12 months (p = 0.037) after initiation of treatment in group 2 than in group 1. At the first year of treatment, the CP values in globus pallidus and substantia nigra in group 2 were higher than those in group 1 (P = 0.034,0.039). At the second year of treatment, the CP values of substantia nigra in group 2 were higher (P = 0.041). Discontinuation was more common in patients on DPA therapy (P = 0 0.032).

CONCLUSIONS

DMSA could remove metal from brain tissue faster than DPA. DMSA is effective for neurologic symptoms, while the outcome for hepatic symptoms is not entirely satisfactory. DMSA therapy is better tolerated than DPA.

Effect of chelation therapy in pediatric Wilson's disease: Liver and endoscopic outcome

BACKGROUND

As there is paucity of exclusive literature on pediatric hepatic Wilson's disease (WD), this study was undertaken to evaluate the efficacy of chelation on hepatocellular function and portal hypertension in WD.

METHODS

Wilson's disease patients with ≥9 months of follow-up were evaluated for response to chelation therapy in the following categories: (a) complete remission, (b) partial remission (c) progression of disease; (d) drug toxicity. Pediatric end-stage liver disease (PELD), Nazar and New Wilson Index scores were compared. Hemodynamically stable patients underwent esophagogastroduodenoscopy (baseline and surveillance) and received prophylaxis (primary or secondary). Endoscopic outcome was assessed at follow-up.

RESULTS

Of the 111 WD children (aged 9 [3-15] years; PELD score 16 [-11 to 60]), 65 with follow-up of 3.6 (0.8-12) years on chelation (83% D-penicillamine monotherapy, 17% D-penicillamine and zinc) were analyzed. 81% had severe disease at presentation. Favorable outcome (complete and or partial remission), progression of disease and drug toxicity were seen in 71%, 29% and 10.8%, respectively. Two-thirds had esophageal varices which did not show progression. Large esophageal varices (16%) were effectively downgraded in 3 (2-6) therapeutic endoscopic sessions. Nazar score and PELD score at baseline were independent predictors of outcome with favorable correlation with each other (r = .864, P < .001). PELD cutoff 9.45 (AUC: 71%, sensitivity: 87%, specificity: 50%; P = .009) and Nazar score cut off 3.5 (AUC: 68%, sensitivity: 83%, specificity: 50%; P = .02) were associated with poor prognosis.

CONCLUSIONS

Despite severe liver disease, the majority of hepatic WD can be managed on D-penicillamine monotherapy. PELD score and Nazar score effectively determine the outcome.

Update on cystine stones: current and future concepts in treatment

Cystine stones are relatively uncommon compared with other stone compositions, constituting just 1% to 2% of adult urinary tract stone diseases, and accounting for up to 10% of pediatric stone diseases. Two responsible genes of cystinuria have been identified, the SLC3A1 and the SLC7A9. Cystinuria is diagnosed by family history, stone analysis, or by measurement of urine cystine excretion. Current treatments for cystinuria include increased fluid intake to increase cystine solubility by maintaining daily urine volume of greater than 3 Liter (L). Limiting sodium and protein intake can decrease cystine excretion. When conservative therapy fails, then pharmacologic therapy may be effective. Alkaline urine pH in the 7.0-7.5 range will reduce cystine solubility and can be achieved by the addition of alkali therapy. If these measures fail, cystine-binding thiol drugs such as tiopronin and D-penicillamine are considered. These compounds bind cysteine and prevent the formation of less soluble cystine. These drugs, however, have poor patient compliance due to adverse effects. Captopril can be useful in the treatment of cystine stones but the drug has not been tested in rigorous clinical trials. Novel potential therapies such as alpha-lipoic acid and crystal growth inhibitors (L-cystine dimethyl ester (L-CDME) and L-cystine methyl ester (L-CME)) were developed and tested in animals. Those therapies showed promising results. Compliance with treatment was associated with a lower rate of cystine stone formation.

A graphene quantum dots-Pb2+ based fluorescent switch for selective and sensitive determination of D-penicillamine

Taking consideration of metal-induced fluorescence quenching and excellent coordination effect of D-penicillamine (D-PA), a graphene quantum dots (GQDs)-based fluorescent switch for D-PA detection was designed and established firstly with the help of lead ions. GQDs obtained from citric acids made them rich in carboxyl and hydroxyl groups, giving GQDs the ability to combine with lead ions. As anticipated, the fluorescence intensity was quenched by Pb²⁺ through electron transfer process. Further, the addition of D-PA effectively recovered the fluorescence due to the departure of Pb²⁺ from GQDs aroused by the strong coordination between D-PA and Pb²⁺. Thus, a fluorescent switch was activated for D-PA detection. The fluorescence recovery efficiencies were found to be proportional to the concentration of D-PA in the range of 0.6-50 μmol L^-1 and the detection limit was 0.47 μmol L^-1. The real sample detection was performed in human urea sample and satisfactory recoveries of 96.84%-102.13% were obtained. The GQDs-Pb²⁺ based fluorescent switch sensing method was firstly established with low detection limit and wide linear range, making it a supplement and improvement for D-PA detection.

The Synergistic Antifungal Effect and Potential Mechanism of D-Penicillamine Combined With Fluconazole Against Candida albicans

Over the last few decades, candidiasis has exhibited an increasing incidence worldwide, causing high mortality in immunocompromised patients. Candida albicans is one of the leading opportunistic fungal pathogens. However, due to the increased use of antifungal agents, resistance of C. albicans to conventional agents, especially fluconazole, has frequently emerged. Therefore, research on the use of combinations of current drugs to sensitize antifungal agents and overcome fungal resistance has attracted considerable attention. This study demonstrated for the first time that D-penicillamine (PCA) combined with fluconazole showed a synergistic effect against C. albicans. PCA combined with fluconazole not only showed synergistic effects against planktonic cells of C. albicans, but also showed synergistic effects against C. albicans biofilms formed within 12 h in vitro. In addition, a Galleria mellonella infection model was used to evaluate the in vivo effects of this drug combination. The results showed that the combination of the two drugs could improve the survival rate, decrease the fungal burden, and reduce the tissue invasion of G. mellonella larvae. Finally, we explored the potential synergistic mechanisms of the drug combination, mainly including inhibition of the morphological transformation, reduction of the intracellular calcium concentration, and the activation of metacaspase, which is closely related to cell apoptosis. These findings might provide novel insights into antifungal drug discovery and the treatment of candidiasis caused by C. albicans.

Pompholyx-Like Eruptions Induced by Penicillamine in a Patient with Wilson's Disease

Wilson's disease is an inherited disorder of copper metabolism that results in excessive accumulation of copper in various organs, with liver being the primary site of involvement. D-penicillamine (DPA) as a chelating agent forms the mainstay of therapy; however, it can cause a myriad of adverse effects on long-term use. The major adverse effects reported with DPA include disorders of collagen synthesis, such as pseudoxanthoma elasticum-like lesions, autoimmune blistering diseases, and urticarial lesions. Here, we report a young girl who developed extensive pompholyx-like blisters within a few months of starting DPA which on histopathology showed a spongiotic reaction. The lesions improved on stopping DPA and initiation of oral steroids.

Treatment of adult lead poisoning with D-penicillamine

Background The aim of the current study was to evaluate the efficacy of D-penicillamine in the treatment of lead poisoning mainly in the outpatient setting. Methods In a case series study performed during the recent epidemic of lead poisoning in Iran, lead-poisoned patients referring to our outpatient clinic were treated with 250-mg D-penicillamine capsules administered every 6 h for 5 or 10 days based on availability of the medication. They were recommended to re-check blood lead level (BLL) 4 weeks after cessation of the treatment and refer to our clinic again. Results In 63 patients with lead poisoning but without signs and symptoms of lead encephalopathy, median BLL was 106 [84, 131] μg/dL on presentation, which declined to a mean of 52.6 ± 28.8 μg/dL after a median treatment period of 7 [5, 10] days (p < 0.001). There was no statistically significant difference between the 5- and 10-day treatment protocols regarding complications and recovery. Treatment had resulted in a median decrease of 54 μg/dL [33, 90] (range: -20 to 231 μg/dL) in the patients' BLLs (33.9% declined in BLL measurements; range: -29.69% to 99.06%). Conclusions D-penicillamine may be an acceptable substitute treatment in adult lead poisoning. Although our sample size was limited, we could not detect any serious adverse effects in our cases showing that D-penicillamine resulted in acceptable recovery rates. This may be helpful especially in epidemics with limitations in antidote access.

Clinical management of Wilson disease

The availability of effective therapies distinguishes Wilson disease (WD) from other inherited neurometabolic diseases. The cause of hepatic, neurologic or psychiatric symptoms is copper overload and subsequent copper toxicity. Diagnosed WD patients require life-long pharmacologic therapy that is focused on reversal of copper overload with maintenance of a long-term negative copper balance. This is associated with the rapid control of free or non-ceruloplasmin bound copper that is mostly responsible for acute cytotoxic effects. Currently available therapies can be divided into chelators and zinc salts. They have different mechanisms of action and the onset of efficacy that influences their selection in acute and chronic stages of therapy. We review the use of D-penicillamine and trientine for chelation therapies, including the required monitoring of therapy for its efficacy and possible overtreatment with iatrogenic copper deficiency. Additionally, the use of zinc salts is also discussed, including a possibility of its use for the initial therapy in an acute stage of the disease. Supportive and symptomatic therapies for liver failure and neuropsychiatric symptoms are also reviewed.

Adverse events associated with currently used medical treatments for cystinuria and treatment goals: results from a series of 442 patients in France

OBJECTIVE

To evaluate medical treatments, in terms of adverse events (AEs) and therapeutic goals, in a large series of patients with cystinuria.

PATIENTS AND METHODS

Data from 442 patients with cystinuria were recorded retrospectively. Crystalluria was studied in 89 patients. A mixed-effects logistic regression model was used to estimate how urine pH, specific gravity and cysteine-binding thiols (CBT) correlate with risk of cystine crystalluria.

RESULTS

Alkalizing agents and CBT agents were given to 88.8% (n = 381) and 55.3% (n = 238) of patients, respectively. Gastrointestinal AEs were reported in 12.3%, 10.4% and 2.6% of patients treated with potassium bicarbonate, potassium citrate and sodium bicarbonate, respectively (P = 0.008). The percentages of patients who experienced at least one AE with tiopronin (24.6%) and with D-penicillamine (29.5%) were similar (P = 0.45). Increasing urine pH and decreasing urine specific gravity significantly reduced the risk of cystine crystalluria, whereas D-penicillamine and tiopronin treatments did not reduce this risk (odds ratio [OR] 1 for pH ≤6.5; OR 0.52 [95% confidence interval {95% CI} 0.28-0.95] for 7.0 <pH ≤7.5, P = 0.03; OR 0.26 [95% CI 0.13-0.53] for 7.5 < pH ≤8.0, P <0.001; OR 1 for specific gravity ≤1.005 OR 5.76 [95% CI 1.45-22.85] for 1.006 ≤ specific gravity ≤1.010, P = 0.01; and OR 11.06 [95% CI 2.76-44.26] for 1.011 ≤ specific gravity ≤ 1.014, P < 0.001). Increased urine pH significantly increased the risk of calcium phosphate crystalluria (OR 1 for pH≤ 6.5; OR 6.09 [95% CI 2.15-17.25] for pH >8.0, P <0.001).

CONCLUSION

Adverse events were frequent with D-penicillamine and tiopronin. Alkaline hyperdiuresis was well tolerated and reduced cystine crystalluria. Urine specific gravity ≤1.005 and urine pH >7.5, while warning about calcium-phosphate crystallization, should be the goals of medical therapy.

Update on the Diagnosis and Management of Wilson Disease

PURPOSE OF REVIEW

Exciting developments relating to Wilson disease (WD) have taken place with respect to both basic biological and clinical research. This review critically examines some of these findings and considers their implications for current thinking about WD. It is not a comprehensive review of WD as a clinical disorder.

RECENT FINDINGS

The structure of the gene product of ATP7B, abnormal in WD, is being worked out in detail, along with a broader description of how the protein ATP7B (Wilson ATPase) functions in cells including enterocytes, not only in relation to copper disposition but also to lipid synthesis. Recent population studies raise the possibility that WD displays incomplete penetrance. Innovative screening techniques may increase ascertainment. New strategies for diagnosing and treating WD are being developed. Several disorders have been identified which might qualify as WD-mimics. WD can be difficult to diagnose and treat. Insights from its pathobiology are providing new options for managing WD.

Elastosis perforans serpiginosa: causes and associated disorders

BACKGROUND

Elastosis perforans serpiginosa (EPS) is an uncommon cutaneous disorder classified under perforating diseases (PD); a group of dermatoses with transepidermal extrusion of collagen or elastic tissue. Three EPS subtypes have been reported that differ according to aetiology, associated diseases, and histopathological features. Herein, we report a systematic review of the literature, as well as a case of a 41-year-old woman with Wilson disease treated with penicillamine (PCM), who developed EPS after 11 years of drug intake.

OBJECTIVES

To analyse and characterise EPS subtypes based on an evaluation of potential different histological patterns.

MATERIALS & METHODS

A systematic literature search in Pubmed was performed to identify articles describing EPS.

RESULTS

A peculiar histological pattern was identified in EPS PCM-related patients, either in affected or unaffected skin samples. Using specific elastic fibre stains (Verhoeff-van Gieson, Weigert, and Orcein), fibres appeared with an irregular surface with thorn-like protrusion, probably due to weaker fibre cross-links, making them unable to re-expand after contraction along their long axis. Interestingly, similar histological patterns have also been reported in elastic tissues of vessel walls of the lungs and upper respiratory tract, joints, visceral adventitia, and kidney.

CONCLUSIONS

A distinctive histological pattern of PCM-related EPS is observed in affected and normal-appearing skin, as well as extracutaneous elastic tissue, suggesting serious potential widespread drug-induced systemic elastolytic damage.

Characteristics and prevalence of Wilson's disease: A 2013 observational population-based study in France

BACKGROUND AND AIMS

Only a few epidemiological studies on the incidence and prevalence of Wilson's disease (WD) have been performed to date, and the results vary widely according to the reports. The aim of the study was to investigate the prevalence, ambulatory care and treatments of patients with WD in France.

METHODS

Among the 58 million general health scheme beneficiaries (86% of the French population), people managed for WD in 2013 were identified using hospitalisation diagnosis in 2011-2013 or specific long-term disease status with a 100% reimbursement for specific healthcare in 2013. Data were derived from the Sniiram (National Health Insurance Information System database). Prevalence by age and sex were calculated.

RESULTS

In 2013, 906 prevalent cases were identified, yielding a crude prevalence of 1.5 cases per 100,000; 1.65 per 100,000 in males and 1.44 per 100,000 in females. This prevalence is comparable to that reported in other population-based studies in European countries and to a study using a similar method. Almost 40% of patients were treated by D-penicillamine and 14.3% were treated by zinc acetate. Trientine, delivered on a compassionate basis, was not available in the reimbursement database. In 2013, 1.3% of patients underwent liver transplantation and 4% had already undergone liver transplantation in previous years. Fifteen per cent of patients received antidepressants, a higher rate than in general population.

CONCLUSIONS

This is the first French population-based epidemiological study of WD in a comprehensive population based on administrative data and constitutes an important step to understand the impact of WD and to study quality of care.

D-penicillamine combined with inhibitors of hydroperoxide metabolism enhances lung and breast cancer cell responses to radiation and carboplatin via H2O2-mediated oxidative stress

D-penicillamine (DPEN), a copper chelator, has been used in the treatment of Wilson's disease, cystinuria, and rheumatoid arthritis. Recent evidence suggests that DPEN in combination with biologically relevant copper (Cu) concentrations generates H₂O₂ in cancer cell cultures, but the effects of this on cancer cell responses to ionizing radiation and chemotherapy are unknown. Increased steady-state levels of H₂O₂ were detected in MB231 breast and H1299 lung cancer cells following treatment with DPEN (100µM) and copper sulfate (15µM). Clonogenic survival demonstrated that DPEN-induced cancer cell toxicity was dependent on Cu and was significantly enhanced by depletion of glutathione [using buthionine sulfoximine (BSO)] as well as inhibition of thioredoxin reductase [using Auranofin (Au)] prior to exposure. Treatment with catalase inhibited DPEN toxicity confirming H₂O₂ as the toxic species. Furthermore, pretreating cancer cells with iron sucrose enhanced DPEN toxicity while treating with deferoxamine, an Fe chelator that inhibits redox cycling, inhibited DPEN toxicity. Importantly, DPEN also demonstrated selective toxicity in human breast and lung cancer cells, relative to normal untransformed human lung or mammary epithelial cells and enhanced cancer cell killing when combined with ionizing radiation or carboplatin. Consistent with the selective cancer cell toxicity, normal untransformed human lung epithelial cells had significantly lower labile iron pools than lung cancer cells. These results support the hypothesis that DPEN mediates selective cancer cell killing as well as radio-chemo-sensitization by a mechanism involving metal ion catalyzed H₂O₂-mediated oxidative stress and suggest that DPEN could be repurposed as an adjuvant in conventional cancer therapy.

Pre-Clinical Studies with D-Penicillamine as a Novel Pharmacological Strategy to Treat Alcoholism: Updated Evidences

Ethanol, as other drugs of abuse, is able to activate the ventral tegmental area dopamine (VTA-DA) neurons leading to positively motivational alcohol-seeking behavior and use, and, ultimately to ethanol addiction. In the last decades, the involvement of brain-derived acetaldehyde (ACD) in the ethanol actions in the mesolimbic pathway has been widely demonstrated. Consistent published results have provided a mechanistic support to the use of ACD inactivating agents to block the motivational and reinforcing properties of ethanol. Hence, in the last years, several pre-clinical studies have been performed in order to analyze the effects of the sequestering ACD agents in the prevention of ethanol relapse-like drinking behavior as well as in chronic alcohol consumption. In this sense, one of the most explored interventions has been the administration of D-Penicillamine (DP). These pre-clinical studies, that we critically summarize in this article, are considered a critical step for the potential development of a novel pharmacotherapeutic strategy for alcohol addiction treatment that could improve the outcomes of current ones. Thus, on one hand, several experimental findings provide the rationale for using DP as a novel therapeutic intervention alone and/or in combination to prevent relapse into alcohol seeking and consumption. On the other hand, its effectiveness in reducing voluntary ethanol consumption in long-term experienced animals still remains unclear. Finally, this drug offers the additional advantage that has already been approved for use in humans, hence it could be easily implemented as a new therapeutic intervention for relapse prevention in alcoholism.

Chemosensitivity of U251 Cells to the Co-treatment of D-Penicillamine and Copper: Possible Implications on Wilson Disease Patients

D-Penicillamine (PA), a copper chelator, and one of the recommended drugs for treatment of Wilson disease (WD) has been reported to worsen the symptoms of patients with neurologic presentations. However, the cause of this paradoxical response has not been fully elucidated and requires further investigations. Accordingly, we have studied the in vitro effect of Copper (Cu) and/or PA treatment on human glioblastoma U251 cells as an in vitro model of Cu cytotoxicity. Treatment of U251 cells with either Cu or PA exerted no significant effect on their morphology, viability or ROS level. In contrast, co-treatment with Cu-PA caused a decrease in viability, altered glutathione and ceruloplasmin expression coupled with marked increase in ROS; depolarization of mitochondrial membrane potential; and an increase in Sub G0 phase; along with alpha-Fodrin proteolysis. These findings along with the absence of LDH release in these assays, suggest that combined Cu-PA exposure induced apoptosis in U251 cells. In addition, pre-/or co-treatment with antioxidants showed a protective effect, with catalase being more effective than N-acetyl cysteine or trolox in restoring viability and reducing generated ROS levels. By comparison, a similar analysis using other cell lines showed that rat PC12 cells were resistant to Cu and/or PA treatment, while the neuroblastoma cell line SH-SY5Y was sensitive to either compound alone, resulting in decreased viability and increased ROS level. Taken together, this study shows that glioblastoma U251 cells provide a model for Cu-PA cytotoxicity mediated by H₂O₂. We postulate that PA oxidation in presence of Cu yields H₂O₂ which in turn permeates the plasma membrane and induced apoptosis. However, other cell lines exhibited different responses to these treatments, potentially providing a model for cell type- specific cytotoxic responses in the nervous system. The sensitivity of different neural and glial cell types to Cu-PA treatment may therefore underlie the neurologic worsening occurring in some PA-treated WD patients. Our results also raise the possibility that the side effects of PA treatment might be reduced or prevented by administering antioxidants.

Functional analysis and drug response to zinc and D-penicillamine in stable ATP7B mutant hepatic cell lines

AIM: To study the effect of anti-copper treatment for survival of hepatic cells expressing different ATP7B mutations in cell culture.

METHODS: The most common Wilson disease (WD) mutations p.H1069Q, p.R778L and p.C271*, found in the ATP7B gene encoding a liver copper transporter, were studied. The mutations represent major genotypes of the United States and Europe, China, and India, respectively. A human hepatoma cell line previously established to carry a knockout of ATP7B was used to stably express WD mutants. mRNA and protein expression of mutant ATP7B, survival of cells, apoptosis, and protein trafficking were determined.

RESULTS: Low temperature increased ATP7B protein expression in several mutants. Intracellular ATP7B localization was significantly impaired in the mutants. Mutants were classified as high, moderate, and no survival based on their viability on exposure to toxic copper. Survival of mutant p.H1069Q and to a lesser extent p.C271* improved by D-penicillamine (DPA) treatment, while mutant p.R778L showed a pronounced response to zinc (Zn) treatment. Overall, DPA treatment resulted in higher cell survival as compared to Zn treatment; however, only combined Zn + DPA treatment fully restored cell viability.

CONCLUSION: The data indicate that the basic impact of a genotype might be characterized by analysis of mutant hepatic cell lines.

[Toxic nephropathy secondary to occupational exposure to metallic mercury]

Toxic nephrophaties secondary to occupational exposure to metals have been widely studied, including membranous nephropathy by mercury, which is rare. Occupational poisoning by mercury is frequent, neurological symptoms are the main form of clinical presentation. Secondary renal involvement in chronic exposure to metallic mercury can cause glomerular disease by deposit of immune-complexes. Membranous glomerulopathy and minimal change disease are the most frequently reported forms. Here we describe the case of a patient with occupational exposure to metallic mercury, where nephrotic syndrome due to membranous glomerulonephritis responded favorably to both chelation and immunosuppressive therapy.

Improved effect of the combination naltrexone/D-penicillamine in the prevention of alcohol relapse-like drinking in rats

Opioid antagonists are licensed drugs for treating alcohol use disorders; nonetheless, clinical studies have evidenced their limited effectiveness. Preclinical findings indicate that opioid receptor (OR) antagonists, such as naltrexone (NTX), reduce the alcohol deprivation effect (ADE). However, a detailed analysis of published data shows the existence of a delayed increase in ethanol consumption after continuous OR blockade, a phenomenon originally called as 'delayed ADE'. We have recently reported that D-penicillamine (DP) is able to prevent ADE through a mechanism dependent on the inactivation of acetaldehyde, the main metabolite of ethanol. Hypothetically, OR activation would be triggered by acetaldehyde after ethanol consumption. Hence, we conjecture that the combination of NTX and DP, due to their distinct but complementary mechanisms to impede OR activation, may be more efficacious in the prevention of the ADE and, specifically, the 'delayed ADE'. Herein, we compare the effects of the combination NTX/DP (NTX: 2×5 mg/kg SC injection daily/DP: SC infusion (0.25 mg/h)) versus NTX on the ADE in long-term ethanol-experienced rats. As expected, NTX-treated animals displayed a delayed ADE. However, NTX/DP treatment prevented this delayed effect. Our present data indicate that this combination therapy shows an adequate anti-relapse preclinical efficacy being able to overcome the preclinical limitations of NTX alone.

Multiple sclerosis in two patients with coexisting Wilson's disease

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.

Efficacy and safety of oral chelators in treatment of patients with Wilson disease

BACKGROUND & AIMS

Wilson disease is a genetic copper storage disorder that causes hepatic and neurologic symptoms. Chelating agents (D-penicillamine, trientine) are used as first-line therapies for symptomatic patients, but there are few data from large cohorts. We assessed the safety of D-penicillamine and trientine therapy and outcomes of patients with Wilson disease.

METHODS

We performed a retrospective analysis of data on 380 patients with Wilson disease from tertiary care centers in Germany and Austria, and 25 additional patients from the EUROWILSON registry. Chelator-based treatment regimens were analyzed for their effect on neurologic and hepatic symptoms and for adverse events that led to discontinuation of therapy (Kaplan-Meier estimation; data were collected for a mean of 13.3 y after therapy began).

RESULTS

Changes in medication were common, resulting in analysis of 471 chelator monotherapies (326 patients receiving D-penicillamine and 141 receiving trientine). Nine of 326 patients treated with D-penicillamine and 3 of 141 patients given trientine underwent liver transplantation. Adverse events leading to discontinuation of treatment were more frequent among those receiving D-penicillamine than trientine (P = .039). Forty-eight months after therapy, hepatic deterioration was reported in only 4 of 333 patients treated initially with a chelating agent. Hepatic improvements were observed in more than 90%, and neurologic improvements were observed in more than 55%, of therapy-naive patients, and values did not differ significantly between treatments. However, neurologic deterioration was observed less frequently in patients given D-penicillamine first (6 of 295) than those given trientine first (4 of 38; P = .018).

CONCLUSIONS

Chelating agents are effective therapies for most patients with Wilson disease; D-penicillamine and trientine produce comparable outcomes, although D-penicillamine had a higher rate of adverse events. Few patients receiving chelation therapy had neurologic deterioration, which occurred more frequently in patients who received trientine.

D-penicillamine-induced glomerulonephritis with crescent formation: Remission following drug discontinuation

We report a 71-year-old female who presented with rheumatoid arthritis complicated by proteinuria. She had been receiving D-penicillamine (D-Pc) for two years prior to presentation. A urinalysis showed proteinuria and hematuria which disappeared within 3 months after D-Pc was stopped. The renal histological findings showed focal proliferative glomerulonephritis with crescent formation. A total of 10 cases of D-Pc-induced glomerulonephritis with crescent formation without alveolar hemorrhage have previously been reported in the literature. To the best of our knowledge, this is the first case report in which the patient did not require any treatment.

D-penicillamine and other low molecular weight thiols: review of anticancer effects and related mechanisms

Low molecular weight thiols (LMWTs) like N-acetyl cysteine, D-penicillamine, captopril, Disulfiram and Amifostine, etc. have been used as chemo-preventive agents. Recent studies have reported cell growth inhibition and cytotoxicity in several different types of cancer cells following treatment with several LMWTs. Cytotoxic and cytostatic effects of LMWTs may involve interaction of the thiol group with cellular lipids, proteins, intermediates or enzymes. Some of the mechanisms that have been proposed include a p53 mediated apoptosis, thiyl radical induced DNA damage, membrane damage through lipid peroxidation, anti-angiogenic effects induced by inhibition of matrix metalloproteinase enzymes and angiostatin generation. LMWTs are strong chelators of transition metals like copper, nickel, zinc, iron and cobalt and may cause metal co-factor depletion resulting in cytotoxicity. Oxidation of thiol group can also generate cytotoxic reactive oxygen species (ROS).

Long-term effects of a combination of D-penicillamine and zinc salts in the treatment of Wilson's disease in children

The aim of this study was to investigate the effectiveness of a high-dose zinc sulfate and low-dose D-penicillamine combination in the treatment of pediatric Wilson's disease (WD). A retropective chart review of 65 patients with WD was conducted. These patients received D-penicillamine (8-10 mg/kg/day) and zinc sulfate as the primary treatment. The pediatric dose of elemental zinc is 68-85 mg/day until 6 years of age, 85-136 mg/day until 8 years of age, 136-170 mg/day until 10 years of age and then 170 mg/day, in 3 divided doses 1 h before meals. After clinical and biochemical improvement or stabilization, zinc sulfate alone was administered as the maintenance therapy. Under treatment, the majority of patients (89.2%) had a favourable outcome and 3 patients succumbed due to poor therapy compliance. No penicillamine-induced neurological deterioration was noted and side-effects were observed in <11% of patients over the entire follow-up period. Benefical results on the liver and neurological symptoms were reported following extremely long-term treatment with a combination of low-dose D-penicillamine and high-dose zinc sulfate. Therefore, this regimen is an effective and safe treatment for children with WD.