Effects of trientine and penicillamine on intestinal copper uptake: A mechanistic 64 Cu PET/CT study in healthy humans.

BACKGROUND AND AIMS: Trientine (TRI) and D-penicillamine (PEN) are used to treat copper overload in Wilson disease. Their main mode of action is thought to be through the facilitation of urinary copper excretion. In a recent study, TRI was noninferior to PEN despite lower 24-hour urinary copper excretion than PEN. We tested whether TRI and/or PEN also inhibit intestinal copper absorption. APPROACH AND RESULTS: Sixteen healthy volunteers were examined with positron emission tomography (PET)/CT 1 and 15 hours after an oral Copper-64 ( 64 Cu) dose. They then received 7 days of either PEN or TRI (trientine tetrahydrochloride), after which the 64 Cu PET/CT scans were repeated. Venous blood samples were also collected. Pretreatment to posttreatment changes of the hepatic 64 Cu uptake reflect the effect of drugs on intestinal absorption. 64 Cu activity was normalized to dose and body weight and expressed as the mean standard uptake value. TRI (n=8) reduced hepatic 64 Cu activity 1 hour after 64 Cu dose from 6.17 (4.73) to 1.47 (2.97) standard uptake value, p <0.02, and after 15 hours from 14.24 (3.09) to 6.19 (3.43), p <0.02, indicating strong inhibition of intestinal 64 Cu absorption. PEN (n=8) slightly reduced hepatic standard uptake value at 15 hours, from 16.30 (5.63) to 12.17 (1.44), p <0.04. CONCLUSIONS: In this mechanistic study, we show that TRI inhibits intestinal copper absorption, in addition to its cupriuretic effect. In contrast, PEN has modest effects on the intestinal copper absorption. This may explain why TRI and PEN are equally effective although urinary copper excretion is lower with TRI. The study questions whether the same therapeutic targets for 24-hour urinary excretion apply to both drugs.

Early neurological deterioration in Wilson's disease: a systematic literature review and meta-analysis.

INTRODUCTION: Neurological deterioration, soon after anti-copper treatment initiation, is problematic in the management of Wilson's disease (WD) and yet reports in the literature are limited. The aim of our study was to systematically assess the data according to early neurological deteriorations in WD, its outcome and risk factors. METHODS: Using PRISMA guidelines, a systematic review of available data on early neurological deteriorations was performed by searching the PubMed database and reference lists. Random effects meta-analytic models summarized cases of neurological deterioration by disease phenotype. RESULTS: Across the 32 included articles, 217 cases of early neurological deterioration occurred in 1512 WD patients (frequency 14.3%), most commonly in patients with neurological WD (21.8%; 167/763), rarely in hepatic disease (1.3%; 5/377), and with no cases among asymptomatic individuals. Most neurological deterioration occurred in patients treated with d-penicillamine (70.5%; 153/217), trientine (14.2%; 31/217) or zinc salts (6.9%; 15/217); the data did not allow to determine if that reflects how often treatments were chosen as first line therapy or if the risk of deterioration differed with therapy. Symptoms completely resolved in 24.2% of patients (31/128), resolved partially in 27.3% (35/128), did not improve in 39.8% (51/128), with 11 patients lost to follow-up. CONCLUSIONS: Given its occurrence in up to 21.8% of patients with neurological WD in this meta-analysis of small studies, there is a need for further investigations to distinguish the natural time course of WD from treatment-related early deterioration and to develop a standard definition for treatment-induced effects.

Rationale and design of a randomised trial of trientine in patients with hypertrophic cardiomyopathy.

AIMS: Hypertrophic cardiomyopathy (HCM) is characterised by left ventricular hypertrophy (LVH), myocardial fibrosis, enhanced oxidative stress and energy depletion. Unbound/loosely bound tissue copper II ions are powerful catalysts of oxidative stress and inhibitors of antioxidants. Trientine is a highly selective copper II chelator. In preclinical and clinical studies in diabetes, trientine is associated with reduced LVH and fibrosis, and improved mitochondrial function and energy metabolism. Trientine was associated with improvements in cardiac structure and function in an open-label study in patients with HCM. METHODS: The Efficacy and Mechanism of Trientine in Patients with Hypertrophic Cardiomyopathy (TEMPEST) trial is a multicentre, double-blind, parallel group, 1:1 randomised, placebo-controlled phase II trial designed to evaluate the efficacy and mechanism of action of trientine in patients with HCM. Patients with a diagnosis of HCM according to the European Society of Cardiology Guidelines and in New York Heart Association classes I-III are randomised to trientine or matching placebo for 52 weeks. Primary outcome is change in left ventricular (LV) mass indexed to body surface area, measured using cardiovascular magnetic resonance. Secondary efficacy objectives will determine whether trientine improves exercise capacity, reduces arrhythmia burden, reduces cardiomyocyte injury, improves LV and atrial function, and reduces LV outflow tract gradient. Mechanistic objectives will determine whether the effects are mediated by cellular or extracellular mass regression and improved myocardial energetics. CONCLUSION: TEMPEST will determine the efficacy and mechanism of action of trientine in patients with HCM. TRIAL REGISTRATION NUMBERS: NCT04706429 and ISRCTN57145331.

Triethylenetetramine (TETA).

The WEEL for triethylenetetramine (TETA; CAS No. 112-24-3) was originally established in 1991 and updated in 1998 and 2009. Recent literature searches to identify new toxicity information were performed in 2016 and January 2021. No new studies or data relevant to the WEEL were identified. TETA is used in manufacturing; the hydrochloride salt of TETA is used as a copper-chelating drug in the treatment of Wilson's disease. TETA is severely irritating to the skin and eyes and produces skin sensitization; however, it is of low to moderate acute toxicity via the oral and dermal routes of exposure. In subchronic studies, signs of toxicity included multi-organ effects (lung, liver, and spleen) in mice, but not rats. TETA was genotoxic/mutagenic in short-term in vitro assays but not in in vivo assays. No data on reproductive toxicity were available. Embryo/fetal toxicity occurred at maternally toxic doses and was associated with copper deficiency. In humans, the use of TETA·2HCl for treatment of Wilson's disease during pregnancy resulted in no miscarriages or fetal abnormalities. No evidence of carcinogenicity was noted in a lifetime dermal study in mice. Based on a subchronic drinking water study in mice, 600 ppm (95 mg/kg-day) was determined to be the no-observed-adverse-effect level (NOAEL) and the point of departure (POD). This NOAEL was converted to an equivalent inhalation concentration by adjusting for respiratory rate, interindividual variability, and uncertainty. The resulting 8-h time-weighted average WEEL value of 1 ppm is expected to provide a significant margin of safety against any potential adverse health effects in workers exposed to airborne TETA.

Treatment of Superficial Necrolytic Dermatitis with Copper Chelationina Dog with Copper-Associated Hepatitis.

A 7 yr old castrated male Cavalier King Charles spaniel presented for evaluation of liver enzyme elevations. Abdominal ultrasound revealed a small liver with mixed echogenicity, small hypoechoic nodules, and an irregular surface. Histologic examination and copper quantification of the liver obtained by laparoscopy diagnosed copper-associated hepatitis. One month later the dog developed hyperkeratosis of all four foot pads and ulcerations of feet, legs, and rectum. Punch biopsies confirmed superficial necrolytic dermatitis. After a total of 2 mo of chelation with no changes to medications, skin lesions began to improve, continuing over the following 6 wk to almost complete resolution. At this point the skin lesions returned and had minimal response to four amino acids infusions. The dog was switched from penicillamine to trientine. Zinc acetate was initiated 6 wk after the switch to trientine, and skin improvement was noted soon thereafter. At the time of death, skin lesions were improving and the dog was clinically comfortable. Copper-associated hepatitis should be considered as a possible etiology for superficial necrolytic dermatitis. Treatment of superficial necrolytic dermatitis is often unrewarding, and copper chelation, when copper-associated hepatitis has been confirmed, represents another therapeutic option.

AKT-driven epithelial-mesenchymal transition is affected by copper bioavailability in HER2 negative breast cancer cells via a LOXL2-independent mechanism.

BACKGROUND: The main mechanism underlying cancer dissemination is the epithelial to mesenchymal transition (EMT). This process is orchestrated by cytokines like TGFß, involving "non-canonical" AKT- or STAT3-driven pathways. Recently, the alteration of copper homeostasis seems involved in the onset and progression of cancer. METHODS: We expose different breast cancer cell lines, including two triple negative (TNBC) ones, an HER2 enriched and one cell line representative of the Luminal A molecular subtype, to short- or long-term copper-chelation by triethylenetetramine (TRIEN). We analyse changes in the expression of EMT markers (E-cadherin, fibronectin, vimentin and αSMA), in the levels and activity of extracellular matrix components (LOXL2, fibronectin and MMP2/9) and of copper homeostasis markers by Western blot analyses, immunofluorescence, enzyme activity assays and RT-qPCR. Boyden Chamber and wound healing assays revealed the impact of copper chelation on cell migration. Additionally, we explored whether perturbation of copper homeostasis affects EMT prompted by TGFß. Metabolomic and lipidomic analyses were applied to search the effects of copper chelation on the metabolism of breast cancer cells. Finally, bioinformatics analysis of data on breast cancer patients obtained from different databases was employed to correlate changes in kinases and copper markers with patients' survival. RESULTS: Remarkably, only HER2 negative breast cancer cells differently responded to short- or long-term exposure to TRIEN, initially becoming more aggressive but, upon prolonged exposure, retrieving epithelial features, reducing their invasiveness. This phenomenon may be related to the different impact of the short and prolonged activation of the AKT kinase and to the repression of STAT3 signalling. Bioinformatics analyses confirmed the positive correlation of breast cancer patients' survival with AKT activation and up-regulation of CCS. Eventually, metabolomics studies demonstrate a prevalence of glycolysis over mitochondrial energetic metabolism and of lipidome changes in TNBC cells upon TRIEN treatment. CONCLUSIONS: We provide evidence of a pivotal role of copper in AKT-driven EMT activation, acting independently of HER2 in TNBC cells and via a profound change in their metabolism. Our results support the use of copper-chelators as an adjuvant therapeutic strategy for TNBC.

Novel melatonin-trientine conjugate as potential therapeutic agents for Alzheimer's disease.

Researchers continue to explore drug targets to treat the characteristic pathologies of Alzheimer's disease (AD). Some drugs relieve the pathological processes of AD to some extent, but the failed clinical trials indicate that multifunctional agents seem more likely to achieve the therapy goals for this neurodegenerative disease. Herein, a novel compound named melatonin-trientine (TM) has been covalently synthesized with the natural antioxidant compounds melatonin and the metal ion chelator trientine. After toxicological and pharmacokinetic verification, we elucidated the effects of intraperitoneal administration of TM on AD-like pathology in 6-month-old mice that express both the ß-amyloid (Aß) precursor protein and presenilin-1 (APP/PS1). We found that TM significantly decreased Aß deposition and neuronal degeneration in the brains of the APP/PS1 double transgenic mice. This result may be due to the upregulation of iron regulatory protein-2 (IRP2), insulin degrading enzyme (IDE), and low density lipoprotein receptor related protein 1 (LRP1), which leads to decreases in APP and Aß levels. Additionally, TM may promote APP non-amyloidogenic processing by activating the melatonin receptor-2 (MT2)-dependent signaling pathways, but not MT1. In addition, TM plays an important role in blocking γ-secretase, tau hyperphosphorylation, neuroinflammation, oxidative stress, and metal ion dyshomeostasis. Our results suggest that TM may effectively maximize the therapeutic efficacy of targeting multiple mechanisms associated with AD pathology.

Wilson Disease in Children.

The silver anniversary of the discovery of the Wilson disease gene ATP7B was a couple of years ago, and we continue to make progress both in our understanding of copper transportation using animal models as well as earlier diagnosis by availing of genetic testing. Wilson disease is multisystemic and the hepatic manifestations are seen more frequently in childhood, whereas neurologic manifestations are more common in adults; presentation may range from subtle changes to end-stage liver disease with or without encephalopathy as well as neuropsychiatric manifestations. Treatment remains with zinc and chelating agents such as D-penicillamine and trientine but newer agents and gene therapy are in clinical trials. Liver transplantation becomes necessary when medical therapy is not enough. Molecular diagnosis and genetic counseling is important.

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.

N,N'-1,10-Bis(Naringin) Triethylenetetraamine, Synthesis and as a Cu(II) Chelator for Alzheimer's Disease Therapy.

The bis-Schiff base of N,N'-1,10-bis(naringin) triethylenetetraamine (1) was prepared, as a copper(II) ion chelator, compound 1 was used for Alzheimer's disease therapy in vitro. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay of compound 1 showed that this Schiff base could promote PC12 cells proliferation, and also, compound 1 could inhibit Cu2+-amyloid-ß (Aß)1-42 mediated cytotoxicity on PC12 cells. The thioflavine T (ThT) assay showed that 1 can effectively attenuate Cu2+-induced Aß1-42 aggregation. In addition, compound 1 is determined to be potent antioxidants on the basis of in vitro antioxidant assay, it can effectively decease the level of reactive oxygen species (ROS) in Cu2+-Aß1-42-treated PC12 cells and elevate the superoxide dismutase (SOD) activity in Cu2+-Aß1-42-treated PC12 cells. The results show that N,N'-1,10-bis(naringin) triethylenetetraamine is a potential agent for therapy of Alzheimer's disease.

[Retrospective cross-sectional study based on nationwide data of drug prescriptions and contractional data of outpatient offices regarding Morbus Wilson's disease]. / Retrospektive Querschnittsstudie von bundesweiten Arzneiverordnungsdaten und vertragsärztlichen Abrechnungsdaten von Morbus Wilson.

INTRODUCTION: In this article, the prevalence of the Morbus Wilson disease in Germany is determined. This is based on nationwide data of drug prescriptions and contractional data of outpatient offices. The prevalence is set in ratio to the found prevalence of prescriptions in Germany. METHOD: The descriptive evaluation is based on the database of the Central Research Institute of Ambulatory Health Care (Zi) in Germany. Additionally, data of the Federal Office of Statistics regarding inpatient treatment are available. RESULTS: It can be seen that there is a notable difference between the prevalence of patients undergoing therapy and the patients with verified diagnoses. In total, prevalence is increasing. The incidence on hand and the given dynamic of the patient population could indicate that, possibly, there is an increased rate of misdiagnosis in the first year of diagnosis. According to data, the hepatic form is the more often diagnosed form. The human genetic diagnostic increases, on average, are most distinct. ATTRIBUTES: Wilson Disease, Prevalence, Incidence, Trientine, Trientintetrahydrochlorid, D-Penicillamin, Zinc acetat, Zinc.

Idiopathic copper toxicosis: is abnormal copper metabolism a primary cause of this disease?

Idiopathic copper toxicosis (ICT) is characterized by marked copper deposition, Mallory-Denk body (MDB) formation and severe hepatic injury. Although the characteristics are apparently different from Wilson disease, large amounts of copper accumulate in the liver of the patients. We extensively treated a patient with ICT to reduce the body copper, however, the patient needed liver transplantation. Previous liver biopsy revealed high copper content. But extirpated liver contained an extremely small amount of copper, although MDBs and severe inflammation remained. These phenomena suggest abnormal copper metabolism is not the principle cause of ICT but some other abnormality must exist.

Comparative effectiveness of common therapies for Wilson disease: A systematic review and meta-analysis of controlled studies.

BACKGROUND & AIMS: Wilson disease (WD) is a rare disorder of copper metabolism. The objective of this systematic review was to determine the comparative effectiveness and safety of common treatments of WD. METHODS: We included WD patients of any age or stage and the study drugs D-penicillamine, zinc salts, trientine and tetrathiomolybdate. The control could be placebo, no treatment or any other treatment. We included prospective, retrospective, randomized and non-randomized studies. We searched Medline and Embase via Ovid, the Cochrane Central Register of Controlled Trials, and screened reference lists of included articles. Where possible, we applied random-effects meta-analyses. RESULTS: The 23 included studies reported on 2055 patients and mostly compared D-penicillamine to no treatment, zinc, trientine or succimer. One study compared tetrathiomolybdate and trientine. Post-decoppering maintenance therapy was addressed in one study only. Eleven of 23 studies were of low quality. When compared to no treatment, D-penicillamine was associated with a lower mortality (odds ratio 0.013; 95% CI 0.0010 to 0.17). When compared to zinc, there was no association with mortality (odds ratio 0.73; 95% CI 0.16 to 3.40) and prevention or amelioration of clinical symptoms (odds ratio 0.84; 95% CI 0.48 to 1.48). Conversely, D-penicillamine may have a greater impact on side effects and treatment discontinuations than zinc. CONCLUSIONS: There are some indications that zinc is safer than D-penicillamine therapy while being similarly effective in preventing or reducing hepatic or neurological WD symptoms. Study quality was low warranting cautious interpretation of our findings.

Long-term evaluation of urinary copper excretion and non-caeruloplasmin associated copper in Wilson disease patients under medical treatment.

OBJECTIVE: Urinary copper excretion rates and non-caeruloplasmin associated copper concentrations are increased in patients with Wilson disease. However, there is little literature describing the monitoring of these parameters over the long term. METHODS: This is a monocentric retrospective study including data collected between 2003 and 2015 from 321 patients with Wilson disease by chart review. The patients were under therapy with D-penicillamine, trientine, or zinc. 24-h urinary copper excretion rates, non-caeruloplasmin associated copper, and total serum copper concentrations were determined at the start of therapy, as well as 6, 12, 18, 24, 36, and ≥ 60 months after the start of therapy. For patients taking chelating agents, all parameters were measured while under continued therapy, as well as after a 48-h dose interruption. A mathematical formula to predict 24-h urinary copper excretion rates under different therapies was established. RESULTS: In all treatment groups, urinary copper excretion rates decreased over time, but the inter-individual variation of the results was high. Non-caeruloplasmin associated copper concentrations tended to decline over time, but with a higher variation of results than that observed for urinary copper excretion rates. CONCLUSION: Due to their variability, urinary copper excretion rates and serum copper concentrations are less than ideal parameters by which to monitor the benefit of a copper-reducing therapy. Urinary copper excretion rates seem to be more suitable than non-caeruloplasmin associated copper concentrations for this purpose.

Immunoglobulin A nephropathy secondary to Wilson's disease: a case report and literature review.

Immunoglobulin A nephropathy is the most common primary glomerulonephritis worldwide, and it can be associated with liver disease. However, cases of Immunoglobulin A nephropathy secondary to Wilson's disease are very rare. A 20-year-old Japanese man presented with microscopic hematuria, proteinuria, and renal dysfunction. A renal biopsy showed mesangial cell proliferation, immunoglobulin A deposition, and electron-dense deposit in the mesangial areas, all of which are consistent with Immunoglobulin A nephropathy. Computed tomography of the abdomen showed liver atrophy and splenomegaly, and the diagnosis of Wilson's disease was confirmed with decreased serum ceruloplasmin levels, increased urinary copper excretion, Kayser-Fleischer rings and copper deposition in the liver biopsy. The patient was treated successfully with trientine hydrochloride and zinc acetate and showed improvement in renal manifestations. Wilson's disease is a rare cause of secondary Immunoglobulin A nephropathy. We recommend that Wilson's disease should be considered the cause of secondary Immunoglobulin A nephropathy in juvenile patients with hematuria, proteinuria, and splenomegaly and suggest measuring the serum ceruloplasmin concentrations, urinary copper excretion, and evaluating Kayser-Fleischer rings in these patients.

Pregnancy in Wilson's disease: Management and outcome.

Wilson's disease (WD) is a rare inherited disorder of copper metabolism causing toxic hepatic and neural copper accumulation. Clinical symptoms vary widely, from asymptomatic disease to acute liver failure or chronic liver disease with or without neuropsychiatric symptoms. Continuation of specific medical treatment for WD is recommended during pregnancy, but reports of pregnancy outcomes in WD patients are sparse. In a retrospective, multicenter study, 282 pregnancies in 136 WD patients were reviewed. Age at disease onset, age at conception, and WD-specific treatments were recorded. Maternal complications during pregnancy, rate of spontaneous abortions, and birth defects were analyzed with respect to medical treatment during pregnancy. Worsening of liver function tests was evident during 16 of 282 (6%) pregnancies and occurred in undiagnosed patients as well as in those under medical treatment. Liver test abnormalities resolved in all cases after delivery. Aggravation of neurological symptoms during pregnancy was rare (1%), but tended to persist after delivery. The overall spontaneous abortion rate in the study cohort was 73 of 282 (26%). Patients with an established diagnosis of WD receiving medical treatment experienced significantly fewer spontaneous abortions than patients with undiagnosed WD (odds ratio, 2.853 [95% confidence interval, 1.634-4.982]). Birth defects occurred in 7 of 209 (3%) live births. CONCLUSION: Pregnancy in WD patients on anticopper therapy is safe. The spontaneous abortion rate in treated patients was lower than that in therapy-naïve patients. Although the teratogenic potential of copper chelators is a concern, the rate of birth defects in our cohort was low. Treatment for WD should be maintained during pregnancy, and patients should be monitored closely for hepatic and neurological symptoms. (Hepatology 2018;67:1261-1269).

Modality of treatment and potential outcome of Wilson disease in Taiwan: A population-based longitudinal study.

BACKGROUND/PURPOSE: This study aimed to investigate the epidemiology, the preference of medication, and the potential outcome of Wilson disease in Taiwan. We aimed to provide better therapeutic options for patients with Wilson disease based on the data generated from this study. METHODS: We utilized the National Health Insurance Research Database (NHIRD), which stores clinical records of nearly 99% of Taiwan's residents. The database used is a random sample of two-million out of 23-million beneficiaries in Taiwan's NHIRD in 2005. The integrated medical records of these two-million cases were collected from 2000 to 2011. Subjects of Wilson disease were identified as those with International Classification of Diseases, Ninth Revision (ICD-9) code 275.1 and the specific prescription drugs (including d-penicillamine, zinc, and trientine) in either outpatient clinic or inpatient records. RESULTS: During the study period, 66 cases of Wilson disease were identified. The male to female ratio was 1.75. The average prevalence rate was 1.81 per 100,000 and the average annual diagnosis rate was 0.22 per 100,000. The diagnosis was mostly established at 20-24 and 10-14 years of age, followed by 25-29 years. Fifty four of all subjects (81.8%) started the treatment with d-penicillamine, compared with zinc (12.1%) and trientine (6.1%). Among these 66 cases, 27 (40.9%) had liver cirrhosis and three (4.5%) underwent liver transplantation due to liver failure. CONCLUSION: d-penicillamine is still the most popular prescription of Wilson disease, followed by zinc monotherapy. Although chronic liver injury cannot be avoided, a favorable potential outcome is well demonstrated in this population-based study.

Wilson Disease: Diagnosis, Treatment, and Follow-up.

Consideration of a diagnosis of Wilson disease is still the critical factor in testing for and establishing disease diagnosis. In association with other clinical and biochemical tests, liver biopsy results and molecular genetic testing can also be used to generate a score for diagnosing Wilson disease. Medical therapy is effective for most patients; liver transplant can rescue those with acute liver failure or those with advanced liver disease who fail to respond to or discontinue medical therapy. Treatment monitoring must be done at regular intervals and includes clinical evaluation, liver tests and blood counts, and copper metabolic parameters.