Treatment of Wilson's disease with triethylene tetramine hydrochloride (Trientine)

Trientine tetrahydrochloride versus penicillamine for maintenance therapy in Wilson disease (CHELATE): a randomised, open-label, non-inferiority, phase 3 trial

BACKGROUND

Wilson disease is an inherited disorder of copper transport. Whereas penicillamine is used therapeutically to re-establish copper balance, trientine is indicated for patients with penicillamine intolerance. We aimed to compare penicillamine with trientine tetrahydrochloride (TETA4) for maintenance therapy in patients with Wilson disease.

METHODS

We conducted a randomised, open-label, non-inferiority, phase 3 trial at 15 health-care centres across nine countries (patients were recruited from 13 of these health-care centres across Brazil, Europe, and the USA). We enrolled patients aged 18-75 years with stable Wilson disease who were treated for at least 1 year with penicillamine. Patients entered a 12-week period to determine stability through clinical assessment by site investigators and predefined thresholds for serum non-caeruloplasmin-bound copper (NCC; by an exchangeable copper assay; 25-150 μg/L), 24 h urinary copper excretion (100-900 μg/24 h), and alanine aminotransferase (ALT; <2 × upper limit of normal). Stable patients were randomly assigned (1:1) to continue receiving the maintenance twice daily dose of oral penicillamine or switched mg-for-mg to oral TETA4 centrally with a web-based system using minimisation. The primary endpoint, assessed 24 weeks after randomisation, was NCC by speciation assay. The non-inferiority margin of mean difference in NCC by speciation assay was -50 μg/L, as estimated by a general linear model for repeated visits, adjusted for baseline values. Further data on safety and efficacy were collected during a 24-week extension period. Data were analysed using an intention-to-treat approach. Safety was assessed in all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03539952 (active, not recruiting).

FINDINGS

Between June 4, 2018, and March 10, 2020, 77 patients were screened. 53 patients were randomly assigned (27 to the penicillamine group and 26 to the TETA4 group). After 24 weeks, the mean difference in serum NCC by speciation assay between the penicillamine group and TETA4 group was -9·1 μg/L (95% CI -24·2 to 6·1), with the lower limit of the 95% CI within the defined non-inferiority margin. At 24 weeks, urinary copper excretion was lower with TETA4 than with penicillamine (mean difference 237·5 μg/24 h (99% CI 115·6 to 359·4). At 48 weeks, TETA4 remained non-inferior to penicillamine in terms of NCC by speciation assay (mean difference NCC -15·5 μg/L [95% CI -34·5 to 3·6]). Urinary copper excretion at 48 weeks remained in the expected range for well treated patients in both study groups, and the mean difference (124·8 μg/24 h [99% CI -37·6 to 287·1]) was not significantly different. At 24 weeks and 48 weeks, masked clinical adjudication of stability assessed by three independent clinicians confirmed clinical stability (100%) of all participants, in agreement with the stability seen with the NCC by speciation assay. There were no notable changes in either the Clinical Global Impression of Change or Unified Wilson Disease Rating Scale (neurological assessment) from baseline (pre-randomisation) at weeks 24 and 48. The mean change in serum total copper from baseline to 24 weeks was 17·6 μg/L (99% CI -9·5 to 44·7) with penicillamine and -6·3 μg/L (-34·7 to 22·1) with TETA4, and the mean change in serum total caeruloplasmin from baseline to 24 weeks was 1·8 mg/L (-19·2 to 22·8) with penicillamine and -2·2 mg/L (-6·1 to 1·7) with TETA4. All liver enzymes were similar at 24 weeks and 48 weeks, with the exception of elevated ALT concentration at 48 weeks for patients in the TETA4 group. Penicillamine was associated with three post-randomisation serious adverse events (leukopenia, cholangiocarcinoma, and hepatocellular cancer); none were reported for TETA4. The most common treatment-emergent adverse events were headache for penicillamine (five [19%] of 27 patients vs two [8%] of 26) and abdominal pain for TETA4 (one [4%] vs four [15%]); all treatment-emergent adverse events resolved and were mild to moderate. One patient developed a rash with TETA4 that resolved on discontinuation of therapy.

INTERPRETATION

The efficacy of TETA4 as oral maintenance therapy was non-inferior to penicillamine and well tolerated in adults with Wilson disease.

FUNDING

Orphalan.

Multicentre, retrospective study to assess long-term outcomes of chelator based treatment with trientine in Wilson disease patients withdrawn from therapy with d -penicillamine

OBJECTIVES

Trientine dihydrochloride (TETA-2HCl) has been used for the treatment of Wilson disease for over 30 years. The current study was designed to systematically evaluate existing data to further define the long-term outcome of the efficacy and tolerability of TETA-2HCl in Wilson disease patients.

METHODS

Medical records of 77 Wilson disease patients were reviewed to collect data on hepatic and neurologic symptoms, copper (Cu) homeostasis and adverse events. Data were collected for 48 months after initiation of TETA-2HCl after withdrawal of D-penicillamine treatment.

RESULTS

Mean duration of TETA-2HCl treatment was 8 years (range 5 months-32.5 years). Over the course of TETA-2HCl treatment, 35% of patients had no hepatic symptoms whereas in 49.4% of patients, hepatic symptoms improved. They remained unchanged in 10.4% of patients and worsened in 5.2% of patients. No patients progressed to acute hepatic failure or necessity of a liver transplant. During TETA-2HCl treatment, 46.7% of patients had no neurologic symptoms; in 14.3% of patients, neurologic symptoms improved whereas in 36.4% of patients, they remained stable and worsened in 2.6% of patients. During the evaluation period, 12 patients discontinued TETA-2HCl treatment due to: anemia ( N = 1), inadequate hepatic response ( N = 2), switch to zinc treatment ( N = 8) and patient's decision to withdraw from treatment ( N = 1). Treatment-emergent adverse events were reported by 24.7% of the patients of which gastrointestinal disorders (9.1%) and nervous system disorders (5.2%) were most reported.

CONCLUSIONS

TETA-2HCl is well-tolerated and effective in Wilson disease patients following the withdrawal of treatment with D-penicillamine. ClinicalTrials.govIdentifier : NCT02426905.

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.

Optimized Trientine-dihydrochloride Therapy in Pediatric Patients With Wilson Disease: Is Weight-based Dosing Justified?

OBJECTIVES

The aim of the study was to investigate the efficacy and safety of trientine-dihydrochloride (TD) in pediatric patients with Wilson disease (WD) and the effect of different weight-based dosages on their clinical and biochemical outcome.

METHODS

We retrospectively reviewed the clinical data of 31 children with WD receiving TD therapy ages under 18 years at the time of diagnosis. Outcome measures included parameters of copper metabolism and liver function tests. To examine the impact of different weight-based dosages, 2 dosage subgroups were analyzed. Group 1 received less than 20 mg/kg TD per day, group 2 more than 20 mg · kg-1 · day-1.

RESULTS

Median follow-up was 60 (5-60) months in the total study group. During TD therapy, nonceruloplasmin-bound copper was reduced from mean 1.53 (0.01-6.95) at baseline to 0.62 (0.01-4.57) μmol/l. 24h-urinary copper excretion diminished to 1.85 (0.8-9.6) μmol/day approximating the therapeutic goal of 1.6 μmol/day. Seven of 31 patients (22.6%) required discontinuation of TD treatment, in 4 cases it was because of adverse events (ulcerative colitis, gingival and breast hypertrophy, hirsutism, elevation of transaminases).Investigations about weight-based dosage showed no significant difference of any laboratory parameter between the 2 cohorts. But in terms of clinical safety, adverse effects because of TD were only found in 6.7% of children in group 1 (<20 mg · kg-1 · day-1, median follow-up 60 [9-60] months), whereas in group 2 (>20 mg · kg-1 · day-1, median follow-up 60 [14-60] months), it was 63.6%.

CONCLUSIONS

TD proves to be an efficacious alternative chelating agent for children with WD. Weight-based dosages above the recommended 20 mg · kg-1 · day-1 may increase the rate of adverse effects in pediatric patients.

Switching Pharmacological Treatment in Wilson Disease: Case Report and Recommendations

Background. Available treatments for Wilson disease (WD) prevent longterm complications of copper accumulation. Current anti-copper agents include zinc salts, penicillamine, and trientine. Patients with WD may switch between the agents for a number of reasons. Due to the different mechanisms of action between the copper chelators and zinc salts, transitioning could require a period of overlap and increased monitoring. There are no large studies that investigate the best transition strategies between agents. In this article, we review the treatments for WD and how to monitor for treatment efficacy. Case Summary. The patient had been diagnosed with WD for over 20 years prior to establishing care in our Hepatology Clinic. During his initial course, he was transitioned from penicillamine to zinc due to evidence suggesting penicillamine had greater adverse effects in the long term. Later, he was switched to trientine. His liver enzymes and 24-hour urine copper were monitored. During these years, he intermittently had some financial hardship, requiring him to be on penicillamine rather than trientine. He also had developed acute kidney injury. Overall, his liver disease remained under control and he never had signs of decompensated cirrhosis, but had fluctuations of liver enzymes over the years. Conclusion. Anti-copper treatment for WD has to be tailored to medication side effects profile, patient's chronic and emerging comorbidities, as well as costs. Transitioning regimens is often challenging, and it requires closer monitoring, with no predictors of response.

A Dose Escalation Study of Trientine Plus Carboplatin and Pegylated Liposomal Doxorubicin in Women With a First Relapse of Epithelial Ovarian, Tubal, and Peritoneal Cancer Within 12 Months After Platinum-Based Chemotherapy

Background: Epithelial ovarian cancer (EOC) is the leading cause of gynecological cancer-related deaths worldwide. Preclinical studies found that copper-lowering agents could re-sensitize platinum-resistant cancer cells by enhancing the human copper transporter 1 (hCtr1)-mediated uptake of platinum. In the clinic, re-sensitization of platinum-resistance in relapsed EOC has been discovered by the application of trientine plus platinum (NCT01178112). However, no pharmacokinetic data of trientine has been reported in cancer patients.

Purpose: Our study aimed to explore the safety and activity of trientine combined with carboplatin and pegylated liposomal doxorubicin (PLD) in patients with EOC, tubal, and peritoneal cancer who experienced disease progression during platinum-based chemotherapy or showed relapse <12 months after completing first-line chemotherapy. Also, we aimed to demonstrate pharmacokinetic parameters and to discover potential biomarkers in our EOC patients.

Methods: In this dose escalation study, 18 Asian patients in six dosing cohorts received fixed doses of carboplatin (AUC 4) and PLD (LipoDox®, TTY Biopharm Co. Ltd., Taipei, Taiwan) (40 mg/m², day 1 per 4-week cycle), and escalated daily trientine doses (range: 300–1800 mg; initiated 7 days before the 1st combination cycle) according to a 3 + 3 design.

Results: No dose-limiting toxicity or treatment-related death was observed. Four patients (22.2%) developed grade 3 drug-related adverse events (AEs), whereas no grade 4 AEs were encountered. Anemia and grade 2 dizziness were the most common hematological toxicity and neurotoxicity, respectively. In a pharmacokinetics comparison with healthy volunteers in the literature, our patients achieved greater absorption after oral trientinem, and more rapid elimination of triethylenetetramine dihydrochloride at high doses. The clinical benefit rate was 33.3 and 50.0% in the platinum-resistant and the partially platinum-sensitive group, respectively. A high baseline serum iron level and low serum copper level might help differentiate subgroups of patients with different clinical responses. Nevertheless, no associations of the clinical response with the levels of serum hCtr1, ceruloplasmin, or copper were observed.

Conclusion: Combination therapy with carboplatin, trientine, and PLD was well-tolerated and safe. Our results encourage the development of a future phase II trial.

Clinical trial registration:ClinicalTrials.gov # NCT03480750.

A case report and focused literature review of d-penicillamine and severe neutropenia: A serious toxicity from a seldom-used drug

Prescribing d-penicillamine for Wilson's disease must be accompanied by vigilant monitoring, including a complete blood cell count with differential. For most, this should occur once or twice weekly during the first month of therapy and during periods of dose escalation, then every two weeks for six additional months, then monthly.

Advances in Treatment of Wilson Disease

Background

Wilson disease (WD) is an inherited neurometabolic disorder that results in excessive copper deposition in the liver and the brain, affecting children and young adults. Without treatment the disease is invariably fatal. Though treatments for WD have been available since the 1950s, the disease continues to be associated with considerable morbidity and mortality because of missed diagnosis, and delayed or inadequate treatment. In this paper we survey WD-related literature in order to review recent advances in WD treatment.

Methods

We performed a literature search using the PubMed database for articles relating to WD and its medical treatment. We reviewed the articles, and cross-references of relevant articles, to summarize the current practices for treatment of WD.

Results

The survey shows that if WD is properly treated, in most patients the liver can be stabilized, even severe neurological disability reversed, and patients can resume normal lives.

Discussion

Medical treatment for WD includes use of copper chelators (penicillamine, trientine, dimercaprol, dimercaptopropane sulfonate, and ammonium tetrathiomolybdate) and drugs that decrease gastrointestinal copper absorption. Our knowledge of the treatment approaches has benefited from the large systematic clinical studies that have been conducted over the last decade. For each drug used to treat WD, we surveyed its development, indication for use, dosing, efficacy, and adverse effects.

Wilson disease - currently used anticopper therapy

Wilson disease (WD) is a genetic disorder of copper metabolism that can be treated successfully with pharmacologic treatment. Two groups of drugs are currently used: chelators (e.g., d-penicillamine and trientine), which increase urinary copper excretion, and zinc salts, which inhibit copper absorption in the digestive tract. The mechanisms of action lead to a negative copper balance, stopping pathologic accumulation of copper in the tissues and clearing affected organs of copper overload. Due to a lack of prospective clinical trials, the use of drugs depends mainly on center experience and the accessibility in different countries or regions. This chapter presents the different reports and recommendations regarding WD treatment. In addition to the different expert opinions on pharmacologic agents, there are a few axioms regarding WD treatment: treatment should start immediately after diagnosis, even in clinically presymptomatic cases; the patient should be treated for life, making compliance a key factor in treatment success; and the treatment should be monitored regularly via liver and hematologic tests, neurologic examination, and copper metabolism, modifying the treatment accordingly. Other drugs proposed for WD treatment (e.g., tetrathiomolybdate) are in clinical trials and lack current recommendations. Thus, only the currently available options for WD pharmacologic treatment are discussed.

Combination Therapy Using Chelating Agent and Zinc for Wilson's Disease

There is no clear international consensus regarding the optimal medication therapy for treating Wilson's disease (WD). This study systematically reviews the effectiveness of various medication therapies in common use, specifically focusing on preliminary findings concerning the combination of a chelating agent and zinc. A systematic PubMed search was executed to locate original studies on the effectiveness of commonly used medications for WD published between January 1989 and August 2014. The results were used to conduct a systematic review of studies on combination therapies. A total of 17 combination therapy studies involving 1056 patients were reviewed. These were analyzed in terms of data on effectiveness, adverse effects, and mortality. Results from a pooled analysis indicate that combination therapies for hepatic patients were significantly less effective than the same therapies for neurological manifestations (47.1 vs. 78.6 %; pooled relative risk ratio (RR): 0.63, 95 % confidence interval CI 0.43-0.94; p = 0.02). Data from a subgroup analysis show that the combination therapy of penicillamine plus zinc sulfate resulted in a significantly higher mortality rate compared to all other combination therapy types (16.3 vs. 4.7 %; RR: 3.51, 95 % CI 1.54-8.00; p < 0.001). The use of combination therapies involving zinc and a chelator should be carefully monitored with close clinical observations and frequent biochemical tests, especially for WD patients with hepatic manifestations.

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.

Evolving perspectives in Wilson disease: diagnosis, treatment and monitoring

Wilson disease (WD), the autosomal recessively inherited copper overload disorder, remains a diagnostic and therapeutic challenge. In the last decade, direct sequencing of the affected gene ATP7B became commercially available, but interpretation of the results still requires careful attention. Thus, a combination of tests reflecting the disturbed copper metabolism is needed to make the final diagnosis. Because of the low disease frequency, the existing treatment concepts are not based on controlled trails. Here, recent outcome reports of larger cohort studies challenge the recommended therapies and call for individualized treatment strategies. The notion, that certain medical regimens may either be insufficient to upkeep copper homeostasis or may lead to a clinically relevant overtreatment, demand a continuous monitoring of patients even after decades of therapy. In this article, we review current diagnostic and therapeutic approaches in WD.

Zinc monotherapy is not as effective as chelating agents in treatment of Wilson disease

BACKGROUND & AIMS

Wilson disease is a genetic disorder that affects copper storage, leading to liver failure and neurologic deterioration. Patients are treated with copper chelators and zinc salts, but it is not clear what approach is optimal because there have been few studies of large cohorts. We assessed long-term outcomes of different treatments.

METHODS

Patients in tertiary care centers were retrospectively analyzed (n = 288; median follow-up time, 17.1 years) for adherence to therapy, survival, treatment failure, and adverse events from different treatment regimens (chelators, zinc, or a combination). Hepatic treatment failure was defined as an increase in activity of liver enzymes (aspartate aminotransferase, alanine aminotransferase, and γ-glutamyltransferase) >2-fold the upper limit of normal or >100% of baseline with an increase in urinary copper excretion.

RESULTS

The median age at onset of Wilson disease was 17.5 years. Hepatic and neuropsychiatric symptoms occurred in 196 (68.1%) and 99 (34.4%) patients, respectively. Hepatic treatment failure occurred more often from zinc therapy (14/88 treatments) than from chelator therapy (4/313 treatments; P < .001). Actuarial survival, without transplantation, showed an advantage for chelating agents (P < .001 vs zinc). Changes in treatment resulted mostly from adverse events, but the frequency did not differ between groups. Patients who did not respond to zinc therapy showed hepatic improvement after reintroduction of a chelating agent.

CONCLUSIONS

Treatments with chelating agents or zinc salt are effective in most patients with Wilson disease; chelating agents are better at preventing hepatic deterioration. It is important to identify patients who do not respond to zinc therapy and have increased activities of liver enzymes, indicating that a chelating agent should be added to the therapeutic regimen.

Triethylenetetramine pharmacology and its clinical applications

Triethylenetetramine (TETA), a Cu(II)-selective chelator, is commonly used for the treatment of Wilson's disease. Recently, it has been shown that TETA can be used in the treatment of cancer because it possesses telomerase inhibiting and anti-angiogenesis properties. Although TETA has been used in the treatment of Wilson's disease for decades, a comprehensive review on TETA pharmacology does not exist. TETA is poorly absorbed with a bioavailability of 8 to 30%. It is widely distributed in tissues with relatively high concentrations measured in liver, heart, and kidney. It is mainly metabolized via acetylation, and two major acetylated metabolites exist in human serum and urine. It is mainly excreted in urine as the unchanged parent drug and two acetylated metabolites. It has a relatively short half-life (2 to 4 hours) in humans. The most recent discoveries in TETA pharmacology show that the major pharmacokinetic parameters are not associated with the acetylation phenotype of N-acetyltransferase 2, the traditionally regarded drug acetylation enzyme, and the TETA-metabolizing enzyme is actually spermidine/spermine acetyltransferase. This review also covers the current preclinical and clinical application of TETA. A much needed overview and up-to-date information on TETA pharmacology is provided for clinicians or cancer researchers who intend to embark on cancer clinical trials using TETA or its close structural analogs.

Triethylene tetramine dihydrochloride (trientine) in children with Wilson disease: experience at King's College Hospital and review of the literature

Our aim was to review our experience of trientine as chelation therapy in children with Wilson disease (WD) and compare to that reported in the literature. We made a retrospective review of the medical notes of 16 of 96 (17%) children diagnosed with WD between 1981 and 2006. Children were 6.6 to 15 years old. Only three received trientine as initial therapy [parental choice (two), allergic reactions to penicillamine (one) during the penicillamine challenge], 13 of 16 were converted from penicillamine to trientine because of reactions to penicillamine: haematuria in four, bone marrow suppression in three, neutropenia in three. Trientine was discontinued in three due to allergic rash, low copper excretion and one with compliance problems requiring transplantation. Seventy-five per cent of children presented with chronic liver disease. Kayser-Fleischer rings were noticed in eight of 16, Wilson Ferenci score range was between 4 and 10 (nl < 4). Laboratory indices remained relatively stable. In line with previous reports, trientine was used mainly as secondary treatment when there were severe side effects with penicillamine. Whilst the current evidence is low quality, it appears that trientine is as efficacious as penicillamine and small population studies show a lower side effect profile.

Systematic review: clinical efficacy of chelator agents and zinc in the initial treatment of Wilson disease

BACKGROUND

No consensus is available on the optimal initial treatment in Wilson disease.

AIM

To assess systematically the available literature of treatment in newly presenting patients with a presymptomatic, hepatic or neurological presentation of Wilson disease.

METHODS

A systematic literature search of the MEDLINE, EMBASE and COCHRANE databases was performed. Original studies on clinical efficacy of D-penicillamine, trientine, tetrathiomolybdate or zinc monotherapy as initial treatment in Wilson disease were included. A descriptive analysis of the relevant published data was performed.

RESULTS

One randomized trial and 12 observational studies met the inclusion criteria. These studies were quite heterogeneous and generally of low validity. Nevertheless, according to currently available data, patients with hepatic presentation of Wilson disease are probably most effectively treated by D-penicillamine. Zinc seems to be preferred above d-penicillamine for treatment of presymptomatic and neurological patients, as in these subgroups, the tolerance profile is in favour of zinc, while no obvious differences in clinical efficacy could be observed.

CONCLUSIONS

There is lack of high-quality evidence to estimate the relative treatment effects of the available drugs in Wilson disease. Therefore, multicentre prospective randomized controlled comparative trials are necessary.

Wilson's Disease and Its Pharmacological Treatment

Wilson's disease is an inherited copper toxicosis caused by defective putative copper transporting ATPase in the liver. Because of impaired biliary secretion, copper remains in the liver, resulting in chronic hepatic lesions including fatty metamorphosis, chronic hepatitis and cirrhosis. In the latter stage, extrapyramidal syndromes may develop with and without symptomatic hepatic lesions. Acute liver damage associated with hemolysis and deep jaundice may be the first manifestation. The majority of patients show hypoceruloplasminemia, which has been used as a screening test for the disease. A large number of mutations in the ATP7B gene have been reported. Thus, genetic diagnosis might be limitedly used to presymptomatic diagnosis of siblings when mutations are identified in an index patient. Introduction of penicillamine caused a revolution in the treatment of patients. Another chelater, trientine, is now available for those intolerant of penicillamine. Tetrathiomolibdate and zinc acetate are additional alternatives currently being tested. Hypoceruloplasminemia and further reduction after chelation therapy may be associated with iron overload. This complication is closely related with impaired transport of ferrous ion due to ferroxidase deficiency. Noncompliance and teratogenicity are other major concerns because any treatment with the agents listed above is a life long regimen. Despite various side effects of penicillamine, its teratogenicity is negligible. These data indicate that penicillamine is the first choice of drug for this disease.

Linear polyamine copper chelator tetraethylenepentamine augments long-term ex vivo expansion of cord blood-derived CD34+ cells and increases their engraftment potential in NOD/SCID mice

OBJECTIVE

We previously demonstrated that cellular copper is involved in the regulation of proliferation and differentiation of hematopoietic progenitor cells. Modulation of cellular copper was achieved by supplementing the culture with a copper chelator that reduces cell copper content, or copper salts, which elevate the level of cellular copper. In the present study, we evaluated the effect of short-term (3-week) treatment with the copper chelator tetraethylenepentamine (TEPA) on short- and long-term (up to 11 weeks) ex vivo expansion of hematopoietic progenitors, as well as on their SCID engraftment potential.

MATERIALS AND METHODS

Cord blood-derived purified CD34+ cells were grown in liquid medium supplemented with the cytokines stem cell factor, thrombopoietin, Flt3 ligand, and IL-6, and the chelator TEPA for the first 3 weeks and then for up to 11 weeks with cytokines alone. Control cultures were supplemented with cytokines alone for the entire culture duration. Cultured cells were characterized by immunophenotyping and cloning (CFUc). Transplantability was assayed by injection of repurified CD34+ cells into NOD/SCID mice.

RESULTS

In the short term, TEPA supported increased percentages of early progenitors over control cultures incubated with cytokines alone (CD34(+)CD38-, p=0.001 and CD34(+)Lin-, p=0.016). In the long term, TEPA pretreated cultures showed prolonged expansion of CD34+ cells (p=0.01) and CFUc (p=0.002) compared with that of untreated cultures. The SCID engraftment potential of CD34+ cells repurified from the TEPA-treated cultures was higher compared with that of the control, i.e., only cytokine-treated cultures (p=0.03).

CONCLUSION

TEPA enabled preferential proliferation of early progenitor cells with the phenotype CD34(+)CD38- and CD34(+)CD38- Lin- during the first weeks of culture, resulting in the observed increased long-term ex vivo expansion and engraftment capabilities.

Enfermedad de Wilson con afectación neurológica grave: respuesta al tratamiento combinado con trientina y acetato de cinc

In patients with Wilson's disease and neurological manifestations, treatment with D-penicillamine can cause worsening of neurological symptoms, usually in the first few weeks of treatment. Because the neurological damage can be severe and irreversible, the use of D-penicillamine is controversial, and several authors believe that it should be avoided. Studies of the use of ammonium tetrathiomolybdate as an alternative chelating agent for the initial treatment of neurologic Wilson's disease are still in the experimental phase. Published experience on the simultaneous use of trientine, another chelating agent, and zinc, which blocks intestinal absorption of copper, is promising but limited. We present the case of a 17 year-old boy with severe neurologic Wilson's disease that had first presented six years previously. The patient showed a complete recovery after six months of treatment with a combination of trientine and zinc acetate.

Wilson disease

Wilson disease is a rare disorder of copper metabolism that results in accumulation of copper in the liver and subsequently in other organs, mainly the central nervous system and the kidneys. Advances in the diagnosis and treatment of Wilson disease are discussed, with the emphasis that this is a disease of children, adolescents, and young adults. The myriad manifestations of Wilson disease make its diagnosis dependent on a high index of suspicion, and determination of its genetic background is helping to elucidate the genotype-phenotype correlation and the diversity of presentations. Treatment of Wilson disease has progressed from chelation therapy using D-penicillamine and trientine to the more recent use of zinc and finally to the establishment of liver transplantation as an urgent but excellent modality for fulminant presentation. The evolution of Wilson disease from a uniformly fatal disease to an eminently treatable disease during the past century is an example of the remarkable advances of modern medicine.

Cellular copper content modulates differentiation and self-renewal in cultures of cord blood-derived CD34+ cells

Several clinical observations have suggested that copper (Cu) plays a role in regulating haematopoietic progenitor cell (HPC) development. To further study this role we used an ex vivo system. Cord blood-derived CD34+ cells were cultured in liquid medium supplemented with Kit- ligand, FLt3, interleukin 6 (IL-6), thrombopoietin and IL-3. Under these conditions, Cu content, measured by atomic absorption, was 7 ng/10(7) cells. Modulation of intracellular Cu was achieved by supplementing the cultures with the Cu chelator tetraethylenepentamine, which reduced cellular Cu (4 ng/10(7) cells), or ceruloplasmin or Cu sulphate that elevated cellular Cu (18 and 14 ng/10(7) cells respectively). The results indicated that low Cu content delayed differentiation, as measured by the surface antigens CD34, CD14 and CD15, colony-forming unit (CFU) frequency and cell morphology, while high Cu accelerated differentiation compared with Cu unmanipulated cultures. As a result, expansion of total cells, CFU and CD34+ cells in low Cu was extended (12-16 weeks), and in high Cu was shortened (2-4 weeks), compared with control cultures (6-8 weeks). These effects required modulation of intracellular Cu only during the first 1-3 weeks of the culture; the long-term effects persisted thereafter, suggesting that the decision process for either self-renewal or differentiation is taken early during the culture. This novel method of controlling cell proliferation and differentiation by copper and copper chelators might be utilized for ex vivo manipulation of HPC for various clinical applications.

Early onset of nephrotic syndrome after treatment with D-penicillamine in a patient with Wilson's disease

Wilson's disease responds to a variety of treatments including D-penicillamine and trientene. Nephrotic syndrome is a late complication of D-penicillamine treatment. We report a pediatric patient with Wilson's disease who developed nephrotic syndrome 2 wk after beginning D-penicillamine. His nephrosis resolved and his disease is quiescent with trientene treatment.

Wilson disease

Wilson disease is a recessively inherited disorder of copper transport. Clinical features are highly variable, with any combination of neurological, hepatic or psychiatric illness. The age of onset varies from 3 to 50 years of age. Diagnosis is challenging because no specific combination of clinical or biochemical features is necessarily definitive. The genetic defect is due to a variety of abnormalities in a copper-transporting membrane ATPase. Most of the more than 80 mutations are present at a low frequency, and mutations differ between ethnic groups. At least two mutations are sufficiently common to aid in rapid diagnosis, in European and Asian populations respectively. Molecular analysis can provide a definitive diagnosis for asymptomatic sibs. Treatment, using chelating agents or zinc, is most effective when started before permanent tissue damage occurs.

Acanthosis nigricans associated with hepatolenticular degeneration

Acanthosis nigricans and hepatolenticular degeneration (Wilson's disease) developed simultaneously in a 16-year-old boy. The diagnosis of Wilson's disease was based on the clinical presentation, including Kayser-Fleischer ring, hypoceruloplasminemia, hypocupremia, and hypercupriuria. His skin lesions were characterized by thick, dark brown, verrucous plaques on the dorsa of both feet, the neck, axillae, and groin. The histological findings were compatible with acanthosis nigricans. Six months after treatment with D-penicillamine, two grams per day, his skin lesions and neurological symptoms were much improved and no complications were observed.

Metabolism of administered triethylene tetramine dihydrochloride in humans

Triethylene tetramine dihydrochloride (trien 2HCl) has been used for the treatment of Wilson's disease, which is characterized by the accumulation of copper in various organs. We previously developed an HPLC system for analyzing trien, and found a trien metabolite in the urine when trien was orally given to humans. In this study, the metabolite was identified as 1-N-acetyltriethylene tetramine (acetyltrien) by FAB-MS and 1H-NMR spectroscopy. Trien and acetyltrien were capable of combining with copper, iron and zinc. However, the chelating activity of acetyltrien was significantly lower than that of trien. When trien was given to healthy adults, the amount of trien excreted in the urine was about 1% of the administered trien, whereas that of acetyltrien was about 8%. Most of the trien was excreted within the first 6 hours after the administration, while acetyltrien was excreted for over 26 hours. The urinary copper, iron and zinc levels all increased in parallel with the trien excretion.

Pediatric gastroenterology. Update on metabolic liver disease

Wilson's disease, genetic and neonatal hemochromatosis, protoporphyria, tyrosinemia, and alpha1-antitrypsin deficiency are updated. Cost effectiveness of screening is discussed. Current therapies are evaluated, including the role of transplantation. The molecular biologic technique PCR is covered. Gene therapy is introduced.

Neutropenia caused by copper deficiency: possible mechanisms of action

Although copper is an essential nutrient in the human diet, overt or severe copper deficiency is not a major public health concern in the United States. A marginal or borderline deficiency has been suggested by researchers, although the widespread nature of copper deficiency has yet to be established. Reports indicate that copper deficiency occurs secondary to gastric resection, unsupplemented total parenteral nutrition, high levels of zinc intake, or general malnutrition. An early clinical sign of copper deficiency is a reduction in the number of circulating neutrophils. Although copper is known to play a wide variety of roles in the organism and in the immune system, the molecular mechanism for copper-deficient neutropenia is not known. Very little data exist with which to examine this question. This paper will summarize our existing knowledge of the mechanism by which copper deficiency results in neutropenia. Although the data are scarce, analysis of this question will allow us to better understand additional molecular roles of this trace element, and, in turn, to promote an improved knowledge of immune cell functions and cellular differentiation.

Hepatic disorders. Features and appropriate management

The spectrum of liver disease is extremely wide, with many of the underlying disorders having acute and chronic presentations. Most of the underlying pathogenetic mechanisms are accounted for by autoimmune disease, viral infection and toxic insult. The management strategy of any liver disease is a combination of treating the symptoms and complications that arise, as well as drug therapies relevant to the specific underlying diagnosis. Encephalopathy, ascites, spontaneous bacterial peritonitis, variceal bleeding and pruritus are the main complications at which drug therapy is directed, although in some cases it represents only 1 aspect of the overall management. Drug therapy per se is largely ineffective in acute liver failure with the possible exception of acetylcysteine, but many drugs are used in the management of the constituent components of this complex medical emergency. Treatments for specific liver conditions are expanding, especially in the areas of autoimmune and viral disease. The increasing availability and success of liver transplantation has tended to change the emphasis of management, and it is often not appropriate to exhaust the treatment options before referring the patient for transplantation. A comprehensive review of all liver disease is beyond the scope of this article, but hopefully the important principles of management and commonly occurring clinical decisions are discussed.

Wilson's disease with cerebral manifestation: monitoring therapy by CSF copper concentration

The clinical courses, cerebrospinal fluid (CSF) and serum copper concentrations and urinary copper excretions under different schemes of drug treatment in four patients with cerebral manifestations of Wilson's disease were monitored over 6-11 years. CSF copper concentration measurements were performed from the beginning of therapy onwards in three patients and from 16 months after initial treatment onwards in the fourth. CSF copper levels decreased slowly over the years in parallel with clinical improvements, and increased in one patient who interrupted therapy for 2 years. These findings confirm our hypothesis that the concentration of copper in the CSF is a valuable quantitative parameter reflecting the normalization of copper in the brain. Copper measurements during phases of initial neurological deterioration in two patients receiving D-penicillamine, and in one patient receiving D-penicillamine and zinc sulphate, revealed decreased free serum copper and CSF copper levels.

Magnetic resonance imaging of the brain in Wilson's disease

Eight patients with Wilson's disease (WD) were studied by magnetic resonance imaging (MRI) of the brain; seven also underwent X-ray computed tomography (CT) of the brain. We describe the changes in the brain and try to correlate them with the clinical manifestations and progress of the disease. Six patients were symptomatic, with predominantly neurological problems. Two were asymptomatic, diagnosed upon screening siblings of index cases. Of the six symptomatic patients, five had basal ganglia lesions, combined in four with brain stem changes; in one with only brain stem abnormalities, clinical findings were minimal despite pronounced MRI changes. In three patients MRI abnormalities regressed following chelating therapy. MRI can contribute to documentation of early neurological involvement in WD, especially in patients with no abnormalities on CT. However, MRI changes may not correlate with clinical presentation or response to therapy.

Acquired sideroblastic anaemia during treatment of Wilson's disease with triethylene tetramine dihydrochloride

We report one case of acquired sideroblastic anaemia in a patient treated for Wilson's disease with triethylene tetramine dihydrochloride (TTH). No other cause of acquired sideroblastic anaemia was found, and neither iron nor pyridoxine therapy could correct this anaemia. In contrast, decreasing the dose of TTH led to disappearance of ringed sideroblasts. Thus TTH should be added as a further cause of secondary acquired sideroblastic anaemia. The pathophysiology of this finding, probably linked to an abnormality of mitochondrial iron metabolism, is briefly discussed.