Zinc Therapy for Wilson Disease in Children in French Pediatric Centers

Challenges in pediatric inherited/metabolic liver disease: Focus on the disease spectrum, diagnosis and management of relatively common disorders

The clinical scenario of pediatric liver disease is becoming more intricate due to changes in the disease spectrum, in which an increasing number of inherited/ metabolic liver diseases are reported, while infectious diseases show a decreasing trend. The similar clinical manifestations caused by inherited/metabolic diseases might be under-recognized or misdiagnosed due to nonspecific characteristics. A delayed visit to a doctor due to a lack of symptoms or mild symptoms at an early stage will result in late diagnosis and treatment. Moreover, limited diagnostic approaches, especially liver biopsy, are not easily accepted by pediatric patients, leading to challenges in etiological diagnosis. Liver dysfunction due to inherited/metabolic diseases is often caused by a variety of metabolites, so precision treatment is difficult; symptomatic treatment is a compelling option for inherited disorders.

Neurological Wilson's Disease Signs-Hepatic Encephalopathy or Copper Toxicosis?

Wilson's disease (WD) is a rare autosomal recessive (AR) disorder resulting from mutations in the ATP7B gene, which is responsible for the encryption of transmembrane copper transporting ATPase. The symptomatic presentation of the disease is estimated to be about 1 in 30,000. The impairment of ATP7B function results in a copper overload in hepatocytes, which further leads to liver pathology. This copper overload also occurs in other organs, most particularly in the brain. This could then cause the occurrence of neurological and psychiatric disorders. Symptoms differ substantially and most often occur between the ages of 5 and 35 years. Early symptoms are commonly hepatic, neurological, or psychiatric. While disease presentation is most often asymptomatic, it could also range as far as to include fulminant hepatic failure, ataxia, and cognitive disorders. Various treatments are available for Wilson's disease, including chelation therapy and zinc salts, which can reverse copper overload through different mechanisms. In select cases, liver transplantation is recommended. New medications, such as tetrathiomolybdate salts, are currently being investigated in clinical trials. With prompt diagnosis and treatment, prognosis is favorable; however, diagnosing patients before the onset of severe symptoms is a significant concern. Early screening for WD could help in diagnosing patients earlier and improving treatment outcomes.

Zinc Acetate Dihydrate Tablet-Associated Gastritis Occurring in a Post-Hematopoietic Stem Cell Transplant Recipient

A 65-year-old Japanese woman underwent umbilical cord blood transplantation for acute myeloid leukemia. Zinc acetate dihydrate tablets were administered for hypozincemia after transplantation, and vomiting and appetite loss occurred soon thereafter. Esophagogastroduodenoscopy revealed mucosal redness, erosion, white coat adhesion, and ulcers. Although graft-versus-host disease, intestinal transplant-associated microangiopathy, and cytomegalovirus infection were considered as possible causes, we diagnosed the patient with zinc acetate dihydrate tablet-associated gastric mucosal alterations based on the endoscopic features. This case reinforces the notion that medication-associated gastric lesions should be suspected in patients taking zinc acetate dihydrate tablets.

Low Copper Diet—A Therapeutic Option for Wilson Disease?

Wilson’s disease (WD) is an autosomal recessive inherited disease in which a pathological storage of copper in various organs is the mean pathophysiological mechanism. The therapy consists of drug therapy with chelating agents or zinc. For patients, nutrition is always an important issue. The aim of this review was to determine whether there are clear recommendations for a low copper diet for WD patients, or whether the essential trace element zinc plays a role? We were able to show that some of the foods with high copper content would have to be consumed in such large quantities that this is regularly not the case. Furthermore, there are also different absorption rates depending on the copper content. A lower copper intake only prevents the re-accumulation of copper. In summary, consistent adherence to drug therapy is more important than a strict diet. Only two foods should be consistently avoided: Liver and Shellfish.

Efficacy and Safety of Two Salts of Trientine in the Treatment of Wilson’s Disease

Background: Wilson’s disease (WD) is one of the few genetic disorders that can be successfully treated with pharmacological agents. Copper-chelating agents (D-penicillamine and Trientine salts) and zinc salts have been demonstrated to be effective. There are two salts of trientine. Trientine dihydrochloride salt (TETA 2HCL) is unstable at room temperature and requires storage at 2–8 °C. Trientine tetrahydrochloride (TETA 4HCL) is a more stable salt of trientine that can be stored at room temperature. No comparative study between both of the salts of trientine has been performed to date. As the two chemical forms were available in France between 1970 and 2009, we conducted a study to evaluate their efficacy and safety profiles. Methods: This retrospective cohort study was conducted by reviewing data from the national WD registry in France. Forty-three WD patients who received TETA 2HCL or TETA 4HCL monotherapy for at least one year until 2010 were included. The primary endpoints were hepatic and neurological outcomes. Secondary endpoints were the events leading to a discontinuation of medication. Results: Changes in medication were common, leading to the analysis of 57 treatment sequences of TETA 4HCL or TETA 2HCL. The mean duration of treatment sequence was significantly longer in the TETA 4 HCL group (12.6 years) than in the TETA 2HCL group (7.6 years) (p = 0.011). Ten patients experienced both trientine salts: eight stopped TETA 4 HCL (six had a hepatologic phenotype and two had a neurological phenotype) because this treatment was not available anymore (mean duration 7.4 years). Three of these patients already experienced TETA 2 HCL before the sequence. Two patients with a hepatologic phenotype (one had a previous sequence of TETA 4 HCL before) stopped TETA 2 HCL because of cold storage issues (mean duration 42.8 years). The total number of sequences was 57. All of the patients were clinically stable. No difference in efficacy was detected. Both treatments were well tolerated, except for a case of recurrence of lupus erythematosus-like syndrome in the TETA 2HCL group. The major reason for interruption of TETA 4HCL was due to a discontinuation in production of this salt. The reasons for stopping TETA 2HCL were mainly due to adherence issues largely attributed to the cold storage requirement. Conclusions: The two salts of trientine were effective in treating patients with WD. However, interruption of TETA 2HCL was frequent, linked to the cold storage requirement. As adherence to treatment is a key factor in the successful management of WD, physicians need to be even more vigilant in detecting adherence difficulties in patients receiving treatment with TETA 2HCL.

Investigation and management of Wilson's disease: a practical guide from the British Association for the Study of the Liver

Wilson's disease is an autosomal-recessive disorder of copper metabolism with hepatic, neurological, psychiatric, ophthalmological, haematological, renal, and rheumatological manifestations. Making a diagnosis can be challenging given that no single test can confirm or exclude the disease, and diagnostic delays are common. Treatment protocols vary and adverse effects, including paradoxical neurological worsening, can occur. In this Review, we provide a practical guide to the diagnosis of Wilson's disease. We include recommendations on indications for testing, how to interpret results, and when additional investigations are required. We also cover treatment initiation, ideally under the guidance of a specialist centre for Wilson's disease, and the principles behind long-term management. This guidance was developed by a multidisciplinary group of Wilson's disease experts formed through the British Association for the Study of the Liver. The guidance has been endorsed by the British Society of Gastroenterology and approved by the Association of British Neurologists.

Comparison of the Effectiveness and Safety of d-Penicillamine and Zinc Salt Treatment for Symptomatic Wilson Disease: A Systematic Review and Meta‐Analysis

Background: Pharmacological therapy is currently the main treatment method for patients with Wilson disease (WD). We aimed to evaluate the efficacy and safety of the common treatment regimens in these patients.

Methods: We conducted a systemic review and meta-analysis by searching multiple databases for studies from inception to October 2021. Outcomes of interest were the improved rate and safety of d-penicillamine and zinc salts treatment in WD patients. Two independent reviewers performed the study selection and data extraction.

Results: Sixteen studies were included in this meta-analysis. The pooled improved rate for all included symptomatic WD patients was 78.0% (95% CI: 70.8%–85.2%). In symptomatic hepatic WD patients, there is no difference in the treatment efficiency of d-penicillamine and zinc salts (RR: 0.98, 95% CI: 0.86%–1.12%; p = 0.765). In neurological WD patients, the pooled improved rate of those who received d-penicillamine and zinc salts was 56.3% (95% CI: 37.5%–75.1%) and 80.2% (95% CI: 67.2%–93.2%), respectively. The incidence of adverse effects (RR: 2.42, 95% CI: 1.20%–4.88%; p = 0.014) and neurological deterioration (RR: 1.96, 95% CI: 1.31%–2.93%; p = 0.001) in all symptomatic WD patients treated with d-penicillamine was both higher than that of patients treated with zinc salts.

Conclusion: Our analysis suggests that symptomatic WD patients treated with d-penicillamine have higher incidence of adverse effects and neurological deterioration than that of zinc salts. The therapeutic effectiveness of these two regimens does not seem to be significantly different, and these results must be interpreted with caution.

Systematic Review Registration: PROSPERO registration, identifier CRD 42021287126.

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.

Wilson's disease- management and long term outcomes

Wilson's disease (WD) is an autosomal recessive genetic disorder of copper metabolism leading to liver or brain injury due to accumulation of copper. Diagnosis is based on: clinical features, biochemical tests including plasma ceruloplasmin concentration, 24h urinary copper excretion, copper content in the liver, and molecular analysis. Pharmacological therapy comprises chelating agents (penicillamine, trientine) and zinc salts which seem to be very effective. Still, poor compliance is a major problem. Adolescents and patients with psychiatric disorders usually have problems with adherence to treatment. As transition is a vulnerable period transition ''training'' should start before the planned transfer, preferably already in early adolescence in cooperation between adult and pediatric clinics. Response to treatment is assessed based on physical examination, normal liver function tests and monitoring of copper metabolism markers. Liver transplantation has a well-defined role in Wilsonian acute hepatic failure according to the prognostic score. The long-term survival in WD patients seems to be very similar as for the general population if disease is early diagnosed and correctly treated. WD patients with a longer delay from diagnosis to therapy and who present with neurological and psychiatric symptoms have worse quality of life.

Pediatric Wilson's Disease: Phenotypic, Genetic Characterization and Outcome of 182 Children in France

OBJECTIVES

To describe a cohort of Wilson disease (WD) pediatric cases, and to point out the diagnostic particularities of this age group and the long-term outcome.

METHODS

Clinical data of 182 pediatric patients included in the French WD national registry from 01/03/1995 to 01/06/2019 were gathered.

RESULTS

Diagnosis of WD was made at a mean age of 10.7 ± 4.2 years (range 1-18 years). At diagnosis, 154 patients (84.6%) had hepatic manifestations, 19 (10.4%) had neurological manifestations, and 9 patients (4.9%) were asymptomatic. The p.His1069Gln mutation was the most frequently encountered (14% of patients).Neurological patients were diagnosed at least 1 year after they presented their first symptoms. At diagnosis, the median urinary copper excretion (UCE) was 4.2 μmol/24 hours (0.2-253). The first-line treatment was d-penicillamine (DP) for 131 (72%) patients, zinc salts for 24 (13%) patients, and Trientine for 17 (9%) patients. Liver transplantation was performed in 39 (21.4%) patients, for hepatic indications in 33 of 39 patients or for neurological deterioration in 6 of 39 patients, mean Unified Wilson's Disease Rating Scale of the latter went from 90 ± 23.1 before liver transplantation (LT) to 26.8 ± 14.1 (P < 0.01) after a mean follow-up of 4.3 ± 2.5 years. Overall survival rate at 20 years of follow-up was 98%, patient and transplant-free combined survival was 84% at 20 years.

CONCLUSION

Diagnosis of WD can be challenging in children, particularly at the early stages of liver disease and in case of neurological presentation; hence the support of clinical scores and genetic testing is essential. Diagnosis at early stages and proper treatment ensure excellent outcomes, subject to good long-term treatment compliance. LT is a valid option for end-stage liver disease not responding to treatment and can be discussed for selected cases of neurological deterioration.

Combined sodium Dimercaptopropanesulfonate and zinc versus D-penicillamine as first-line therapy for neurological Wilson's disease

BACKGROUND

Even though recent research has achieved significant advancement in the development of therapeutic approaches for Wilson's diseases (WD), the current treatment options available for WD are still limited, especially for WD patients with neurological symptoms. This study is intended to compare the therapeutic approaches for WD patients with neurological symptoms receiving either combined sodium 2, 3-dimercapto-1-propane sulfonate (DMPS) and zinc treatment or D-penicillamine (DPA) monotherapy as first-line therapy, and identify the more effective therapeutic approach.

METHODS

The case records of 158 patients diagnosed with neurological WD were retrospectively analyzed. These patients treated with intravenous DMPS + Zinc and in combination with oral zinc as a maintenance therapy (Group 1) or DPA alone (Group 2) for 1 year. During the period of treatment, the neurological symptoms of the patients were assessed using the Global Assessment Scale (GAS) and Barthel index. The key hematological and biochemical parameters of the patients (such as the levels of aminotransferase, serum ceruloplasmin, 24-h urine copper excretion), as well as adverse effects were recorded and analyzed.

RESULTS

Ninety-three patients in Group 1, displayed decreased GAS scores and increased Barthel indexes consistently in comparison with the baseline (P < 0.01). Among them, 82 patients (88.2%) exhibited significant neurological improvement after 1 year, while 8 patients (8.6%) experienced neurological deterioration. Among the 65 patients in Group 2, 37 patients (58.5%) exhibited neurological improvements, while 17 patients (26.2%) experienced neurological deterioration after 1-year follow up. Six patients discontinued their treatment midway due to their exacerbating neurological symptoms. A comprehensive comparison of the effectiveness of the two courses of treatment revealed that patients in group 1 demonstrated a higher improvement ratio (P < 0.01) and lower worsening ratio of the neurological symptoms for the patients (P < 0.01) in comparison to the patients in group 2. Meanwhile, renal function, liver enzyme and blood cell counts remained stabilized in group1.

CONCLUSIONS

This study indicates that the combined therapeutic approach of DPMS and zinc may be a preferred first-line therapy in treating the neurological symptoms of WD, in comparison to the treatment with DPA.

Zinc Monotherapy as an Alternative Treatment Option for Decompensated Liver Disease due to Wilson Disease?

Background

Wilson disease is a rare metabolic disorder involving copper metabolism, and patients may present with a variable degree of hepatic, neurologic, and psychiatric manifestations. In the case of hepatic presentation, treatment is usually initiated with potentially toxic copper chelators (D-penicillamine or Trenton). Although zinc is of low toxicity and low cost for treatment of Wilson disease, it has been limited to the adjunctive as a single maintenance drug or for asymptomatic patients. The use of zinc monotherapy in patients suffering from a severe liver disease was not well studied. In our case report, we describe a pediatric patient who presented with liver failure and the use of zinc monotherapy in patients with severe hepatic manifestations. Case presentation. A 15-year-old male patient from Ethiopia presented with generalized body swelling (edema and ascites) with yellowish discoloration of his eyes and easy fatigability. He had hyperbilirubinemia, coagulopathy, hypoalbuminemia, and deranged liver enzymes. He had a Keyser–Fleischer ring visible with the naked eye, which was confirmed by slit-lamp examination. He had very low serum ceruloplasmin (<8 mg/L) and high 24-hour urine copper (150 mcg/dl). In accordance with the scoring system proposed by the 8th International Meeting on Wilson Disease and Menkes Disease, a diagnosis of Wilson disease was made. Zinc monotherapy with low copper diet was initiated for decompensated liver disease due to Wilson disease because of the inaccessibility of chelators (D-penicillamine or Trientine). After months of treatment with zinc, the patient experienced normalization of hepatic synthetic function and resolution of hypoalbuminemia and coagulopathy. The patient had also clinically stabilized (ascites, lower extremity swelling, edema, and jaundice were improved. Currently, the patient is on follow-up almost for the last four years in the gastrointestinal clinic.

Conclusion

Our case shows that zinc has the potential for treatment in improving liver function. Though zinc has its own side effects, it is important and maybe an alternative treatment option in those with limited resources (not able to access chelators). This example hopefully will encourage future investigations and researches on zinc monotherapy for treating symptomatic decompensated hepatic Wilson disease.

Wilson disease in children and adolescents

Wilson disease (WD) is a rare, recessively inherited disorder of copper metabolism mainly affecting liver and brain. In childhood, it is known to have a predominant hepatic phenotype. It is likely that the low awareness for WD-associated neuropsychiatric signs and symptoms in this age group means that neurological Wilson's disease is underdiagnosed in children and young people. Practitioners should be alert for this complication in children with or without liver disease. Management of children with WD requires a dedicated multidisciplinary approach involving hepatologists, geneticists, neurologists and psychiatrists to ensure subtle neuropsychiatric symptoms are identified early and addressed appropriately. This review highlights recent advances in hepatic and neuropsychiatric symptoms of WD in childhood, specific diagnostic tools and pitfalls and summarises existing and potential future treatment options.

Management of Wilson Disease Diagnosed in Infancy: An Appraisal of Available Experience to Generate Discussion

Increased access to molecular genetic testing is changing the demographics for diagnosing inherited disorders and imposing new challenges for medical management. Wilson disease (WD), typically diagnosed in older children and adults, can now be detected in utero and in infants (children younger than 24 months, including neonates) via genetic testing. An evidence-based approach to management of these neonates and extremely young children, who are typically asymptomatic, has been hampered by lack of clinical experience. We present a case of an infantile diagnosis of WD, review available experience, and discuss current trends in antenatal genetic testing of parents and fetus that may lead to a very early diagnosis of WD. Based on physiological and nutritional considerations, we propose an algorithmic approach to management of infantile WD as a starting point for further discussion. Future collaboration amongst specialists is essential to identify evidence-based approaches and best practice for managing treatment of infants with genetically diagnosed WD.

Zinc Maintenance Therapy for Wilson Disease: A Comparison Between Zinc Acetate and Alternative Zinc Preparations

We evaluate Wilson disease (WD) treatment with zinc acetate (U.S. Food and Drug Administration approved) and alternative zinc salts. Studies examining zinc therapy in WD are few, and data on alternative zinc salts are limited. We describe one of the largest recent studies of zinc therapy in WD. First, we conducted a single‐center retrospective review of 59 patients with WD (age 6‐88 years, 32 female patients) treated with zinc (50‐150 mg) for 0.8 to 52 years (median, 26 years); most were on prior chelation therapy (n = 39). Second, we developed a survey to explore patients' zinc therapy experience. Primary endpoints were alamine aminotransferase (ALT) and urine copper excretion (µg/24 hours). Urine copper was categorized as low <25 μg (possible overtreatment), target 25‐100 μg, or elevated >100 μg (possible noncompliance or treatment failure). The target range was reached in 81% of patients on zinc acetate, 73% on zinc gluconate, and 57% on alternative zinc. Low urine copper was not associated with a high ALT. ALT was normal in 77% of patients with target urine copper but only in 16% with urine copper >100 µg. ALT elevations were not significantly different between zinc salts (Kruskal‐Wallis, P = 0.26). Our survey demonstrated the mean age of starting zinc was 26.8 years (3.5‐65 years); most were treated with zinc acetate (45%) and zinc gluconate (42%). Before zinc treatment, 45% of patients were symptomatic; the majority of patients (80%) were asymptomatic on zinc. Gastrointestinal side effects were the predominant reason for changing zinc salts (38%), but most reported no side effects on current zinc therapy (67%). Conclusion: Effective treatment with zinc is possible in many patients with WD. The potential for treatment failure suggests close monitoring and consideration of alternative treatments are paramount for those without both a normal serum ALT and appropriate urine copper excretion.

We describe one of the largest recent studies of Zn therapy in WD and include data on alternative Zn salts which is lacking thus far. In clinical practice, due to issues of intolerance and increased cost of WD medications, many patients have gravitated towards alternative Zn salts, some purchasing non‐prescription Zn over‐the‐counter. An understanding of the potential utility of different Zn preparations and required monitoring will provide benefit in expanding and optimizing treatment options for patients with WD.

Liver pathology in Wilson's disease: From copper overload to cirrhosis

Wilson's disease (WD) is a genetic metabolic disease strictly associated with liver cirrhosis. In this review, the genetic bases of the disease are discussed, with emphasis on the role of ATP7B (the Wilson disease protein) dysfunction as a determinant factor of systemic copper overload. Regarding the different multiple mutations described in WD patients, the peculiarity of Sardinian population is highlighted, Sardinians carrying a rare deletion in the promoter (5' UTR) of the WD gene. The role of epigenetic changes in the clinical presentation and evolution of liver disease in WD patients is also discussed, nutrition probably representing a relevantly risk factor in WD patients. The role of transmission electron microscopy in the diagnosis of WD-related liver disease is underlined. Mitochondrial changes, increased peroxisomes fat droplets, lipolysosomes and intranuclear glycogen inclusions are reported as the most frequent ultrastructural changes in the liver of WD carriers. The role of histochemical stains for copper is analyzed, and the Timm's method is suggested as the most sensitive one for revealing hepatic copper overload in all stage of WD. The marked variability of the histological liver changes occurring in WD is underlined simple steatosis may represent the only pathological changes, frequently associated with glycogenated nuclei. Mallory-Denk bodies lipogranulomas alcoholic and non-alcoholic fatty liver disease ending with bridging fibrosis and cirrhosis. Finally, the reversal of fibrosis as a possible therapeutic objective in WD is discussed.

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.

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's Disease in Children: A Position Paper by the Hepatology Committee of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

Clinical presentations of Wilson's disease (WD) in childhood ranges from asymptomatic liver disease to cirrhosis or acute liver failure, whereas neurological and psychiatric symptoms are rare. The basic diagnostic approach includes serum ceruloplasmin and 24-hour urinary copper excretion. Final diagnosis of WD can be established using a diagnostic scoring system based on symptoms, biochemical tests assessing copper metabolism, and molecular analysis of mutations in the ATP7B gene. Pharmacological treatment is life-long and aims at removal of copper excess by chelating agents as D-penicillamine, trientine, or inhibition of intestinal copper absorption with zinc salts. Acute liver failure often requires liver transplantation. This publication aims to provide recommendations for diagnosis, treatment, and follow-up of WD in children.

METHODS

Questions addressing the diagnosis, treatment, and follow-up of WD in children were formulated by a core group of ESPGHAN members. A systematic literature search on WD using MEDLINE, EMBASE, Cochrane Database from 1990 to 2016 was performed focusing on prospective and retrospective studies in children. Quality of evidence was assessed according to the GRADE system. Expert opinion supported recommendations where the evidence was regarded as weak. The ESPGHAN core group and ESPGHAN Hepatology Committee members voted on each recommendation, using the nominal voting technique.

Wilson disease in children

Wilson disease (WD) is an inherited disorder mainly of hepatocellular copper disposition, due to dysfunction of the Wilson ATPase, a P_1B-ATPase encoded by the gene ATP7B. In children, as in older age brackets, clinical disease is highly diverse. Although hepatic disease is the common presentation in children/adolescents, neurologic, psychiatric, and hematologic clinical presentations do occur. Very young children may have clinically evident liver disease due to WD. Early diagnosis, preferably when the child/adolescent is asymptomatic, is most likely to result in near-normal longevity with generally good health so long as the patient tolerates effective medication, is adherent to the lifelong treatment regimen, and has consistent access to the medication. Apart from a lively index of clinical suspicion on the part of physicians, biochemical tests including liver tests, serum ceruloplasmin, and basal 24-hour urinary copper excretion and genotype determination are key to diagnosis. Oral chelation treatment remains central to medical management, although zinc appears to be an attractive option for the presymptomatic child. Pediatric patients presenting with Wilsonian fulminant hepatic failure must be differentiated from those with decompensated cirrhosis, since the latter may respond to intensive medical interventions and not require liver transplantation. Recently identified WD-mimic disorders reveal important aspects of WD pathogenesis.

Long-term metabolic correction of Wilson's disease in a murine model by gene therapy

BACKGROUND & AIMS

Wilson's disease (WD) is an autosomal recessively inherited copper storage disorder due to mutations in the ATP7B gene that causes hepatic and neurologic symptoms. Current treatments are based on lifelong copper chelating drugs and zinc salts, which may cause side effects and do not restore normal copper metabolism. In this work we assessed the efficacy of gene therapy to treat this condition.

METHODS

We transduced the liver of the Atp7b(-/-) WD mouse model with an adeno-associated vector serotype 8 (AAV8) encoding the human ATP7B cDNA placed under the control of the liver-specific α1-antitrypsin promoter (AAV8-AAT-ATP7B). After vector administration we carried out periodic evaluation of parameters associated with copper metabolism and disease progression. The animals were sacrificed 6months after treatment to analyze copper storage and hepatic histology.

RESULTS

We observed a dose-dependent therapeutic effect of AAV8-AAT-ATP7B manifested by the reduction of serum transaminases and urinary copper excretion, normalization of serum holoceruloplasmin, and restoration of physiological biliary copper excretion in response to copper overload. The liver of treated animals showed normalization of copper content and absence of histological alterations.

CONCLUSIONS

Our data demonstrate that AAV8-AAT-ATP7B-mediated gene therapy provides long-term correction of copper metabolism in a clinically relevant animal model of WD providing support for future translational studies.