Oral zinc as initial therapy in Wilson's disease: two years of continuous treatment in a 10-year-old child

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.

Zinc Therapy for Wilson Disease in Children in French Pediatric Centers

BACKGROUND AND AIMS

Zinc therapy is considered a good option in Wilson disease (WD), as a first-line treatment in presymptomatic children and a maintenance therapy after the initial chelator therapy. The aim of the study was to determine the practical use of zinc treatment in French pediatric centers.

METHODS

A national survey was conducted in the 6 French centers using zinc acetate to treat WD. Clinical and biological parameters, dosage, and outcome were recorded.

RESULTS

A total of 26 children were reported to be treated with zinc acetate, alone or in association with chelators. Of the 9 children (35%) who received zinc alone as a first-line therapy, 2 were switched to D-penicillamine because of inefficacy and 7 remained on zinc alone, but serum transaminase levels normalized in only 4 of them. Five children (19%) were initially treated with zinc in association with D-penicillamine (n = 4) or Trientine (n = 1) with good efficacy. Among the 12 children (46%) who received zinc as a maintenance therapy after D-penicillamine, no relapse of hepatic cytolysis occurred during a median follow-up of 5.2 years, but 2 of them were switched to Trientine because of zinc-related adverse effects. Epigastric pain was observed in 4 children, and a gastric perforation occurred in 1 child.

CONCLUSIONS

The present study demonstrates poor efficacy of zinc as first-line therapy to control liver disease in half presymptomatic children and a high incidence of related gastrointestinal adverse effects in children with WD.

Neutrophil behavior following exposure to in vivo or in vitro zinc in normal and acutely-inflamed rats: studies on lysozyme secretion, superoxide anion release and platelet adhesion

The mechanism was studied of the anti-inflammatory effect of oral zinc (114 mg/kg/day of elemental metal, given for 14 days) on the development of the carrageenan-induced paw oedema of the rat, and the impact of in vivo treatment on the activity of neutrophils isolated from the blood of inflamed and non-inflamed animals. The effects of the in vitro incubation with the metal on either non-inflamed or inflamed neutrophils coming from zinc-untreated rats were also examined. It was found that the administration of oral zinc inhibited markedly the process of ex vivo adhesion of the cells obtained from the inflamed rats (an observation confirmed by the in vitro experiments). In vitro release of lysozyme and superoxide anion productions were measured: in the absence of zinc, the 30' of pre-incubation carried out before stimulating with PMA did not influence the cell's reactivity of the non-inflamed neutrophils. It was, on the contrary, capable of significantly reducing that of the inflamed ones. As a consequence, it is quite difficult to properly interpret the data obtained studying the activity of the cells exposed to the metal in vitro.

Zinc acetate treatment in Wilson's disease

OBJECTIVE

To briefly review the pathophysiology and diagnosis of Wilson's disease, and to evaluate the pharmacology, pharmacokinetics, clinical utility, adverse effects, dosing regimens, and pharmacoeconomics of zinc acetate therapy in Wilson's disease.

DATA SOURCES

A MEDLINE search (December 1966-December 1996) of the English-language literature using the terms zinc and Wilson's disease was conducted to identify pertinent clinical trials, review articles, and case reports. Additional articles were selected from bibliographies of the reviewed literature.

STUDY SELECTION AND DATA EXTRACTION

Due to the rarity of the disease, all articles were considered for possible inclusion in this review. Single case reports are referenced, but were not selected for evaluation.

DATA SYNTHESIS

Wilson's disease, an inherited disorder of copper metabolism, is fatal if untreated. The chelating drugs penicillamine and trientine have been the mainstay of therapy; however, adverse reactions of chelators often interfere with successful treatment. Recently, zinc acetate was approved in the US for maintenance therapy in patients initially treated with a chelating agent. Although studies evaluating large populations are lacking zinc therapy has demonstrated exceptional safety and efficacy over a period of 40 years. Zinc acetate can be used during pregnancy and for the treatment of presymptomatic patients, although data do not support its use as monotherapy in patients with acute neurologic or hepatic disease.

CONCLUSIONS

Zinc acetate is an effective maintenance therapy for patients with Wilson's disease. Negligible toxicity, compared with that of previously approved treatments, is a major advantage.