Long-Term Zinc Therapy Highly Effective in Children With Wilson Disease

BOSTON, MA—Long-term zinc monotherapy in young children with asymptomatic Wilson disease was “highly effective and safe,” according to research presented at The Liver Meeting® 2016. 

“A reasonable goal in treating young children with asymptomatic Wilson disease using zinc appears to be maintaining both AST/ALT under 50 U/L and 24-hour urinary copper excretion between 1 and 3μg/kg/day” and under 75μg per day, said Tatsuki Mizuochi, MD, PhD, of the Department of Pediatrics and Child Health, Kurume University School of Medicine, in Kurume, Japan.

Current guidelines from AASLD and EASL recommend zinc monotherapy for asymptomatic patients with Wilson disease but there are few available data on zinc monotherapy for young children with asymptomatic Wilson disease. 

Researchers from Kurume University School of Medicine, in Kurume, Japan, therefore sought to assess the long-term efficacy and safety of zinc monotherapy for pediatric patients aged <10 years with asymptomatic Wilson Disease in Japanese pediatric centers, and to identify benchmarks for maintenance therapy.

The team examined 21 children aged 1–9 years (median age, 6 years) with Wilson disease and no sequelae (jaundice, hepatomegaly, or neurologic abnormalities). They monitored serum AST and ALT, non-ceruloplasmin-bound copper, and 24-hour urinary copper for up to 7 years. Abdominal ultrasonography was performed and monitored clinical manifestations of Wilson disease, drug compliance, and zinc-related adverse events like iron deficiency anemia or pancytopenia.

Children aged ≤5 years were prescribed zinc acetate 25mg twice daily; those aged ≥5 years was prescribed 25mg three times daily. The dosage was increased if patients had AST/ALT >50–70 U/L and were lowered if they experienced adverse effects. 

At baseline, AST/ALT levels were 148±118/ 234±151 U/L and 24-hr urinary copper was 124±54µg/day, respectively. Zinc therapy was continued in all patients with no evidence of zinc toxicity; no patients became clinically symptomatic. 

AST/ALT dropped significantly to 54±30/77±49 U/L (P<0.001) at 1 month after treatment initiation; it was “mostly maintained” at <50 U/L for 1–7 years, Dr. Mizuochi reported. The 24-hr urinary coper also was significantly reduced to 49±21µg/day at 6 months after treatment initiation (P<0.001) and was mostly maintained under 75µg/day and between 1–3µg/kg/day for the rest of the study. 

“A reasonable goal in treating young children with asymptomatic Wilson disease using zinc appears to be maintaining both AST/ALT <50 U/Land 24-hr urinary copper excretion between 1–3µg/kg/day (and <75µg/day),” concluded Dr. Mizuochi.