Zinc monotherapy for young children with presymptomatic Wilson disease: A multicenter study in Japan.

BACKGROUND AND AIM

Few studies of zinc monotherapy for presymptomatic Wilson disease have focused on young children. We therefore evaluated long-term efficacy and safety of zinc monotherapy for such children and established benchmarks for maintenance therapy.

METHODS

We retrospectively and prospectively examined children under 10 years old with presymptomatic Wilson disease who received zinc monotherapy from time of diagnosis at 12 participating pediatric centers in Japan.

RESULTS

Twenty-four patients met entry criteria. Aspartate aminotransferase and alanine aminotransferase decreased significantly beginning 1 month after initiation of treatment and usually remained under 50 U/L from 1 to 8 years of treatment. Twenty four-hour urinary copper decreased significantly at 6 months and usually remained under 75 μg/day and between 1 and 3 μg/kg/day for the remainder of the study. All patients continued to take zinc, and none became symptomatic. In patients under 6 years old who received 50 mg/day of zinc as an initial dose, aspartate aminotransferase and alanine aminotransferase significantly decreased at 1 month after initiation of treatment, as did γ-glutamyltransferase and 24-h urinary copper at 6 months.

CONCLUSIONS

To our knowledge, this is the first multicenter study of zinc monotherapy for young children with presymptomatic Wilson disease. Such monotherapy proved highly effective and safe. Maintaining normal transaminase values (or values under 50 U/L when normalization is difficult) and 24-h urinary copper excretion between 1 and 3 μg/kg/day and under 75 μg/day is a reasonable goal. An initial dose of 50 mg/day is appropriate for patients under 6 years old.