Observation on the changes of clinical symptoms, blood and brain copper deposition in Wilson disease patients treated with dimercaptosuccinic acid for 2 years.

Objective: To compare the clinical symptoms, brain copper deposition changes of Meso-2,3-dimercaptosuccinic acid (DMSA) and penicillamine therapy in patients with Wilson disease (WD) within 2 years.

Methods: 68 drug-naive patients with WD were enrolled. 10 WD patients treated with zinc gluconate alone were used as the control group. Neurological symptoms were scored using the modified Young Scale. Liver function tests, copper indices and sensitive weighted imaging (SWI) examination were collected. The values of corrected phase (CP) were collected. WD patients were treated with DPA (group 1) or DMSA (group 2) for two years, and followed up every 2 months.

Results: The ratio of neurological improvement in group 2 was higher than that in group 1 (P = 0.029). Higher rate of neurologic worsening was noticed in patients treated with DPA vs DMSA (P = 0.039). The post-treatment neurological score of DMSA group was lower than that of Zn group (P = 0.037). Hepatic function in 63.3% of patients was stable, while 16.7% was improved, and 20% was deteriorated, after DMSA therapy. Urinary copper levels were lower 1 month (p = 0.032), 4 months (p = 0.041), 12 months (p = 0.037) after initiation of treatment in group 2 than in group 1. At the first year of treatment, the CP values in globus pallidus and substantia nigra in group 2 were higher than those in group 1 (P = 0.034,0.039). At the second year of treatment, the CP values of substantia nigra in group 2 were higher (P = 0.041). Discontinuation was more common in patients on DPA therapy (P = 0 0.032).

Conclusions: DMSA could remove metal from brain tissue faster than DPA. DMSA is effective for neurologic symptoms, while the outcome for hepatic symptoms is not entirely satisfactory. DMSA therapy is better tolerated than DPA.