Serum ceruloplasmin and striatal dopamine transporter density in Parkinson disease: Comparison with ¹²³I-FP-CIT spect

Purpose In patients with Parkinson disease (PD), decreased serum ceruloplasmin levels have been observed. This study investigated a correlation between serum ceruloplasmin - along with its related serum markers -and striatal presynaptic dopaminergic denervation measured with 123 I-FP-CIT SPECT. Methods We analyzed a total of 141 de novo patients divided into 2 groups: the PD group (107 patients with PD) and the disease control group (34 patients with vascular pseudoparkinsonism, essential tremor, or drug-induced parkinsonism). Serum ceruloplasmin and related serum markers, such as copper, iron, total iron-binding capacity, and ferritin, were measured. Specific binding ratios of the striatum, caudate nucleus, putamen, and posterior putamen were obtained by 123 I-FP-CIT SPECT. Results There was no difference in the serum markers, except for ceruloplasmin, between the 2 groups. Ceruloplasmin level was significantly lower in PD patients with longer symptom duration (>2 years) than in the disease control group (21.4 ± 3.4 vs 24.0 ± 3.8, P = 0.03). Serum ceruloplasmin had a significant correlation with specific binding ratios of the striatum, caudate nucleus, and putamen in a subgroup with longer symptom duration (P = 0.01, P = 0.02, P = 0.02, respectively, for the subgroup with symptom duration >1 year, and P < 0.01, P < 0.01, P = 0.04, respectively, for the subgroup with symptom duration >2 years). Conclusions Decrease in serum ceruloplasmin had a positive correlation with a decrease in dopamine transporter density in PD patients with symptom duration of more than 1 year.