The Study Of β-amyloid Protein 1-42, Cystatin C, Uric Acid And ¹⁸F-FDG Cerebral Metabolism Pet In Patients With Parkinson’s Disease

Objective: To investigate the levels of serum β-amyloid protein 1-42(Aβ1-42),Cystatin C(Cys C), Uric acid(UA) and the imaging characteristics of 18F-FDG PET in patients with PD. Research their relationship with Parkinson’s disease(PD). Methods:Serum samples were tested in Aβ1-42, Cys C and UA, which were collected from 108 cases those were cofirmed sporadic parkinson disease and 108 normal controls. Receiver operating characteristic(ROC) curve was used to detect the area under the curve(AUC),95%CI and sensitivity and spcificity of Aβ1-42, Cys C and UA in PD diagnosis. Selected29 patients with PD, including 19 patients with early PD(H-Y﹤3) and 10 with advanced PD(H-Y ≥ 3), and 29 nomal controls were recruited to perform resting-state brain18F-FDG PET imaging. Statistical Parametric Mapping(SPM) was used to investgaing metabolic rate of glucose in the subregions of the brain, and then calculated the relatively different brain regions between the groups. Results:(1) Serum Aβ1-42 and UA levels were lower in PD patients than controls, while Cys C level in patients was higher than controls(P﹤0.05).(2) ROC curve analysis showed that AUC of Aβ1-42 was 0.644(95%CI: 0.570~0.718, P﹤0.05). Diagnostic sensitivity and specificity were 52.8%, 74.1%respectively, and the critical value of serum Aβ1-42 level was 0.912 ?g/L; AUC of UA was 0.633(95% CI:0.557~0.708, P﹤0.05). Diagnostic sensitivity and specificity were65.7%, 64.8%respectively, and the critical value of serum UA level was 281 ?mol/L.(3)The level of serum Aβ1-42 in Han PD patients decreased than Uygur PD patients(P﹤0.05); The level of serum UA in male PD patients increased than female PD patients(P﹤0.05).(4) Serum Cys C level was higer in early and advanced PD groups than control group, especially the level in advanced PD group is much higher than the early PD(P﹤0.05).(5) Serum levels of Aβ1-42 and UA had negative correlation with H-Y grading,while the levels of Cys C had positive correlation(P ﹤0.05). Serum levels of UA had negative correlation with the total socores of UPDRS and scores of UPDRSⅢ(P﹤0.05).(6) Compared with control, hypometabolism were observed in superior frontal gyrus,inferior parietal gyrus, caudate, thalamus(medial dorsal nucleus) and cerebellum(posterior lobe); hypermetabolism were found in putamen, thalamus(ventral lateral nucleus), hippocampus, pons and cerebellar(anterior lobe) with PD(P ﹤ 0.01).(7)Compared with early PD, in those with advanced PD, hypometabolism were observed in frontal gyrus and parietal gyrus, hypermetabolism were observed in hippocampus /parahippocampus, pons and cerebellum(anterior lobe)(P ﹤ 0.01). Conclusions:(1)Serum levels of Aβ1-42 and UA may contribute to the diagnosis of PD, while Cys C may participate during the progress of PD and may helping in judging the severity state of PD.(2) The glucose metabolism in brain of patients with PD signigicantly different from normal controls, and the abnormal metabolism aggravated with the severity of the disease.It may can evaluate the severity of the condition in patients with PD, however, it seems need more studies.