Table 1.
Demographics of the subjects and clinical characteristics of the patients with Parkinson’s disease (PD).
Fig 1.
Determination of the optimal HAI concentration for the A-syn 211-FL140 ELISA.
Chemiluminescence signals obtained from serially diluted recombinant A-syn in the presence of various HAI concentrations (0, 5, 16.7 and 50%) with the 211-FL140 ELISA. ELISA performance was not affected by 5% HAI, and was reduced in the presence of 16.7% and 50% HAI.
Fig 2.
Effects of HA on measurements of CSF and plasma A-syn levels using the 211-FL140 ELISA.
Levels of CSF-A-syn (A) and plasma-A-syn (B) were measured using the 211-FL140 ELISA in the absence and presence of 5% HAI. HAI pretreatment slightly increased A-syn signals in the majority of CSF samples (A), while the A-syn signals were remarkably decreased in most of the plasma samples (B). (C) In order to detect HA in plasma samples, the primary antibodies (C211 and FL-140) were separated by blue native-PAGE and immunoblotted with two plasma samples. The plasma sample on the left exhibited high HA activity, while the sample on the right had low HA activity in previous experiments that had determined the effects of HAI on the 211-FL140 ELISA. The plasma with high HA activity clearly reacted with both the 211 and FL-140 antibodies, while the plasma with low HA activity did not react with either.
Fig 3.
Comparison of A-syn levels measured using the 211-FL140 ELISA with HAI pretreatment.
Values of A-syn obtained from individual subjects are plotted. (A) A-syn levels are compared between CSF and plasma in the overall samples. (B, C) The levels of CSF (B) and plasma (C) A-syn are compared between the control and PD groups. Long and short horizontal bars represent mean and standard deviation, respectively. The mean plasma A-syn levels was significantly higher than mean CSF A-syn (A; p = 0.043). The mean CSF and plasma A-syn levels were lower in the PD group compared to the control group (B, C), but a significant difference was only observed in the plasma samples (C; p = 0.034).
Fig 4.
Correlations between Hb and A-syn levels in plasma and CSF.
(A, B) Scatter plots of the levels of Hb versus those of A-syn in plasma measured without (A) or with (B) HAI pretreatment. (C, D) Scatter plots of Hb versus A-syn in CSF measured without (C) or with (D) HAI pretreatment. Closed rectangles and triangles indicate samples from the PD group, open rectangles and triangles are those from the control group. The horizontal axis is shown on a logarithmic scale. There were no significant correlations between the levels of Hb and plasma A-syn without (A; p = 0.86) or with (B; p = 0.39) HAI pretreatment. Significant correlations were not also observed between Hb and CSF A-syn without (C; p = 0.93) or with (D; p = 0.65) HAI pretreatment.
Fig 5.
Correlations between A-syn levels in CSF and plasma samples obtained at the same time.
Scatter plots of A-syn levels in CSF versus plasma in the PD group (A), control group (B), and the combination of PD patients and the controls (C). Closed and open circles indicate samples from the PD and the control groups, respectively. The solid lines indicate regression analyses. There was a significant positive correlation in the PD group (A) (p = 0.005). In the control group (B), no significant correlation was observed (p = 0.50). Dashed lines in (C) indicate the mean values of CSF (29.07 ng/ml) and plasma (31.72 ng/ml) A-syn in the controls, and are plotted to clarify the discrepancy between the PD and control groups with respect to the relationship between CSF and plasma A-syn levels. There was a tendency for patients whose CSF A-syn levels were lower than 29.07 ng/ml to exhibit plasma A-syn levels less than 31.72 ng/ml in the PD group (closed circles, Fig 5C); however, no such a tendency was observed in the control group (open circles, Fig 5C).