Table 1.
Characteristics of patients with PD and disease controls.
Fig 1.
Theophylline levels in sera of the PD and control groups.
Fig 1(A) Scatter plot showing the levels of serum theophylline in the control (n = 33) and PD (n = 31) groups. Bars indicate median values. The levels of theophylline in the PD group were significantly lower than those in the control group (P = 0.0383). Fig 1(B) ROC curve showing serum levels of theophylline to discriminate PD patients from controls. The AUC value was 0.65.
Fig 2.
Serum levels of theophylline in PD patients with and without motor complications.
Scatter plot showing levels of serum theophylline in patients with PD with (n = 6) and without (n = 25) motor complications. The levels of serum theophylline in patients with motor complications were lower than in those without them, although the difference was not significant (p = 0.42).
Fig 3.
Concept of biomarker repurposing.
The process of biomarker development is shown. Biomarker repurposing, the novel application of existing biomarkers for other purposes, enables the skipping of the development of quantification and standardization processes [27, 28].