Phosphorylated Alpha-Synuclein in Red Blood Cells as a Potential Diagnostic Biomarker for Multiple System Atrophy: A Pilot Study

Table 5

Statistics for pS-α-syn-RBC in diagnosis and subtyping analyzing of MSA.

Comparison	pS-α-syn-RBC (ng/mg, Mean ± S.D)	AUC (95% CI)	-value	Cut-off (ng/mg)	Sensitivity (%, 95% CI)	Specificity (%, 95% CI)	PPV (%, 95%CI)	NPV (%, 95% CI)	LR (+)†	LR (−)‡
MSA/Control	14.02 ± 4.02/11.89 ± 3.57	0.91 (0.87–0.94)	<0.001	10.90	80.37 (71.58–87.42)	88.64 (83.68–92.51)	81.87 (74.65–87.99)	87.62 (81.43–92.10)	7.07	0.22
MSA-P/MSA-C	13.27 ± 1.91/12.19 ± 3.04	0.65 (0.53–0.78)	=0.025	12.08	57.14 (40.96–72.28)	75.76 (57.74–88.91)	63.87 (49.44–76.23)	70.21 (49.22–86.70)	2.36	0.57

The cur-off values were determined by Youden’s suggested index. †LR (+) = sensitivity/1-specificity. ‡NPV = LR (−) = 1-sensitivity/specificity. Bold: . pS-α-syn-RBC, phosphorylated α-syn in RBC; AUC, area under curve; PPV, positive predictive value; NPV, negative predictive value; LR (+), positive likelihood ratio; LR (−), negative likelihood ratio.