Table 2. Area under the ROC curve of sLC ratio, β2-MG, LDH and Ig.

Clinical indicators	AUC	Standard error	95% confidence interval (AUC)	Optimal cut-off value	Sensitivity (%)	Specificity (%)	P
sLC ratio	0.875	0.0337	0.832–0.910	>3.2121	81.16	94.87	<0.0001*
β 2 -MG	0.843	0.0248	0.797–0.882	>1.95mg/L	91.3	68.8	<0.0001*
LDH	0.547	0.0416	0.489–0.604	>220U/L	42.03	71.79	0.2627
Ig	0.723	0.0442	0.669–0.773	>46.4g/L	56.52	92.31	<0.0001*

* represents P<0.05, with statistical difference.