Serum complement 3 is a potential biomarker for assessing disease activity in Takayasu arteritis

Table 2 The sensitivity and specificity of different biomarkers to distinguish the TA disease activity

Marker	AUC	Cut-off value	Sen	Spe	PLR	NLR	PPV	NPV
ESR*	0.766 (0.698–0.800)	26.5	0.638	0.731	2.371	0.495	0.923	0.780
C3	0.715(0.650–0.781)	1.085	0.699	0.667	2.099	0.451	0.911	0.667
CRP	0.703(0.647–0.760)	10.65	0.507	0.824	2.881	0.598	0.923	0.824
Globin	0.658(0.600–0.716)	29.05	0.543	0.736	2.057	0.621	0.890	0.736
Albumin^#	0.623(0.556–0.690)	40.25	0.667	0.581	1.592	0.573	0.721	0.345
Haemoglobin^#	0.620(0.559–0.681)	120.95	0.642	0.583	1.540	0.614	0.723	0.358
IgG	0.617(0.549–0.685)	13.32	0.503	0.736	1.905	0.675	0.895	0.736
CH50	0.614(0.529–0.699)	60	0.663	0.574	1.556	0.587	0.873	0.574
IL-6	0.610(0.533–0.686)	8.85	0.38	0.817	2.077	0.759	0.776	0.817
IgA	0.592(0.524–0.661)	2.865	0.438	0.743	1.704	0.756	0.881	0.743
PLT	0.566(0.506–0.627)	274.5	0.504	0.663	1.496	0.748	0.860	0.663
Parallel test
ESR + C3	0.683(0.600–0.767)		0.891	0.488	1.740	0.223	0.884	0.615
CRP + C3	0.703(0.623–0.782)		0.851	0.550	1.891	0.271	0.895	0.670
ESR + CRP	0.713(0.638–0.788)		0.822	0.602	2.066	0.296	0.901	0.710
Serial test
ESR + C3	0.758(0.700–0.816)		0.446	0.910	4.956	0.609	0.982	0.964
CRP + C3	0.703(0.639–0.766)		0.354	0.941	6.000	0.687	0.963	0.912
ESR + CRP	0.699(0.631–0.738)		0.323	0.953	6.832	0.710	0.960	0.918

IgG immunoglobin G, CH50 median hemolytic complement, IgA immunoglobin A, PLT platelet, PLR positive likelihood ratio, NLR negative likelihood ratio, PPV positive predication value, NPV negative prediction value, Sen sensitivity, Spe specificity
^*ESR belongs to the Kerr criteria and is used as the control here
^#In the ROC curves, the disease activity status discrimination for albumin and haemoglobin is “0” (i.e. Inactive disease)

ISSN: 1478-6362