Journal of Immunology Research

Research Article

Evaluation of an Automated Screening Assay, Compared to Indirect Immunofluorescence, an Extractable Nuclear Antigen Assay, and a Line Immunoassay in a Large Cohort of Asian Patients with Antinuclear Antibody-Associated Rheumatoid Diseases: A Multicenter Retrospective Study

Table 2

Overall agreements among the four autoantibody assays, according to the AARD groups.


Group ()	Assays	CTD screen, cutoff ratio 0.7			CTD screen, cutoff ratio 1.0			HEp-2 IIF			EliA ENA			LIA
Group ()	Assays	Concordance (%)	Kappa	McNemar	Concordance (%)	Kappa	McNemar	Concordance (%)	Kappa	McNemar	Concordance (%)	Kappa	McNemar	Concordance (%)	Kappa	McNemar

Total AARD ()	CTD screen, cutoff ratio 0.7	—	—	—	98.2	0.94 (0.86–1.02)	0.5000	78.6	0.41 (0.22–0.60)	0.0066	89.3	0.70 (0.54–0.85)	0.0005	81.3	0.32 (0.09–0.55)	1.0000
	CTD screen, cutoff ratio 1.0	98.2	0.94 (0.86–1.02)	0.5000	—	—	—	80.4	0.47 (0.29–0.65)	0.0169	89.3	0.70 (0.55–0.86)	0.0063	79.5	0.29 (0.07–0.51)	0.6776
	HEp-2 IIF	78.6	0.41 (0.22–0.60)	0.0066	80.4	0.47 (0.29–0.65)	0.0169	—	—	—	71.4	0.30 (0.11–0.49)	0.8601	74.1	0.28 (0.09–0.47)	0.0081
	EliA ENA	89.3	0.70 (0.54–0.85)	0.0005	89.3	0.70 (0.55–0.86)	0.0063	71.4	0.30 (0.11–0.49)	0.8601	—	—	—	75.9	0.31 (0.11–0.50)	0.0192
	LIA	81.3	0.32 (0.09–0.55)	1.0000	79.5	0.29 (0.07–0.51)	0.6776	74.1	0.28 (0.09–0.47)	0.0081	75.9	0.31 (0.11–0.50)	0.0192	—	—	—
SLE ()	CTD screen, cutoff ratio 0.7	—	—	—	98.5	0.94 (0.82–1.06)	1.0000	83.6	0.47 (0.21–0.73)	0.0654	89.6	0.66 (0.44–0.88)	0.0156	82.1	0.23 (−0.08 to 0.54)	1.0000
	CTD screen, cutoff ratio 1.0	98.5	0.94 (0.82–1.06)	1.0000	—	—	—	85.1	0.53 (0.28–0.78)	0.1094	91.0	0.72 (0.51–0.92)	0.0313	80.6	0.20 (−0.10 to 0.50)	1.0000
	HEp-2 IIF	83.6	0.47 (0.21–0.73)	0.0654	85.1	0.53 (0.28–0.78)	0.1094	—	—	—	76.1	0.34 (0.08–0.60)	1.0000	77.6	0.28 (0.01–0.54)	0.1185
	EliA ENA	89.6	0.66 (0.44–0.88)	0.0156	91.0	0.72 (0.51–0.92)	0.0313	76.1	0.34 (0.08–0.60)	1.0000	—	—	—	77.6	0.28 (0.01–0.54)	0.1185
	LIA	82.1	0.23 (−0.08 to 0.54)	1.0000	80.6	0.20 (−0.10 to 0.50)	1.0000	77.6	0.28 (0.01–0.54)	0.1185	77.6	0.28 (0.01–0.54)	0.1185	—	—	—
SSc ()	CTD screen, cutoff ratio 0.7	—	—	—	100.0	1.00 (1.00-1.00)	1.0000	81.0	0.60 (0.24–0.95)	1.0000	81.0	0.63 (0.33–0.93)	0.1250	76.2	0.48 (0.09–0.87)	1.0000
	CTD screen, cutoff ratio 1.0	100.0	1.00 (1.00-1.00)	1.0000	—	—	—	81.0	0.60 (0.24–0.95)	1.0000	81.0	0.63 (0.33–0.93)	0.1250	76.2	0.48 (0.09–0.87)	1.0000
	HEp-2 IIF	81.0	0.60 (0.24–0.95)	1.0000	81.0	0.60 (0.24–0.95)	1.0000	—	—	—	71.4	0.45 (0.10–0.80)	0.2188	76.2	0.48 (0.09–0.87)	1.0000
	EliA ENA	81.0	0.63 (0.33–0.93)	0.1250	81.0	0.63 (0.33–0.93)	0.1250	71.4	0.45 (0.10–0.80)	0.2188	—	—	—	66.7	0.36 (0.02–0.71)	0.1250
	LIA	76.2	0.48 (0.09–0.87)	1.0000	76.2	0.48 (0.09–0.87)	1.0000	76.2	0.48 (0.09–0.87)	1.0000	66.7	0.36 (0.02–0.71)	0.1250	—	—	—
SS ()	CTD screen, cutoff ratio 0.7	—	—	—	94.7	0.77 (0.35–1.20)	1.0000	57.9	0.04 (−0.28 to 0.36)	0.0703	100.0	1.00 (1.00-1.00)	1.0000	84.2	−0.08 (−0.18 to 0.03)	1.0000
	CTD screen, cutoff ratio 1.0	94.7	0.77 (0.35–1.20)	1.0000	—	—	—	63.2	0.17 (−0.20 to 0.55)	0.1250	94.7	0.77 (0.35–1.20)	1.0000	78.9	−0.09 (−0.22 to 0.05)	0.6250
	HEp-2 IIF	57.9	0.04 (−0.28 to 0.36)	0.0703	63.2	0.17 (−0.20 to 0.55)	0.1250	—	—	—	57.9	0.04 (−0.28 to 0.36)	0.0703	63.2	0.14 (−0.12 to 0.40)	0.0156
	EliA ENA	100.0	1.00 (1.00-1.00)	1.0000	94.7	0.77 (0.35–1.20)	1.0000	57.9	0.04 (−0.28 to 0.36)	0.0703	—	—	—	84.2	−0.08 (−0.18 to 0.03)	1.0000
	LIA	84.2	−0.08 (−0.18 to 0.03)	1.0000	78.9	−0.09 (−0.22 to 0.05)	0.6250	63.2	0.14 (−0.12 to 0.40)	0.0156	84.2	−0.08 (−0.18 to 0.03)	1.0000	—	—	—
MCT ()	CTD screen, cutoff ratio 0.7	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
	CTD screen, cutoff ratio 1.0	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
	HEp-2 IIF	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
	EliA ENA	—	—	—	—	—	—	60	−0.25 (−0.59 to 0.09)	1.0000	—	—	—	—	—	—
	LIA	—	—	—	—	—	—	60	−0.25 (−0.59 to 0.09)	1.0000	60	−0.25 (−0.59 to 0.09)	1.0000	—	—	—
Total ()	CTD screen, cutoff ratio 0.7	—	—	—	97.9	0.92 (0.89–0.95)	<0.0001	85.6	0.48 (0.41–0.55)	0.2698	97.6	0.91 (0.88–0.94)	0.0003	85.7	0.54 (0.48–0.60)	0.0011
	CTD screen, cutoff ratio 1.0	97.9	0.92 (0.89–0.95)	<0.0001	—	—	—	87.4	0.52 (0.45–0.59)	0.5543	96.4	0.86 (0.82–0.90)	—	86.5	0.55 (0.48–0.61)	<0.0001
	HEp-2 IIF	85.6	0.48 (0.41–0.55)	0.2698	87.4	0.52 (0.45–0.59)	0.5543	—	—	—	85.3	0.45 (0.38–0.52)	0.8149	83.4	0.45 (0.39–0.52)	<0.0001
	EliA ENA	97.6	0.91 (0.88–0.94)	0.0003	96.4	0.86 (0.82–0.90)	0.6358	85.3	0.45 (0.38–0.52)	0.8149	—	—	—	85.7	0.53 (0.46–0.59)	<0.0001
	LIA	85.7	0.54 (0.48–0.60)	0.0011	86.5	0.55 (0.48–0.61)	<0.0001	83.4	0.45 (0.39–0.52)	<0.0001	85.7	0.53 (0.46–0.59)	<0.0001	—	—	—

IIF: indirect immunofluorescence; ENA: extractable nuclear antigen; LIA: line immunoassay; AARD: antinuclear antibody-associated rheumatoid disease; SLE: systemic lupus erythematosus; SSc: systemic sclerosis; SS: Sjögren’s syndrome; MCTD: mixed connective tissue disease; NS: not stated because of impractical calculation. Kappa coefficient between the assays are shown (95% confidence interval). values of the McNemar tests.