Table 2.

Specificity and Sensitivity analyses for RBD antigens against IgA, IgG, and IgM in symptomatic and asymptomatic patients.

Isotype	Cutoff	Days since PCR+	Symptomatic Patients			Asymptomatic patients
			AUC (95% CI)	Sensitivity (%)	Specificity (%)	AUC (95% CI)	Sensitivity (%)	Specificity (%)
IgG	>19	1	0.85 (080−0.90)	64	100	0.64 (0.55−0.74)	21	100
		7	0.98 (0.96–1.00)	96	100	0.65 (0.57 – 0.73)	22	100
		14	0.99 (0.96–1.00)	95	100	0.65 (0.560 0.72)	29	100
		30	1.00 (1.00 – 1.00)	100	100	0.72 (0.65 – 0.80)	45	100
IgA	>19	1	0.87 (0.66 – 0.78)	36	100	0.55 (0.49 – 0.60)	7	100
		7	0.92 (0.88 – 0.96)	79	100	0.62 (0.55 – 0.69)	19	100
		14	0.92 (0.87 – 0.98)	83	100	0.59 (0.52 – 0.67)	20	100
		30	0.85 (0.80 – 0.91)	58	100	0.62 (0.56 – 0.68)	19	100
IgM	>16	1	0.78 (0.72 – 0.84)	51	100	0.60 (0.51 – 0.69)	21	100
		7	0.86 (0.81 – 0.91)	67	100	0.60 (0.52 0 0.67)	24	100
		14	0.93 (0.88 – 0.98)	72	100	0.61 (0.53 – 0.70)	22	100
		30	0.72 (0.66−0.79)	38	100	0.64 (0.57 – 0.71)	26	100