Table 3.

Prevalence of aPS/PT IgG and IgM antibodies compared to LA, aCL, and aβ2GPI at first sample.

	APS/SLE/others patients (n = 79)
	LA		aCL Ab IgG		aβ2GPI Ab IgG		LA-aCL-aβ2GPI Ab IgG		aCL-aβ2GPI Ab IgG
	Positive	Negative	Positive	Negative	Positive	Negative	Triple positive	Triple negative	Double positive	Double negative
	n = 25	n = 54	n = 22	n = 57	n = 30	n = 49	n = 16	n = 44	n = 5	n = 44
aPS/PT Ab IgG	Kappa: 0.84		Kappa: 0.36		Kappa: 0.22		Kappa: 0.38		Kappa: 0.11 (0 ∈ 95%IC)
Positive	25 (100)	6 (11)	9 (41)	5 (9)	9 (30)	5 (10)	7 (44)	4 (9)	1 (20)	4 (9)
Negative	0 (0)	48 (89)	13 (59)	52 (91)	21 (70)	44 (90)	9 (56)	40 (91)	4 (80)	40 (91)
	LA		aCL Ab IgM		aβ2GPI Ab IgM		LA-aCL-aβ2GPI Ab IgM		aCL-aβ2GPI Ab IgM
	Positive	Negative	Positive	Negative	Positive	Negative	Triple positive	Triple negative	Double positive	Double negative
	n = 25	n = 54	n = 20	n = 59	n = 16	n = 63	n = 7	n = 42	n = 5	n = 42
aPS/PT Ab IgM	Kappa: 0.35		Kappa: 0.33		Kappa: 0.23		Kappa: 0.42		Kappa: 0.26
Positive	20 (80)	21 (39)	17 (85)	24 (41)	13 (81)	28 (44)	7 (100)	12 (29)	4 (80)	12 (29)
Negative	5 (20)	33 (61)	3 (15)	35 (59)	3 (19)	35 (56)	0 (0)	30 (71)	1 (20)	30 (71)

Values of categorical variables are expressed as number and (percentage). Cohen’s kappa interpretation: poor <0.20; weak 0.21–0.40; moderate 0.41–0.60; good 0.61–0.80; very good 0.81–1.00.

APS, anti-phospholipid syndrome; SLE, systemic lupus erythematous; aPS/PT, anti-phosphatidylserine/prothrombin antibodies.