Accuracy of Helicobacter pylori serology in two peptic ulcer populations and in healthy controls

Table 1 Sensitivity, specificity and likelihood ratio of positive test (LR+) of C14-UBT and IgG and IgA antibodies against H pylori at cut-off values 300 and 500 in vagotomized (vag) or medically (med) treated peptic ulcer patients (med) and in community controls (con)

	Sensitivity (95% CI)			Specificity (95% CI)			LR+ (95% CI)
	vag	med	con	vag	med	con	vag	med	con
Method of detection
C14-UBT	94 (85-99)	92 (81-98)	96 (87-100)	85 (62-97)	80 (56-94)	90 (73-98)	6.3 (2.4-31.5)	4.6 (1.7-17.6)	9.3 (3.0-46.6)
Serology IgG300	95 (86-99)	98 (90-100)	93 (83-98)	41 (21-64)	50 (28-72)	68 (49-83)	1.6 (0.9-3.2)	2.0 (1.0-4.2)	2.9 (1.5-6.4)
Serology IgG500	87 (76-94)	90 (79-97)	83 (70-91)	55 (32-76)	50 (28-72)	71 (52-86)	1.9 (1.0-4.2)	1.8 (0.9-3.9)	2.8 (1.4-6.6)
Serology IgG/IgA1	95 (86-99)	98 (90-100)	93 (83-98)	32 (14-55)	50 (28-72)	58 (39-76)	1.4 (0.8-2.7)	2.0 (1.0-4.2)	2.2 (1.2-4.4)

H pylori infection detected by a positive histology and/or by a positive culture was defined as reference standard.

¹Serology IgG/IgA: IgG ≥ 300 and/or IgA ≥ 500.

Table 2 H pylori status by histology and inflammatory activity in the gastric angulus (anginflam) in different combinations with culture growth, related to level of IgG antibodies against H pylori in each category

	n	Range	Mean (95% CI)	Median
IgG when histologyHP neg and growth neg	66	100-12800	700 (290-1120)	200
IgG when histologyHP pos and growth neg	9	100-18000	4960 (530-9390)	4000
IgG when histologyHP pos and growth pos	143	100-20000	3480 (2740-4220)	1600
IgG when histologyHP neg and growth pos	12	200-7000	2660 (1270-4050)	2250
IgG when anginflam neg and growth neg	60	100-18000	690 (90-1290)	200
IgG when anginflam pos and growth neg	8	300-9000	3830 (1420-6240)	3750
IgG when anginflam pos and growth pos	126	100-20000	3500 (2700-4300)	1650
IgG when anginflam neg and growth pos	19	100-13000	2840 (960-4720)	1200