TABLE 2.

Diagnostic accuracy of VacA antigens at predetermined cutoff values

VacA antigen and analysis	Sample characteristics	AUCc	Cutoff valued	% Sensitivity	% Specificity
Unmodifieda
P44M1	32 m1 colonized, 142 not m1 colonized	0.870	0.8	75	89
			1.0	69	92
P48M2	65 m2 colonized, 109 not m2 colonized	0.598	0.6	35	73
			0.8	26	86
P55M2	65 m2 colonized, 109 not m2 colonized	0.631	0.6	74	47
			0.8	54	70
Modifiedb
P48M2-mod	59 m2 colonized, 82 not m2 colonized	0.670	0.6	31	85
			0.8	22	96
P55M2-mod	59 m2 colonized, 82 not m2 colonized	0.701	0.6	72	59
			0.8	52	82

^aIncludes all serum samples from 174 patients.

^bExcludes samples with a positive serologic response to P44M1 antigen; samples were from 141 patients.

^cAUC in ROC analysis (19).

^dThe cutoff value is the ratio of the OD value to the seropositivity cutoff value. Values greater than or equal to the cutoff are considered to indicate immune responses to the specific antigen.