Celiac disease serology in patients with different pretest probabilities: Is biopsy avoidable?

Table 2 Statistical performance of individual CD serologic tests for high- and low-risk populations at cut-offs provided by the manufacturer and when the cut-off is set for a 100% PPV

Test	% (95% CI)			(%)
	Sensitivity	Specificity	AU ROC	PPV	NPV
High-risk population
IgA a-tTG
(cut-off 20 U/mL)	95.2 (86.7-99.0)	97.9 (92.8-99.7)	0.997 (0.971-0.998)	96.9	96.8
(cut-off 34 U/mL)	93.6 (84.5-98.2)	100.0 (96.3-100.0)	0.968 (0.928-0.989)	100.0	96.0
IgA a-DGP
(cut-off 20 U/mL)	98.4 (91.4-99.7)	92.7 (85.5-97.1)	0.995 (0.968-0.999)	90.0	98.9
(cut-off 77 U/mL)	87.3 (76.5-94.3)	100.0 (96.3-100.0)	0.995 (0.968-0.999)	100.0	92.5
IgG a-DGP
(cut-off 20 U/mL)	95.2 (86.7-99.0)	100.0 (96.2-100.0)	0.989 (0.958-0.998)	100.0	97.0
(cut-off 20 U/mL)
DGP Dual
(cut-off 20 U/mL)	96.8 (89.0-99.5)	99.0 (94.4-99.8)	0.995 (0.967-0.999)	98.4	97.9
(cut-off 22 U/mL)	96.8 (89.0-99.5)	100.0 (96.3-100.0)	0.984 (0.951-0.997)	100.0	98.0
DGP/tTG Screen
(cut-off 20 U/mL)	100.0 (94.3-100.0)	92.8 (85.8-97.1)	0.999 (0.976-1.000)	90.3	100.0
(cut-off 54 U/mL)	98.4 (91.4-99.7)	100.0 (96.3-100)	0.992 (0.963-0.999)	100.0	99.0
IgA AAA
(cut-off 25 U/mL)	87.3 (76.5-94.3)	94.9 (88.5-98.3)	0.968 (0.927-0.989)	91.9	91.8
(cut-off 64 U/mL)	52.4 (39.4-65.0)	100.0 (96.3-100.0)	0.770 (0.697-0.832)	100.0	76.6
Low-risk population
IgA a-tTG
(cut-off 20 U/mL)	76.5 (50.1-93.0)	97.4 (95.6-98.6)	0.921 (0.894-0.942)	50.0	99.2
(cut-off 139 U/mL)	35.3 (14.3-61.6)	100.0 (98.9-100.0)	0.706 (0.665-0.745)	100.0	97.8
IgA a-DGP
(cut-off 20 U/ mL)	82.3 (56.6-96.0)	96.2 (94.1-97.7)	0.932 (0.907-0.952)	42.4	99.4
(cut-off 313 U/mL)	35.3 (14.3-61.6)	100.0 (99.3-100.0)	0.706 (0.655-0.745)	100.0	97.9
IgG a-DGP
(cut-off 20U/mL)	70.6 (44.1-89.6)	99.0 (97.7-99.7)	0.926 (0.900-0.947)	70.6	99.0
(cut-off 109 U/mL)	29.4 (10.4-55.9)	100.0 (99.3-100.0)	0.676 (0.634-0.717)	100.0	97.7
DGP Dual
(cut-off 20 U/ mL)	76.5 (50.1-93.0)	95.8 (93.7-97.4)	0.963 (0.943-0.978)	38.2	99.2
(cut-off 77 U/mL)	47.1 (23.0-72.1)	100.0 (99.3-100.0)	0.735 (0.695-0.773)	100.0	98.2
DGP/tTG Screen
(cut-off 20 U/mL)	82.3 (56.6-96.0)	88.2 (85.1-90.9)	0.972 (0.954-0.984)	19.2	99.3
(cut-off 128 U/mL)	64.7 (38.4-85.7)	100.0 (98.9-100.0)	0.824 (0.788-0.855)	100.0	97.8
IgA AAA
(cut-off 25 U/mL)	52.9 (27.9-77.0)	91.6 (88.8-93.9)	0.835 (0.800-0.866)	17.6	98.3
(cut-off 106 U/mL)	29.4 (10.4-55.9)	100.0 (99.3-100.0)	0.647 (0.604-0.688)	100.0	97.7

The statistical performance of tests if concentrations are above the cutoff. PPV: Positive predictive value; NPV: Negative predictive value; tTG: Tissue transglutaminase; DGP: Deamidated gliadin peptide; AAA: IgA antiactin antibodies; AU ROC: Area under the ROC curve.