Clinical utility of quantitative multi-antibody Polycheck immunoassays in the diagnosis of coeliac disease

Table 2 Statistical sensitivity and specificity of Polycheck Celiac IgA and IgG tests for single antibody and for selected multi-antibody combinations

Specific coeliac antibody	Sensitivity %	Specificity %	PPV %	NPV %	AU ROC	LR+2	LR-
Single antibody positivity
Anti-tTG-IgA1	97.7%	100.0%	100.0%	98.0%	98.9%	-	0.023
Anti-tTG-IgG	48.0%	98.0%	96.0%	65.3%	73.0%	24.000	0.531
Anti-DPG-IgA1	34.1%	98.0%	93.8%	62.8%	68.1%	17.045	0.673
Anti-DPG-IgG	100.0%	96.0%	96.2%	100.0%	98.0%	25.000	0.000
Combination of two or more positive antibodies
Anti-tTG-IgA/-IgG + anti-DGP-IgG/-IgA	98.0%	100.0%	100.0%	98.0%	99.0%	-	0.020

¹Calculations after excluding patients with selective IgA deficiency;

²For strategies, where specificity of a test/combination was 100%, the likehood ratio for a positive result could not be calculated. PPV: Positive predictive value; NPV: Negative predictive value; AU ROC: Area under a receiving operator characteristic curve; LR+: Likehood ratio for a positive result; LR-: Likehood ratio for a negative result.