Diagnostic accuracy of a novel enzyme-linked immunoassay for the detection of IgG and IgG4 against Strongyloides stercoralis based on the recombinant antigens NIE/SsIR

Table 5 Cut-off values, sensitivity and specificity of the index InBios ELISA tests using the primary (fecal test) and secondary (CRS) reference standards

Reference standard	Indeterminate cases	Test	Cut-off value	Sensitivity (95% CI)	P^a	Specificity (95% CI)	P^a
Primary—fecal test	n/a	IgG	0.714	0.93 (0.88–0.97)	< 0.0001	0.91 (0.88–0.95)	0.0325
Primary—fecal test	n/a	IgG4	0.609	0.81 (0.74–0.87)	< 0.0001	0.94 (0.91–0.97)	0.0325
Secondary—CRS	Excluded	IgG	0.675	0.78 (0.72–0.83)	0.0011	0.98 (0.96–1.00)	0.6547
Secondary—CRS	Excluded	IgG4	0.32	0.70 (0.64–0.76)	0.0011	0.97 (0.95–1.00)	0.6547
Secondary—CRS	Included as negative cases	IgG	0.885	0.76 (0.71–0.82)	0.5316	0.98 (0.96–1.00)	0.0004
Secondary—CRS	Included as negative cases	IgG4	0.064	0.75 (0.69–0.81)	0.5316	0.91 (0.88–0.95)	0.0004
Secondary—CRS	Included as positive cases	IgG	0.675	0.54 (0.48–0.59)	0.0082	0.98 (0.96–1.00)	0.6547
Secondary—CRS	Included as positive cases	IgG4	0.32	0.49 (0.43–0.54)	0.0082	0.97 (0.95–1.00)	0.6547

CI, Confidence interval; CRS, composite reference standard, n/a, not available
^aP-values comparing sensitivities and specificities were determined by McNemar’s test

ISSN: 1756-3305