Characterization of Sera with Discordant Results from Reverse Sequence Screening for Syphilis

Table 1

INNO-LIA syphilis score and FTA-ABS test results of 23 discordant sera between CIA and TP-PA results.

TP-PA	INNO-LIA syphilis; score results (𝑁)	FTA-ABS; results (𝑁)
RPR(−)/TP-PA(−); (𝑁 = 16)	Positive (1)	Reactive (1)
	Indeterminate (5)	Reactive (1); Non-reactive (4)
	Negative (10)	Non-reactive (10)
RPR(−)/TP-PA(±); (𝑁 = 7)	Positive (6)	Reactive (6)
	Indeterminate (1)	Non-reactive (1)
RPR(+)/TP-PA(−); (𝑁 = 1)	Negative (1)	Non-reactive (1)
RPR(+)/TP-PA(±); (𝑁 = 2)	Positive (2)	Reactive (2)

CIA: chemiluminescence immunoassay, RPR: rapid plasma regain, TP-PA: Treponema pallidum particle agglutination assay, FTA-ABS: fluorescent treponemal antibody absorbed, 𝑁: number, ±: indeterminate.