TABLE 2.

Performance of rapid immunochromatographic test and the reference ELISA with sera with quantified levels of RF units

Serum group	RF value (IU/mg)	Reference ELISA (OD [interpretation])	Rapid test (score [inter- pretation])
RF 0 to 850 (IU/mg)	20	0.136 (negative)	0 (negative)
	596	0.157 (negative)	3 (positive)
	653	0.041 (negative)	0 (negative)
	660	0.071 (negative)	0 (negative)
	667	0.072 (negative)	0 (negative)
	670	0.018 (negative)	0 (negative)
	685	0.079 (negative)	0 (negative)
	690	0.163 (negative)	0 (negative)
	821	0.158 (negative)	0 (negative)
	825	0.048 (negative)	0 (negative)
	845	0.037 (negative)	0 (negative)
RF 850 to 1,500 (IU/mg)	869	0.066 (negative)	0 (negative)
	879	0.066 (negative)	0 (negative)
	882	0.204 (negative)	0 (negative)
	895	0.163 (negative)	1 (positive)
	900	0.169 (negative)	1 (positive)
	928	0.088 (negative)	0 (negative)
	1270	0.138 (negative)	1.5 (positive)
	1350	0.051 (negative)	0 (negative)