Hepatitis C virus core antigen testing: Role in diagnosis, disease monitoring and treatment

Table 1 Time point and thresholds reported to predict response or non-response

Ref.	n	Genotype	Time point	Threshold	PPV	NPV
Wada et al[25]	64	gt 2	1 wk	100 fmol/L	96% (SVR)	100% (SVR)
Tedder et al[9]	41	u.n.	week 12	HCV RNA > 2log reduction	70% (EOTR)	74% (EOTR)
				HCV core Ag negative	85% (EOTR)	93% (EOTR)
			within 2 wk	HCV RNA > 2log reduction	86% (EOTR)	72% (EOTR)
				HCV core 1log reduction	75% (EOTR)	76% (EOTR)
Vermehren et al[26]	160	1	1	Undetectable	90.9% (RVR)	92.8% (RVR)
			2	Undetectable	79.4% (RVR)	97.6% (RVR)
			4	Undetectable	47.6% (RVR)	100% (RVR)
Tamai et al[28]	106	1b	2	HCV RNA 1log reduction	65% (SVR)	90% (SVR)
			2	HCV core Ag 1log reduction	64% (SVR)	97% (SVR)
			2	HCV RNA 2log reduction	86% (SVR)	67% (SVR)
			2	HCV core Ag 2log reduction	93% (SVR)	69% (SVR)
Ross et al[12]	29	1/4	week 12	2log reduction	45% (SVR)	100% (SVR)
	9	2/3	week 12	2log reduction	87.5% (SVR)	1/1 (SVR)
Fujino et al[23]	60	1b	day 3	500 fmol/L	96.7% (SVR)	46.6% (SVR)
			day 7	500 fmol/L	90% (SVR)	76.7% (SVR)
			day 14	500 fmol/L	96.7% (SVR)	53.3% (SVR)
			day 28	500 fmol/L	100% (SVR)	26.7% (SVR)

PPV: Positive predictive value; NPV: Negative predictive value; HCV: Hepatitis C virus.