Table 1.

Definitions of treatment responses

Rapid virologic response (RVR)	Qualitative HCV RNA assay done at 4 weeks comes out to be negative (<50 lU/mL)
Early virologic response (EVR)	Quantitative HCV RNA assay done at 12 weeks:
	Comes out to be negative — called early virologic clearance (EVC) or aviremic response
	Shows a decline in the HCV RNA titer (compared with the pretreatment assay) of ≥ 2 log — called partial virologic response (PVR) or viremic response
Nonresponders	Quantitative HCV RNA assay done at 12 weeks showing either no decline in the HCV RNA titer (compared with the pretreatment assay) or a decline of < 2 log
End-of-treatment response (ETR)	Qualitative HCV RNA assay done on completion of the recommended duration of the course comes out to be negative
Sustained virologic response (SVR)*	Qualitative HCV RNA assay done 24 weeks after completion of the recommended duration of the course comes out to be negative
Relapsers	Qualitative HCV RNA assay done on completion of the recommended duration of the course is negative; but 24 weeks later, the assay done to confirm SVR comes out to be positive

^*Achievement of SVR is generally considered as the marker of eradication of HCV infection. Almost all such patients show EVC or PVR on 12-week assay