Serum hepatitis B surface antigen levels predict treatment response to nucleos(t)ide analogues

Table 2 Hepatitis B surface antigen predict virological response or hepatitis B e antigen loss/seroconversion during nucleos(t)ide analogues therapy

NAs	Treatment duration	Case number	Comments	Ref.
Entecavir	2 yr	95	HBeAg (+) patients: baseline HBsAg cutoff level of 9550 IU/mL yielded the highest predictive value in predicting the VR	[31]
			HBeAg (-) patients: baseline HBsAg or HBsAg decline levels could not predict VR
Entecavir	2 yr	101	HBeAg (+) patients: HBsAg level at baseline was an independent factor of HBeAg loss/seroconversion	[32]
			HBsAg level < 3000 IU/mL at 3 mo of treatment was an independent factor for achieving VR
			HBeAg (-) patients: HBsAg levels could not predict VR
Entecavir	More than 2 yr	50	Low baseline HBsAg levels were the most significant factor for achieving VR at year 2 of treatment	[33]
Tenofovir	6 yr	104 HBV + HIV	A higher level of HBsAg decline in patients with HBeAg loss compared to patients remaining HBeAg-positive (2.5 log IU/mL vs 1.8 log IU/mL, P < 0.001)	[36]
			Baseline HBsAg levels could not predict HBeAg loss

VR: Virological response; NAs: Nucleos(t)ide analogues; HBsAg: Hepatitis B surface antigen; HBeAg: Hepatitis B e antigen; HBV: Hepatitis B virus; HIV: Human immunodeficiency virus.