Application of nucleoside analogues to liver transplant recipients with hepatitis B

Table 1 Structure, mechanism of action, and incidence of resistance of currently available nucleoside analogues[12,20,21]

Drug name	Structure	Mechanism of action	Incidence of drug resistance
LAM	Cytidine analogue	Premature chain termination	High
LDT	Thymidine analogue		High
ETV	Guanosine analogue	Inhibits priming RT	Low
		Inhibit negative and positive strand synthesis
ADV	Adenosine analogue	Premature chain termination	High
TDF		Inhibit negative strand synthesis	Unknown

ADV: Adefovir dipivoxil; ETV: Entecavir; HBV: Hepatitis B virus; LAM: Lamivudine; LDT: Telbivudine; NA: Nucleoside analogue; RT: Reverse transcriptase; TDF: Tenofovir.

Table 2 Treatment selections for liver transplant recipients with HBV recurrence and drug resistance[10,16,84]

HBV recurrence after liver transplant	LAM resistance	Add ADV or switch to ETV or TDF
	ADV resistance	Switch to TDF
	ETV resistance	Switch to TDF
	HBIG resistance	Switch to NAs monotherapy or combined therapy

HBV: Hepatitis B virus; LAM: Lamivudine; ADV: Adefovir dipivoxil; ETV: Entecavir; TDF: Tenofovir; HBIG: Hepatitis B immune globulin; NA: Nucleoside analogue.

Table 3 Strategies for preventing hepatitis B virus recurrence for different groups of hepatitis B virus-related liver transplant recipients

Low risk recipient (undetectable HBV DNA before transplantation)	NAs + HBIG[52]
	NAs + short-term HBIG, then switch to NAs combined therapy[58,59] or NA monotherapy (ETV or TDF)[66]
	NAs combined therapy[54,68]
	NA monotherapy (ETV or TDF)[69] (Further studies are needed)
High risk recipient (detectable HBV DNA before transplantation or with limited antiviral options)	NA + long-term HBIG[56]
Recipient with HBcAb positive donors	NA + HBIG[91,92]
	NA monotherapy[93,94]
	Active immunization[95]

ADV: Adefovir dipivoxil; ETV: Entecavir; HBcAb: Hepatitis B virus core antibody; HBIG: Hepatitis B immune globulin; HBV: Hepatitis B virus; LAM: Lamivudine; NA: Nucleoside analogue; TDF: Tenofovir.