Table 1.

Role of polymorphisms of genes encoding cytokines and some regulatory proteins in chronic hepatitis B virus infection

Cytokine	Allele/polymorphism	Effect	Ref.
IL-1
IL-1α
IL-1β	-511C	Persistent infection	[20-22]
IL-1RN	2	Protective against HBV infection	[18]
IL-6	-174 G/C	No effect	[26]
IL-8	-251AA	Protective against HBV-related cirrhosis	[28]
IL-10	-1082G	Virus clearance, lower HBV viral load, protective against HBV infection	[30,31]
		Persistent HBV infection	[35]
	-592CA	Virus clearance	[35]
		Persistent HBV infection	[36]
	IL-10R K47E	Persistent, chronic infection	[38,99]
IL-18	-148C	Virus clearance	[40]
	+8925G	Virus clearance	[40]
	+13925C	Virus clearance	[40]
	-137C	Protective against HBV	[43,44]
	-607AA	Inhibition of HBV DNA replication	[43,44]
IL-28B		Virus clearance, prevent HBV progression	[46]
		No effect	[51]
TNF-α	-863A	Virus clearance, persistent infection	[68,71,77]
	-238A	Persistent infection	[37,58-62,71]
	-308A	Progressive disease	[55,58,66,77]
		Protective against chronic HBV infection	[76]
	-857CC	Persistent infection	[37,61,62,68]
		Protective against chronic HBV infection	[75]
IFN-γ	+874AA	Viral load, persistent infection	[54]
TGF-β1	-509C	Development of cirrhosis	[80]
	Codon 10T	Development of cirrhosis	[80,83]
		Progression to hepatocellular cancer	[81,82]

HBV: Hepatitis B virus; IL: Interleukin; TNF: Tumor necrosis factor; IFN: Interferon; TGF: Tumor growth factor.