Genetic association of interleukin-6 polymorphism (-174 G/C) with chronic liver diseases and hepatocellular carcinoma

Table 1 Studies examining the role of interleukin-6 polymorphism (-174 G/C) in hepatitis C virus and hepatitis B virus infection

Ref.	Country	Ethnicity	Cases	Controls	Genotyping method	Association with chronic hepatitis/response to therapy
Barrett et al[20]	Ireland	Caucasian	158	-	PCR-SSP	Positive significant/-
Nattermann et al[23]	Germany	Caucasian	210	100	Cytokine genotyping tray	-/Uncertain
Falleti et al[25]	Italy	Caucasian	121	-	PCR-RFLP	Positive significant /-
Park et al[26]	South Korea	Asian	1046	-	PCR-SBE	NS/-
Ribeiro et al[27]	Brazil	American1	26	41	PCR-SSP	NS/-

¹White, black and hispanic. PCR-SSP: Polymerase chain reaction - single specific primer; PCR-RFLP: Polymerase chain reaction - restriction fragment length polymorphism; PCR-SBE: Polymerase chain reaction - single base primer extension assay; NS: Not significant.

Table 2 Studies examining the role of interleukin-6 polymorphism (-174 G/C) in alcoholic and autoimmune liver diseases

Ref.	Country	Ethnicity	Cases	Controls	Genotyping method	Association
Carulli et al[33]	Italy	Caucasian	79	114	PCR-RFLP	Positive significant (NAFLD)
Fernández-Real et al[34]	Spain	Caucasian	32	-	PCR-RFLP	Positive significant (diabetes and lipid abnormalities) (G allele)
Marcos et al[48]	Spain	Caucasian	258	101	TaqMan genotyping	NS (alcoholic liver disease)
Fan et al[53]	China	Asian	77	-	PCR-RFLP	Positive significant (PBC)

PCR-RFLP: Polymerase chain reaction - restriction fragment length polymorphism; NAFLD: Non-alcoholic fatty liver disease; PBC: Primary biliary cirrhosis.

Table 3 Studies examining the role of interleukin-6 polymorphism (-174 G/C) in hepatocellular carcinoma

Ref.	Country	Ethnicity	Cases	Controls	Genotyping method	Association with HCC
Nieters et al[65]	China	Asian	250	250	PCR-RFLP	NS
Ognjanovic et al[66]	United States	American1	120	230	5’nuclease Taqman allelic discrimination assay	Positive significant
Falleti et al[67]	Italy	Caucasian	219	-	PCR-RFLP	Positive significant
Giannitrapani et al[15]	Italy	Caucasian	105	-	PCR-RFLP	Positive significant

¹White, black and hispanic. PCR-RFLP: Polymerase chain reaction - restriction fragment length polymorphism; HCC: Hepatocellular carcinoma; NS: Not significant.