PNPLA3 rs738409C/G polymorphism in cirrhosis: relationship with the aetiology of liver disease and hepatocellular carcinoma occurrence.Liver Int. 2011 Sep; 31(8):1137-43.LI
BACKGROUND AND AIM
The PNPLA3 rs738409 C>G polymorphism has been found to be strongly associated with non-alcoholic fatty liver disease and with alcoholic liver disease. Whether the PNPLA3 rs738409 polymorphism could be a risk factor for the development of hepatocellular carcinoma (HCC) in cirrhosis patients is unknown.
This study included 483 (344 males) consecutive Italian patients of Caucasian ethnicity affected by cirrhosis, of whom 279 had undergone transplantation for end-stage liver disease while 204 had been referred to our liver and transplant unit for the diagnosis of cirrhosis. The aetiologies were hepatitis C virus=209, hepatitis B virus=76, alcohol=166, metabolic=32. Ile148Met rs738409 transversion was genotyped using an restriction fragment length polymorphism-based assay.
The genotype frequencies of the rs738409 polymorphism were distributed differently in patients with cirrhosis C/C=168, C/G=220, G/G=95 vs controls C/C=218, C/G=175, G/G=35 (P<0.0001). Among cirrhotics, the G allele was over-represented in alcoholic/metabolic (0.505) vs viral (0.368, P<0.001) liver disease. Patients with cirrhosis complicated by HCC were more likely to be G/G homozygotes (38/141) than the remaining patients (57/342, P<0.02). At multivariate analysis, the PNPLA3 rs738409 polymorphism was confirmed to be an independent predictor of HCC occurrence (odds ratio 1.76, 95% confidence interval 1.06-2.92, P<0.05). HCC rates increased from 13/116 (11.2%; female C/(*) carriers), to 97/295 (32.9%; male C/(*) carriers and female G/G homozygotes), to 31/72 (43.1%; male G/G homozygotes) (P<0.0001).
The PNPLA3 rs738409 C>G polymorphism is associated with cirrhosis. In synergy with gender, this polymorphism is a strong predictor of HCC occurrence among patients with cirrhosis.