A genetic variant in toll-like receptor 5 is linked to chemokine levels and hepatocellular carcinoma in steatohepatitis.

Abstract

Bacterial translocation drives liver disease progression. We investigated whether functional genetic variants in toll-like receptor 5 (TLR5), the receptor for bacterial flagellin, affect the risk for hepatocellular carcinoma (HCC). Healthy controls (n=212), patients with alcohol abuse without liver disease (n=382), and patients from a discovery cohort of alcohol-associated cirrhosis (n=372 including 79 HCC cases), a validation cohort of alcohol-associated cirrhosis (n=355 including 132 HCC cases), and a cohort of cirrhosis due to nonalcoholic steatohepatitis (NASH) (n=145 including 62 HCC cases) were genotyped for the TLR5 rs5744174 and rs5744168 polymorphisms. Chemokine levels were measured by ELISA in patients' sera and supernatants of flagellin-stimulated healthy monocytes. Frequency of the TLR5 rs5744174 TT genotype was similar in healthy controls (33%), controls with alcohol abuse (34%), and patients with alcohol-associated cirrhosis in the discovery (28%), validation (33%), and NASH cohort (31%). The TT genotype was enriched in patients with versus without HCC in the discovery, validation, and NASH cohort (41% vs 25%; 39% vs 29%; 40% vs 24%; p<.05 each). This genotype remained a risk factor for HCC (OR=1.9; p=.01) after multivariate correction for age, gender, diabetes, and carriage of the PNPLA3 148M variant. Interleukin-8 induction in monocytes from healthy controls and serum levels of interleukin-8 and CXCL1 from cirrhotic patients with the TT genotype were significantly increased versus C allele carriers. The TLR5 rs5744174 polymorphism, affecting immune response to flagellin, is linked to occurrence of HCC in cirrhosis caused by steatohepatitis.