Abstract: Objective The aim of this study was to explore the impact of peripheral blood mononuclear cell (PBMC) surface Toll-like receptor (TLR) 2/4 expression and small intestinal bacterial overgrowth (SIBO) on survival in patients with hepatocellular carcinoma (HCC) after transcatheter arterial embolization (TACE) therapy.Methods A retrospective clinical analysis was performed in 47 patients with HCC, who received TACE in our hospital between January 2013 and June 2016. 100 healthy persons were recruited for the controls during the same period. The expression intensity (EI) of TLR2 and TLR4 on PBMC surface were detected by flow cytometry, and the SIBO was assessed based on lactulose hydrogen breath test (LHBT). patients with HCC was 66.0%, significantly.Results The SIBO positive rate in higher than 6.0%(P＜0.05) in healthy persons, and the EI of TLR2⁺ cells was (94.7±12.3)geometric mean fluorescence(GMF), significantly higher than 【(26.4±4.2) GMF, P＜0.05】, the EI of TLR4⁺ cells was (43.1±8.7)GMF, significantly higher than 【(16.8±4.5) GMF, P＜0.05】 in healthy persons; the EI of TLR2⁺ cells in 31 HCC patients with SIBO positive was (109.3±16.8) GMF, greater than【(71.5±5.6) GMF, P＜0.05】 in 16 HCC patients with SIBO negative, and the EI of TLR4⁺ cells was (46.7±7.1)GMF, greater than 【(31.5±4.3) GMF, P＜0.05】 in patients with SIBO negative; six month after TACE, the EI of TLR2⁺ cells in 23 but one patients who lost with long survival was (45.7±5.8)GMF, significantly weaker than 【(65.6±12.5)GMF, P＜0.05】, the EI of TLR4⁺ cells was (21.5±4.3)GMF, significantly weaker than 【(30.1±7.4) GMF, P＜0.05】 , and the SIBO positive rate was 4.4%, significantly lower than 62.5%(P＜0.05) in 23 patients with short survival; the 3-year cumulative survival rate and 3-year cumulative event-free survival rate in 23 patients with TLR2 intensified expression were 17.4% and 13.0%, significantly lower than 52.2% and 43.5%(P＜0.05) in 23 patients with weak TLR2 expression, and the 3-year cumulative survival rate and 3-year cumulative event-free survival rate in 23 patients with TLR4 strong expression were 13.0% and 8.7%, also significantly lower than 56.5% and 47.8%(P＜0.05) in 23 patients with weak TLR4 expression, and they were 10.0% and 3.3% in 30 patients with SIBO positive, significantly lower than 81.3% and 75.0%(P＜0.05) in 16 patients with SIBO negative. Conclusion The expression of TLR2 and TLR4 on PBMC surface and SIBO could impact the survival of patients with HCC after TACE, and the mechanism needs further investigation.

Key words: Hepatocellular carcinoma, Transcatheter arterial embolization, Peripheral blood mononuclear cells, Toll-like receptor, Small intestinal bacterial overgrowth, Survival