Abstract: Objective The aim of this study was to analyze the efficacy of 3D regimen (paritaprevir/ritonavir/ombitasvir combined with dasabuvir sodium) in the treatment of patients with chronic hepatitis C (CHC) with genotype 1b infection and low serum viral load. Methods A total of 77 patients (naïve patients in 62 and re-treated in 15) with CHC with gene 1b infection and low serum viral load (less than 7.0 log₁₀IU/ml) were recruited in our hospital between May 2019 and May 2020, and all received 3D regimen for 3 months and followed-up for 3 months. The early virological response (EVR), end treatment virologica response (ETVR) and sustained virologic response (SVR) were evaluated, and plasma interferon-γ (IFN-γ) and interferon-inducible protein 10 (IP-10) levels were detected by ELISA. Results The EVR, ETVR and SVR12 in naïve patients were 51.6%, 100.0% and 100%, and were 46.7%, 100.0% and 100% in re-treated patients (P>0.05); serum HCV RNA negativities in the 77 patients with CHC at the end of one month, two months, three months and three months after treatment were 93.5%, 98.7%, 100.0% and 100.0%, and serum HCV RNA loads were (1.1±0.1)log₁₀IU/ml,(1.1±0.1)log₁₀IU/ml,(1.1±0.1)log₁₀IU/ml and (1.0±0.1)log₁₀IU/ml, respectively, significantly lower than at presentation; serum alanine aminotrasaminase levels were (16.8±4.1)U/L, (15.3±3.9)U/L, (11.1±3.2)U/L and (12.0±3.4)U/L, all significantly lower than , and serum aspartate aminotransferase levels were(20.4±4.7)U/L,(17.9±4.4)U/L,(18.0±5.1)U/L and (14.7±4.8)U/L, all significantly lower than at presentation; plasma IFN-γ levels were (46.9±5.8)pg/ml, (50.2±6.3)pg/ml, (57.0±6.9)pg/ml and (51.3±4.6)pg/ml, significantly higher than , while plasma IP-10 level were (100.5±36.1)pg/ml, (72.1±22.8)pg/ml, (66.8±13.4)pg/ml and (68.7±12.5)pg/ml, significantly lower than at presentation. Conclusion 3D regimen could achieve a better short-term efficacy in the treatment of no matter naïve or re-treated patients with CHC with genetype 1b infection with low serum viral loads, and warrants further and long-term observation.

Key words: Hepatitis C, Paritaprevir/Ritonavir/Ombitasvir, Dasabuvir s, Therapy