Human Antibodies 28 (2020) 141–148 141 DOI 10.3233/HAB-190400 IOS Press CXCL9 chemokine level is associated with spontaneous clearance and sustained virological response in Egyptian Chronic Hepatitis C patients receiving direct acting antivirals Ashraf A. Tabll a,∗ , Mamdouh S. Afifi b , Abd-Allah S. El-Etrawy c , Salah M. El-Kousy b , Martina Smolic d and Yasmine S. El Abd a,∗ a Microbial Biotechnology Department, Genetic Engineering and Biotechnology Research Division National Research Centre, Giza, Egypt b Chemistry Department, Faculty of Science, Menufia University, Menufia, Egypt c Chemistry Department, Basic Science Center and Pharmaceutical Organic Chemistry Department, College of Pharmaceutical Sciences and Drug Manufacturing, Misr University for Science and Technology, 6 th October City, Egypt d Department of Pharmacology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia Abstract. BACKGROUND: Chronic Hepatitis C virus (HCV) infection is associated with progressive liver inflammation which in turn leads to cirrhosis and finally causes hepatocellular carcinoma (HCC). By different escape mechanisms, the virus succeeds to evade the innate and acquired immune responses to establish chronic infection. AIM: This study aimed to evaluate the level of chemokine CXCL9 and its correlation with some biochemical parameters in different subjects of HCV patients. MATERIALS AND METHODS: A total of 83 persons participated in this study including healthy subjects without both HCV antibodies and HCV RNA (22.9%), HCV treated responders accomplished SVR post treatment, with HCV antibodies and absence of HCV RNA (24.1%), spontaneous or natural clearance patients, with positive HCV antibodies and negative HCV RNA without treatment (26.5%) and chronic HCV-patients, with both positive HCV antibodies and HCV RNA with no treatment (26.5%). HCV RNA was quantitated by real time PCR and serum CXCL9 level was measured by ELISA commercial kit pre-coated with human MIG/CXCL9 antibody. Assessment of biochemical and hematological parameters was carried out. RESULTS: Data showed that, the level of CXCL9 was significantly increased in chronic individuals (627.1 pg/ml) (P< 0.001) than spontaneous clearance (107.76 pg/ml) and responder subjects (117.28 pg/ml) (P  0.05). No correlation has been found between CXCL9 level and viral load. Furthermore, CXCL9 levels correlated variably with some biochemical and hematological parameters according to each subject. CONCLUSION: Serum Chemokine CXCL9 level is associated with spontaneous clearance of HCV and response to HCV treatment, which may be identified as a predictive marker among HCV patients. Keywords: CXCL9, chemokine, Chronic Hepatitis C virus, spontaneous clearance * Corresponding authors: Ashraf A. Tabll, Microbial Biotech- nology Department, Genetic Engineering and Biotechnology Re- search Division National Research Centre, El Behooth Street, Dokki, Giza, 12622, Egypt. E-mail: Ashraftabll@yahoo.com. Yasmine S. El Abd, Microbial Biotechnology Department, Genetic Engineer- ing and Biotechnology Division, Technology and Innovation Com- mercialization Office, National Research Centre NRC, El Behooth Street, Dokki, Giza, 12622, Egypt. E-mail: yasminco@yahoo.com. ISSN 1093-2607/20/$35.00 c  2020 – IOS Press and the authors. All rights reserved