European Journal of Molecular & Clinical Medicine, 7(2): 57--63 Research Article 57 European Journal of Molecular & Clinical Medicine, Vol 7, Issue 2 Assessed Valuate of Soluble Programmatic Cell Death Ligand 1 (PD-1) in Sera of Hepatitis C Virus in Iraqi Patients Seenaa Wdaah AlSalih 1 , Alaa Raisan Rashid 2 , Syakirah Samsudin 3 , Moatasem AlSalih 4* Copyright © 2020 The Author(s). This is an openaccess article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/ by/4.0/. INTRODUCTION Hepatitis is organ inflammatory disease in liver, HCV infection is a worldwide health problem. According to WHO appreciation, the number of people with HCV is estimated to be approximately rate wide world is 185 million individuals, of whom 703 800 die each year (GBD, 2015; WHO, 2016). Depending on the region and country varies Prevalence of HCV, sero developing countries, While being less than 2% (< 2%) in developed countries. (Hajarizadeh et al., 2013). In Iraq reported 1165536 thousand infection equal (3.21%) (Gower et al., 2014; lavanchy, 2011; Ghaderi-Zefrehi et al., 2016). Death Ligand 1 ( PD-1 ), also recognized as (CD 279) is a glycoprotein, molecular weight has 55 kDa , belongs to the CD28 of trans membrane proteins (Zhang et al.,2004). In the T cell hybridoma subject to cell death, PD-1 or CD 279 receptor was exposed as a genetic factor up regulated , in 1992 (Ishida et al.,1992). The Pdcd1 gene that is positioned on second chromosome which is the encoded for the PD1 (Keir et al., 2008). PD-1 represent a significant co inhibitory molecule engaged in an evolution of the chronic viral infections (Xiao et al., 2015). The scientist Lieping Chen is the one who discovered PD-L1, known also as CD274, in 1999 (Wang et al., 2017). The Cd274 gene which is located on chromosome 9 is the encoded for the PD-L1 (Keir et al., 2008). The inhibitory effects of PD -1 on T cells are via regulating the TCR signaling out of IL-2- dependent in addition to independent mechanisms (Patsoukis et al., 2012). The activation of Programmed cells Death-1 supports the inhibition a proliferation (CD4+ and CD8+ T) cells, which is correlated with cell apoptosis and the suppression of IL-2 secretion. The Programmed cells Death-1 Cascade Signaling influences the T cell response at the subsequent effector phase because up-regulated expression of PD-1 was revealed after persistent antigen intraction. Furthermore, CD8+ T cells turn out to be more prone to regulation by PD-1: PD-L exposure, because they create a down level of IL-2 (Carter et al., 2002). During the chronic phase HCV infection, the up-regulation of PD-1 is considered one of the apparatuses responsible for T cell impairment (Golden-Mason et al., 2008; Rutebemberwa et al., 2008). Generally, T cells depend on a set of signals to develop a strong and persistent response, and the transmitted signals are: 1. Signalling by the TCR. 2. Signalling by cytokines. 3. Signalling by costimulatory molecules expressed on antigen-presenting cells and T cells. When any one or more of the above signals are lost, this cause a defect in the response of T cells to HCV infection (Mescher et al., 2006). The persistence of viral infection and T- cell exhaustion in chronic HCV is related to the expansion of up-regulation of PD-1. Block the PD-1 ABSTRACT Objective: The present study aims at detecting the concentration of human PD-1 in samples taken from hepatitis C virus patients related to the healthy control group which studying the relation between viral load associated with (PD-1) concentration. subject of the treatment group content from 68 samples which is selected randomly from the patients with HCV, subdivide into 32 males and 36 females aged 23-76 years with 30 healthy individuals divided 20 males and 10 females. During first April to end of June 2020. ELISA kit from (Shanghai Yehua Biological Technology Company, China) was used to measure programmed death concentration. While Real time-PCR technique (Device Smart Cycler, USA) was used for calculating the viral load, according to Sacace Biotechnology kit. The result was a high concentration of PD-1 in patients 295.709±29.36 and 168.337 ± 80.906) compared to healthy (106.014±63.90, 110.176 ± 36.681). Respectively, and significant difference. and we found that PD1 concentration was directly proportional to viral load Conclusion: We have found that there is an enhancement in PD-1 concentration in patients associated with healthy control groups, and We also found that PD1 concentration was directly proportional to viral load, Whenever, increased the viral load, had risen the PD 1 concentration. Keywords: Hepatitis C Virus, HCV , PD-1, Viral Load, Chronic Hepatitis C. Seenaa Wdaah AlSalih 1 , Alaa Raisan Rashid 2 , Syakirah Samsudin 3 , Moatasem AlSalih 4* 1 The General Directorate of Education, Thi- Qar Governorate, Iraq. 2 Thi-qar University College of Education of pure Science. 3,4* UPSI university, Faculty of Science, Biology Department. Correspondence: Moatasem AlSalih UPSI University, Faculty of Science, Biology Department. E-mail: moatasemalsalih@gmail.com History:  Received: March 19, 2020  Accepted: June 25, 2020  Published: Sept 1, 2020 DOI: https://doi.org/10.31838/ejmcm.07.02.08