Interleukin-17 Gene Polymorphisms and Hepatitis B Virus Infection in a Sample of Iraqi Patients
Authors: Kadhim Hayder A. , Slama Foued Ben Hadj 
Published: October 2024

Hepatitis B, a chronic inflammatory liver condition, constitutes a significant global health issue, with 3 million new cases and over 1 million deaths annually (when combined with hepatitis C). The infection may be acute or chronic, and it transmits horizontally by contact with biological fluids such saliva, blood, semen, tears, vaginal secretions, or perinatal fluids following childbirth, which are transferred from mother to infant. Infections can be easily prevented with immunization, typically administered shortly after birth; nevertheless, if neglected, chronic hepatitis B may lead to severe outcomes, including liver cancer or cirrhosis. Interleukin-17A, a pro-inflammatory cytokine, is essential in the immune response to many infections and is implicated in autoimmune diseases. The cytokine interleukin-17 (IL-17A) is only secreted by activated T cells. cDNA of IL-17 has been isolated and cloned from murine hybridomas (cytotoxic T lymphocyte antigen 8 (CTLA-8)). Cytokine imbalance is a crucial factor in the progression and growth of the hepatitis B virus (HBV). A cross-sectional study was conducted including 180 patients with HBV infection at the Digestive and Liver Diseases Teaching Hospital in Baghdad province, from December 14, 2022, to February 15, 2023. This study comprised two groups: the first group consisted of 40 HBV antibody-positive patients, while the second group included 40 HBV antibody-negative patients, along with a control group of 20 individuals. A blood sample of 5 ml was collected from each patient, divided into 2 ml in an anticoagulated EDTA tube and 3 ml in a gel tube. Whole blood with anticoagulated samples was utilized under optimal conditions for DNA extraction, while serum was isolated from blood for biochemical tests. The study comprised 180 patients, categorized into three groups: HBV Positive, HBV Cleared, and Control. The HBV Positive cohort consists of 99 individuals, comprising 54 males (54.45%) and 45 females (45.45%). The average age in this cohort is 42.52 years, accompanied by a standard deviation of 15.13 years. Of these individuals, 84 (84.85%) are wed. The HBV Cleared group has 45 individuals, including 24 males (53.34%) and 21 females (46.67%). The average age in this cohort is 48.43 years, with a standard deviation of 13.98 years. A predominant 39 persons (86.67%) are wed. The Control group comprises 36 individuals, primarily male, consisting of 24 men (66.67%) and 12 females (33.34%). Genotype distribution for two genetic markers, rs2275913 and rs10484879, among three groups: HBV Positive, HBV Negative, and Control. In the HBV Positive group for the rs2275913 marker, the AA genotype is present in 30 patients, the AG genotype in 36 patients, and the GG genotype in 36 patients. In the HBV Negative group, the AA genotype is observed in 9 patients, the AG genotype in 12 patients, and the GG genotype in 21 patients. Multiple research investigations have concentrated on the role of SNPs in the IL17A gene, particularly rs2275913 and rs10484879, in the susceptibility to chronic HBV infection. The polymorphisms were specifically examined for their possible impact on immune response and disease progression in patients infected with HBV. A study of the Han Chinese population demonstrated a significant correlation between the GG genotype and G allele of rs2275913 and an increased risk of HBV infection, suggesting a causal relationship with heightened susceptibility to viral infection.