The Role of IL-6 Gene Polymorphism in Multidrug-Resistant Tuberculosis Patients in Iraq

Abstract

Background: Tuberculosis (TB) remains to be a leading cause of morbidity and mortality in developing countries, and the incidence of the disease is increasing in developed. One-third of the world’s population is infected by Mycobacterium tuberculosis (Mtb). Still, only about 5% of infected individuals develop the disease within the first year of infection, and another 5% develop the disease later in life. Aim of the study: Is to investigate the relationship between the levels of Interleukin 6 (IL-6) and detection of multidrug-resistant tuberculosis (MDR-TB) in Al-Diwaniyah population. Patients and methods: The current study included 120 patients with tuberculosis who were classified into two groups. The first group included 60 TB patients who were sensitive to anti TB drugs and 60 patients with multi-drug resistance (MDR) based on gene Xpert. The study also included 60 healthy individuals serving as a control group. Demographic characteristics of study and control groups were retrieved. IL-6 (-572G/C) genotype polymorphism was carried out using polymerase chain reaction (PCR) and according to the instruction of the providing company. Serum level of IL-6 was also measured by ELISA according to the instruction of the providing company. Results: It has been observed that genotype CC was more frequent in sensitive TB patients than both MDR TB patients and control subjects, 73.3 % versus 60 % and 61.7 %, respectively. Serum IL-6 level was significantly higher in MDR TB patients than in control group (p = 0.007), and there was no significant difference in its level between sensitive and MDR TB patients (p = 0.284). Conclusion: IL-6 gene polymorphism is not associated with multidrug resistance in TB patients; however, Serum IL-6 level was significantly higher in MDR TB patients than in the control group.