Jurnal Kedokteran dan Kesehatan: Publikasi Ilmiah Fakultas Kedokteran Universitas Sriwijaya Volume 9, No 3. 2022/DOI: 10.32539/JKK.V9I3.18894 p-ISSN 2406-7431; e-ISSN 2614-0411 Identification of -2849 IL-10 Gene Promoter Polymorphism in Leprosy Patient Desi Oktariana 1* , Arina P. Jatmiko 2 , Mutiara Budi Azhar 3 1 Departement of Clinical Pathology, Faculty of Medicine, Universitas Sriwijaya, Palembang, Indonesia 2 Medical Education Study Program, Faculty of Medicine, Universitas Sriwijaya, Palembang, Indonesia 3 Departement of Anatomy, Faculty of Medicine, Universitas Sriwijaya, Palembang, Indonesia Email : desioktariana@fk.unsri.ac.id received 9 Agustus 2022; accepted 7 September 2022 Abstract Leprosy is a chronic granulomatous disease. Leprosy is caused by M. leprae. However, not all exposure to M. leprae causes the disease. The condition of the host immune system determines the pathogenesis of leprosy. Interleukin-10 work as a pro- and anti-inflammatory cytokine. Polymorphism in the IL-10 gene promoter affects the amount of IL-10 secretion. The amount of IL-10 secretion determines the body’s response to M. leprae. The purpose of this study was to determine the distribution of -2849 IL-10 gene promoter polymorphism in leprosy patient at RSUP dr. Mohammad Hoesin Palembang. This research is an observational descriptive study with cross sectional design. Polymorphism identification was performed using PCR-RFLP. A total of 50 samples were identified. Most of the leprosy patients at RSUP dr. Mohammad Hoesin for the period January – February were < 50 years old (73.47%), male (66%), MB leprosy (92%), and came from Malay-South Sumatra ethnicity (53.06%). The genotype frequency distribution was GG 93.88%, AG 6.12%, and AA 0%. The frequency of allele G was 96.94% and allele A 3.06%. The majority of leprosy patients at RSUP dr. Mohammad Hoesin had wild-type genotypes. Keyword: leprosy, polymorphism, Interleukin-10 1. Introduction Leprosy is a chronic granulomatous disease that can cause disability. The etiology of this disease is Mycobacterium leprae. Leprosy manifestations can be found in the nerves and skin. Leprosy classified into paucibacillary (PB) and multibacillary (MB) by WHO. The PB type is leprosy with the number of skin lesions less than five while the MB type is leprosy with more than five skin lesions. 1,2,3 More than 200.000 new cases of leprosy are still found worldwide and one-third suffer from a disability. The spread of leprosy is uneven. As many as 80% of cases were reported from India, Brazil, and Indonesia, while many European countries have reported leprosy free. Indonesia is in the third rank of most cases with 15,910 new cases. The high incidence and the uneven spread of the disease has encouraged the development of epidemiological research on leprosy. Leprosy epidemiology research aims to answer the question of what factors cause the incidence of leprosy has not decreased in several countries. For a while, genetic association and close contact with MB leprosy patients are the strongest risk factors for leprosy (Misch et al., 2010). 1,4,5 Not all exposure to M. leprae causes disease. The difference in the level of the immune response in each individual determines the progression of the disease. 6 The body's first defense against M. leprae is the innate immune system. Since M. leprae is an obligate intracellular bacillus, the main innate immune cells for destroying bacteria are macrophages. In addition to eradicating bacteria, macrophages will activate the adaptive immune