Comparison of serum vitamin D level and vitamin D receptor gene FokI polymorphism in leprosy patients with and without trophic ulcers: protocol for a case-control study

<ns3:p> Background Leprosy, or Hansen’s disease, is a chronic infectious disease that primarily affects the skin and peripheral nervous system, often leading to disabilities, including trophic ulcers (TU). The role of vitamin D and vitamin D receptor ( <ns3:italic>VDR</ns3:italic> ) gene polymorphisms in the development of TU among leprosy patients remain unclear. Objective This study aims to investigate the differences in serum 25-hydroxyvitamin D [25(OH)D] levels and the frequency of <ns3:italic>VDR</ns3:italic> gene <ns3:italic>FokI</ns3:italic> polymorphism between leprosy patients with and without TU, and to evaluate their association with the occurrence of TU. Methods This Institutional Review Board-approved, single-center, observational, analytic case-control study will enroll adult leprosy patients from the Dermatology and Venereology Clinic at Dr. Cipto Mangunkusumo Hospital in Jakarta, Indonesia. Participants will be divided into cases (patients with TU) and controls (patients without TU). Serum 25(OH)D levels will be measured using a chemiluminescence immunoassay, and <ns3:italic>FokI</ns3:italic> polymorphism detection is conducted through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. A total of 82 participants (41 cases and 41 controls) will be recruited. Statistical analysis will be performed to evaluate the differences and associations. Results Data collection commenced in March 2024 and was completed in September 2024, during the Indonesia’s dry season. Data analysis and reporting are expected to be finalized by January 2025. Discussion The findings of this study will enhance the current understanding of the role of the vitamin D axis in the development of TU among leprosy patients. This could lead to new therapeutic strategies, such as vitamin D supplementation or personalized medicine based on genetic profiling, potentially reducing the burden of TU among leprosy patients. </ns3:p>