High serum platelet-to-lymphocyte ratio as a risk factor for severe erythema nodosum leprosum

Abstract

Introduction: Reactions in leprosy occur during the disease's progression and can result in disability. Hematological examination by calculating the platelet-to-lymphocyte ratio (PLR) can potentially predict leprosy reactions, especially erythema nodosum leprosum (ENL). This study aimed to asses the association between high PLR as a risk factor for severe ENL in multibacillary (MB) leprosy patients at Prof. dr. I G. N. G. Ngoerah General Hospital, Denpasar, Bali. Methods: This case-control study uses data from medical records of leprosy patients treated at Prof. dr. I G. N. G. Ngoerah General Hospital from February 2020 to December 2023. The case group comprises MB leprosy patients diagnosed with severe ENL, while the control group consists of MB leprosy patients without ENL. Platelet-to-lymphocyte is calculated by comparing absolute platelet counts with absolute lymphocyte counts from routine blood tests. Data were analyzed using SPSS version 26 by Chi-square test, sensitivity, specificity test and multivariate analysis. Result: A total of 48 subjects included in this study. The analysis results in this study showed that PLR was a risk factor for severe ENL (OR: 4.20; 95%CI: 1.228 - 14.365). Meanwhile, the cut-off point value used to categorize PLR was 151.37, with a sensitivity of 74% and specificity of 58%. Multivariate analysis showed that PLR had an adjusted odds ratio (aOR) of 2.38 (95%CI: 0.39 - 14.54; p= 0.347). Conclusion: High PLR might be associated with an increased risk of severe ENL reactions in MB leprosy patients.