RESUMEN
INTRODUCTION: Leprosy is an ancient and chronic infectious disease caused by 2 mycobacteria (Mycobacterium leprae and Mycobacterium lepromatosis). Recently, our research group observed that HES-1, an innate cellular component of the Notch signaling pathway, is related to the pathogenesis of leprosy. Therefore, it could be helpful in its detection. OBJECTIVE: To determine the expression of HES-1 in the skin of patients with paucibacillary (PB) leprosy. METHODS: A cross-sectional, descriptive, observational study was conducted. Forty-five skin samples from patients with leprosy were evaluated (30 samples from MB leprosy and 15 from PB leprosy) using immunohistochemistry of HES-1 and S-100. RESULTS: PB leprosy biopsies revealed a reduction of HES-1 in 66.7% of the epidermis, 80% of the eccrine glands, and 62.5% of the hair follicles of these patients, with statistical differences in the control group (P < 0.0001). Besides, HES-1 showed similar utility to S-100 immunostaining in detecting the MB and PB leprosy. CONCLUSIONS: HES-1 is a transcriptional factor also reduced in PB patients' epidermis and skin appendages. Finally, our data show that HES-1 could be a biomarker in diagnosing PB and MB leprosy.