Study of Histopathological Spectrum of Leprosy Patients with Special Reference to Conventional PCR for Detection of Mycobacterium leprae in Skin Biopsy Samples: A Prospective Observational Study

Abstract

Introduction: Leprosy, caused by Mycobacterium leprae, isa chronic infectious disease affecting the skin and peripheralnerves. The clinical presentation varies, from tuberculoid tolepromatous forms due to differences in immune response.Although slit skin smears (SSS) and histopathological analysisare standard diagnostic methods. Modified Ziehl–Neelsenstaining is a widely used technique, but molecular methodslike polymerase chain reaction (PCR) offer superior sensitivityand diagnostic utility. The aim of the study was to evaluatehistological findings, and PCR results in skin biopsies fromleprosy patients and to correlate histopathological andmolecular findings.Material and Methods: A 4 mm skin punch biopsy wasobtained from 55 clinically diagnosed leprosy patients,preserved in formalin, and processed for histopathology.Staining was performed using hematoxylin and eosin (H&E)and modified Ziehl–Neelsen stains. PCR testing was conductedfor molecular detection of Mycobacterium leprae.Results: The majority of patients were aged between 21–40years, with 31 males (56.4%) and 24 females (43.6%).Borderline lepromatous leprosy was the most prevalenttype. Of the 55 cases, 45.45% tested positive with modifiedZiehl–Neelsen staining, whereas PCR demonstrated a higherpositivity rate of 54.54%.Conclusion:PCR is a valuable adjunct for diagnosing leprosyin cases where modified Ziehl–Neelsen staining results arenegative. Despite its advantages, modified Ziehl–Neelsenstaining remains essential in low-resource settings due to itsaccessibility and cost-effectiveness. Incorporating PCR incasesZiehl–Neelsen staining shows negative results, it canenhance the overall diagnostic yield.