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, is
a chronic infectious disease affecting the skin and peripheral
nerves. The clinical presentation varies, from tuberculoid to
lepromatous forms due to differences in immune response.
Although slit skin smears (SSS) and histopathological analysis
are standard diagnostic methods. Modified Ziehl–Neelsen
staining is a widely used technique, but molecular methods
like polymerase chain reaction (PCR) offer superior sensitivity
and diagnostic utility. The aim of the study was to evaluate
histological findings, and PCR results in skin biopsies from
leprosy patients and to correlate histopathological and
molecular findings.
Material and Methods: A 4 mm skin punch biopsy was
obtained 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 conducted
for molecular detection of Mycobacterium leprae.
Results: The majority of patients were aged between 21–40
years, with 31 males (56.4%) and 24 females (43.6%).
Borderline lepromatous leprosy was the most prevalent
type. Of the 55 cases, 45.45% tested positive with modified
Ziehl–Neelsen staining, whereas PCR demonstrated a higher
positivity rate of 54.54%.
Conclusion:PCR is a valuable adjunct for diagnosing leprosy
in cases where modified Ziehl–Neelsen staining results are
negative. Despite its advantages, modified Ziehl–Neelsen
staining remains essential in low-resource settings due to its
accessibility and cost-effectiveness. Incorporating PCR in
casesZiehl–Neelsen staining shows negative results, it can
enhance the overall diagnostic yield.