Immunohistochemical and histopathological analyses of cutaneous innervation to improve the diagnostic efficacy in hansen disease skin lesion

Abstract Background The diagnosis of Hansen disease (HD) can be difficult when acid-fast bacilli are not detected in the patient's skin sample. Objective To demonstrate that detailed morphological analysis of nonspecific inflammatory and/or noninflammatory alterations in dermal nerves as well as skin adnexa in leprosy-suspected biopsy samples could improve the efficacy of histopathological diagnosis. Methods Patients with one to five skin lesions were enrolled in the study and classified into three groups by skin histopathology findings: Hansen disease (HD, n = 13), other diseases (OD, n = 11), and inconclusive cases (INC, n = 11). We quantified dermal nerve damage via the nerve lesion index (NLI) and PGP9.5-immunoreactive axon quantitative index in dermal nerves (AQI). We also measured inflammatory involvement of adnexa in cutaneous samples as indirect evidence of HD. Results We observed a higher median endoneurial inflammatory infiltrate NLI (HD = 0.5; INC = 0; OD = 0; p