Geraldo Gomes dos Santos

Pesquisa de Mycobacterium leprae em biópsias de mucosa oral por meio da reação em cadeia da polimerase

BACKGROUND - Hansens disease is endemic in South America, which accounts for 3% of total world cases, and particularly in Brazil, which accounts for 85% of all South American cases. The bacteria can be found in the oral mucosa with no evident signs of infection, and only very sensitive laboratory assays can detect its presence. OBJECTIVES - The aim of this study was to ascertain if the M. leprae genome can be detected by PCR in small punch biopsy specimens from the oral mucosa of patients with Hansens disease. METHODS - The normal oral mucosas of seven multibacillary Hansens disease patients were biopsied. Five of them were under treatment at the time of the study. Diagnosis of Hansens disease could be determined by conventional hematoxylineosin and Fite-Faraco staining for M. leprae in only one patient. This patient had not received treatment prior to the time of the biopsy. The paraffin embedded specimens were submitted to PCR for M. leprae. RESULTS - Six out of seven cases showed positivity for M. leprae, and the remaining case showed positivity for Mycobacterium sp., demonstrating the high sensitivity and specificity of this method. CONCLUSIONS - PCR is a fast, easy and reliable method for routine investigation of mycobacterial infection, even during nonsymptomatic periods. Diagnosis can be achieved through a simple oral biopsy at an outpatient clinic.