Perfil de marcadores sorológicos, salivares e moleculares de Mycobacterium leprae entre contatos intradomiciliares de pacientes com hanseníase

Abstract

Leprosy household contacts are group at high risk of developing the disease. We investigated the presence M. leprae DNA in nasal mucosa and anti-PGL1 serum IgG/IgM and salivary IgA/IgM antibodies from leprosy household contacts (n=135) in two endemic regions, Ceara, Brazil. Good correlation between serum IgM and IgG isotypes was observed both in MB and in PB leprosy household contacts (r = 0.39, p <0.0001). However, their levels were much different (p <0.0001). Among the contacts positive for serum IgM, 74 (87%) were found to be negative for serum IgG. In respect to the salivary antibodies, PB leprosy household contacts showed correlation between IgA and IgM (r = 0.60, p <0.0001); the same was observed in MB leprosy contacts (r = 0.77, p <0.0001). It was observed that in 75.3% of the leprosy household contacts who were positive to serum anti-PGL1, their salivary antibodies were negative. On the other hand, 50% of the leprosy household contact who were negative to serum anti-PGL1 antibodies, their salivary antibodies were positive. M. leprae DNA was found in nasal swab in 9 MB household leprosy contacts (10.6%) and in 3 PB leprosy contacts (6.0%). We concluded that quantitative analysis of serum and salivary anti-PGL1 in leprosy contacts is necessary for mounting strategies to survey subclinical leprosy infections in order to prevent development of the disease.