Emprego de marcadores séricos e salivares anti-PGL-1 como parâmetros de exposição ocupacional ao Mycobacterium leprae

Abstract

he coeffi cient of leprosy detection in Brazil has not decreased over the last years, probably due to the fact that non-treated bacilliferous infec- ted individuals are responsible for the Mycobacterium leprae transmission. Objectives: To evaluate the frequency of serum anti-PGL-1 IgG and salivary gA/IgM antibody positivity among students and health pro- fessionals under different degrees of exposure to M. leprae . Methods: One hundred and twenty seven individuals were evaluated according to the type and frequency of contact with leprosy patients and to the use of individual protection equipment at work. The serum and saliva samples were analyzed by enzyme linked immunosorbent assays. Results: Positive salivary anti-PGL-1 titers were found among 22% participants; only one individual showed positive serum anti-PGL-1 IgG. The highest frequency of positivity was found among those participants who presented more than three months of contact with leprosy patients and a strong correlation between salivary IgA and IgM was verifi ed in this group ( p <0.0001). The values of salivary anti-PGL-1 IgA and IgM were more elevated among those who did not wear masks during work, although the data analysis did not show any statistical signifi cance. Conclusions: Considering the hypothesis that the risk of development of the disea- se is 7.5 times greater in leprosy contacts with positive serum anti-PGL-1 antibodies, we believe that those who showed positive results for this serological marker should be monitored and examined periodically. In respect to the salivary antibodies, IgA can be detected in recent or chronic infections and IgM may be detected mostly in situations in which the pathogen is still present at the mucosal surfaces. We suggest therefore the use of serum and salivary anti- PGL-1 parameters for monitoring leprosy contacts in future strategies for interrupting M. leprae transmission.