Evaluation of three Mycobacterium leprae monoclonal antibodies in mucus and lymph samples from Ziehl-Neelson stain negative leprosy patients and their household contacts in an indian community

RESUMO

Mucus and lymph smears collected from leprosy patients (9) and their household contacts (44) in the Caño Mochuelo Indian Reservation, Casanare, Colombia, were examined with monoclonal antibodies (MoAb) against Mycobacterium leprae. The individuals studied were 5 borderline leprosy (BB) patients, 4 with a lepromatus leprosy (LL), all of whom were undergoing epidemiological surveillance after treatment and 44 household contacts 21 of the LL and 23 contacts of the BB patients. The MoAb were reactive with the following M. leprae antigens 65 kd heat shock protein, A6; soluble antigen G7 and complete antigen, E11. All the samples were tested each of the MoAb using the avidin-biotin-peroxidase technique and 3,3 diaminobenzidine as chromogen. The patients and household contacts studied were all recorded as Ziehl-Neelson stain negative. The MoAb which showed optimal reaction was G7, this MoAb permited good visualization of the bacilli. Five patients with BB diagnosis and one with LL were positive for G7; of the BB patients' household contacts, 9 were positive for G7; 7 of the LL patients' household contacts were positive for the same MoAb. MoAb G7 allowed the detection of bacillar Mycobacterium spp. compatible structures in both patients and household contacts. G7 permited the visualization of the complete bacillus and could be used for early diagnosis and follow-up of the disease in patients.