DETECTION OF LIPOARABINOMANNAN ANTIBODIES IN PATIENTS WITH NEWLY ACQUIRED TUBERCULOSIS AND PATIENTS WITH RELAPSE TUBERCULOSIS

A commercially available dot immunoassay that employs the lipoarabinom annan antigen was evaluated for the serologic diagnosis of tuberculosi s. The test showed a high specificity (100%); however, its sensitivity was low (18.5%). Antibodies to lipoarabinomannan were detected in the sera of 7 of 71 patients with newly acquired tuberculosis and in sera of 10 of 21 patients with relapse tuberculosis. It has been shown by others that sera from patients with relapse tuberculosis had a higher concentration of antibodies and reacted with a greater variety of anti gens (native culture filtrates of Mycobacterium tuberculosis H37Rv) th an did sera From patients with newly acquired tuberculosis. Our data c onfirm the results of these previous studies as far as lipoarabinomann an is concerned. We conclude that the differences in the production of antibodies shown by the two groups of tuberculous patients (new and r elapse) must be taken into account when assessing the usefulness of se rologic tests for the diagnosis of tuberculosis.