EVALUATION OF A COMMERCIAL IMMUNODIAGNOSTIC KIT INCORPORATING LIPOARABINOMANNAN IN THE SERODIAGNOSIS OF PULMONARY TUBERCULOSIS IN GHANA

We evaluated 'Mycodot', a commercially marketed immunodiagnostic test for tuberculosis which detects antibodies to lipoarabinomannan antigen . Serum was tested from 52 patients with newly diagnosed smear-positiv e pulmonary tuberculosis, of whom 20 were HIV-positive and 32 HIV-nega tive. Control sera were taken from 40 patients of whom 20 had acute no n-tuberculous lobar pneumonia and 20 patients had no respiratory disea se. The test was found to have a very high specificity of 97.5% (35% C l:92.5-100%). However, the sensitivity in HIV-negative patients was 56 % (95% Cl:39-73%), and was substantially lower at 25% (95% Cl:6-44%) i n HIV-positive patients. In conclusion: 'Mycodot' was found to be a hi ghly specific and easily performed assay. However, the poor sensitivit y, especially in HIV-infected patients, renders it unlikely to be usef ul either as a primary or adjunctive diagnostic test for tuberculosis, particularly in countries with a high prevalence of HIV. A larger tri al of this assay in Ghana was not deemed necessary.