Final Report Summary - SERO-TB (Development of a specific serological kit for the diagnosis of TB) There is a great need for simple and robust diagnostic methods for the diagnosis of Tuberculosis (TB). From the basis of a through-screening process ten M. tuberculosis antigens have been identified, exhibiting potential as serodiagnostic TB antigens. Two to three of these antigens were selected with the aim of achieving the highest sensitivity and specificity in a setting with a high number of latent TB infections and Human immunodeficiency virus (HIV) co-infection. The selected antigens were incorporated into an Immunochromatographic test (ICT) which was optimised for the detection of M. tuberculosis-specific antibodies. Based on initial screening, four antigens with sensitivity of greater than 74 % in TB patients were selected to form the basis of the test. These antigens were re-optimised for large-scale production and then converted to a format suitable for use in a lateral flow assay. ICT prototypes were delivered to the partners in Turkey and Ethiopia and two rounds of testing were carried out. The results confirm proof of concept for the test, with clear bands being visible in positive samples. In addition, the test was rapid and extremely simple to use, with several hundreds of samples being screened, using samples from Denmark, Turkey and Ethiopia. Overall, however, the results were slightly disappointing, with both sensitivity and specificity being lower than would have been predicted based on the original screening. This may reflect a difference in the performance of the antigens in the ICT test versus ELISA or genuine regional differences (though it is worth noting that independent testing in Turkey and Ethiopia produced very similar results). Whatever the specific reason, it was agreed by all partners that the technology is extremely promising, but that further development will be needed before moving this test to commercial development. By the end of this project the partners had planned to identify the two-three best M. tuberculosis antigens of a serodiagnostic assay (in the event, they actually selected the four best antigens) and to have obtained performance data on the ICT prototype as a tool for detection active TB in a high and medium TB incident setting. As a part of this we expected to obtain data comparing the influence of TB incidence on the performance of an antibody based kit for diagnosis of active TB. These objectives have been met. The goal of the project was a cheap and more accessible diagnostic TB tool suitable for use at point of care, permitting earlier diagnosis of the disease and therefore earlier initiation of treatment. This is an important factor in controlling transmission of the disease. While the test developed is certainly robust and easy to use, we feel it currently lacks the resolving power needed for a truly useful diagnostic for TB: further basic study is therefore required. Related documents Final Report - SERO-TB (Development of a specific serological kit for the diagnosis of TB)
