Specific immune-based diagnosis of tuberculosis

Current diagnostic tests for tuberculosis based on tuberculin have poor spe cificity, and both sos vaccination and exposure to non-tuberculosis mycobac teria produce a response similar to that induced by infection with Mycobact erium tuberculosis, The identification of regions of the M tuberculosis gen ome that are not present in BCG and non-tuberculous mycobacteria provides a unique opportunity to develop new highly specific diagnostic reagents. We describe the current status of attempts to exploit this information and sum marise recent research that has used defined antigens for an accurate and r apid test for tuberculosis infection based on the detection of T cells sens itised to M tuberculosis either by blood tests in vitro or skin tests in vi vo.