%A Manandhar R %A Lemaster JW %A Butlin CR %A Brennan PJ %A Roche PW %T Interferon-gamma responses to candidate leprosy skin-test reagents detect exposure to leprosy in an endemic population %0 Journal Article %D 2000 %J International Journal of Leprosy and other Mycobacterial Diseases %P 0148-916X %V 68 %N 1 %X New tools for the detection of leprosy exposure in a community will be necessary for the eradication of leprosy. Candidate leprosy skin-test antigens derived f rom the fractionation of the leprosy bacillus into cytoplasmic and cell-wall proteins free of immuno-inhibitory mycobacterial lipoglycans and carbohydrates were used in an overnight blood test to determine whether exposure to leprosy can be detected by the production of the cytokine interferon gamma ( IFN-γ ). Strong IFN-γ responses were detected in leprosy contacts to both skin-test antigens compared with control subjects f rom the same endemic communities. There was little response in patients with tuberculosis. Responses were greatest in contacts with recent leprosy exposure. The implications of these findings for the application of these reagents in a field trial as skin tests to detect exposure to leprosy are discussed in light of the strong association between overnight IFN-γ to PPD and the tuberculin skin-test responses previously reported.