Failure of levamisole to alter the lepromin reaction.

In a study of 37 leprosy patients, the oral administration of levamisole failed to provoke an increase in both the Fernandez and Mitsuda reactions to lepromins of human and armadillo origin. We interpret this as evidence against an effective specific immunostimulatory capability of levamisole in leprosy patients under the conditions of the study. Current knowledge of the mechanism of levamisole action supports the concept that the fundamental immunologic defect in lepromatosus leprosy may reside in the lymphocyte and not the macrophage, or the respective related functions of these two cell forms.