02178nas a2200361   4500000000100000008004100001260001300042653002400055653001100079653003000090653002300120653001200143653001600155653002500171653002500196653001500221653000900236653001800245653003400263653003000297653002000327100001300347700001400360700001200374700001500386700001100401700001300412245014700425300001100572490000700583520121200590022001401802       1988                            d  c1988 Jul10aAntigens, Bacterial10aHumans10aHypersensitivity, Delayed10aImmunity, Cellular10aleprosy10aMacrophages10aMicroscopy, Electron10aMycobacterium leprae10aPhagocytes10aSkin10aT-Lymphocytes10aT-Lymphocytes, Helper-Inducer10aT-Lymphocytes, Regulatory10aTuberculin Test1 aKaplan G1 aSheftel G1 aJob C K1 aMathur N K1 aNath I1 aCohn Z A00aEfficacy of a cell-mediated reaction to the purified protein derivative of tuberculin in the disposal of Mycobacterium leprae from human skin.  a5210-40 v853 a<p>The purpose of this study was to evaluate the effects of a delayed-type cell-mediated immune response to Mycobacterium tuberculosis antigen on the Mycobacterium leprae load in the skin of leprosy patients. Twelve patients with the lepromatous form of leprosy have been injected intradermally with 5 units of the purified protein derivative of tuberculin (PPD). Ten individuals responded with areas of induration ranging from 12 to 21 mm in diameter, and two were unresponsive (less than 10 mm). Twenty-one days thereafter, the injected and control sites were biopsied, and the histology, number of acid-fast bacilli, nature and phenotype of the emigrant cells, and ultrastructural characteristics of the lesions were evaluated. Eight of the 10 responding patients showed reductions in the number of acid-fast bacilli by factors ranging from 5 to 10,000. Two responders and both nonresponders exhibited no discernible decline in the number of organisms. The reduction in bacillary load was correlated with an intense mononuclear cell infiltrate, the maintenance of a high CD4+ T-cell/CD8+ T-cell ratio, the formation of granulomata, and the extensive destruction of previously parasitized macrophages.</p>  a0027-8424