A study of delayed hypersensitivity, lymphocyte transformation and leucocyte migration inhibition by M. xenopi and M. tuberculosis in patients harbouring these organisms

Abstract

Simultaneous skin, lymphocyte transformation and leucocyte migration inhibition tests with M. xenopi and M. tuberculosis antigens were carried out on 12 patients excreting M. xenopi and 8 infected with M. tuberculosis. Eight of the former reacted more strongly to M. xenopi than to mammalian PPD in the first 2 tests, one marginally so in skin tests. One patient excreting M. xenopi reacted more strongly in the skin tests only. All tuberculous patients had stronger lymphocyte transformation with mammalian than M. xenopi PPD, and with the exception of 2 who reacted almost equally to the 2 antigens, skin reactions were also stronger to mammalian PPD. There was good correlation between the results of skin and lymphocyte transformation tests when the latter were expressed as logarithms of differential counts of 3H-thymidine incorporation. There was also an excellent correlation in patients between the ratios of skin reaction and lymphocyte transformation to the 2 PPD preparations. Inhibition of leucocyte migration by M. xenopi and M. tuberculosis was observed in all patients and there was greater inhibition by M. tuberculosis, irrespective of the infecting species. There was no quantitative correlation between leucocyte migration inhibition and delayed hypersensitivity or lymphocyte transformation. Possible explanations for this difference between tests are discussed.