Human peripheral blood lymphocytes sensitised to PPD respond to in vitro stimulation with increased expression of CD69 and CD134 activation antigens and production of Th-1 type cytokines

Individuals sensitised to Mycobacterium tuberculosis antigens by infection, vaccination or Mantoux test generate specific memory cells. The response t o in vitro restimulation with PPD is observed as the lymphoid cell prolifer ation and production of Th-l type cytokines. Cell-mediated immune response was measured by Mantoux test lymphocyte blast transformation test estimatio n of IFN-gamma production (Quantiferon, ELISPOT), and expression of CD69 an d CD134 molecules on the T-helper lymphocytes (CD4(+)). All the methods use d were compared for parity of the results. According to Mantoux: test resul ts, the patients could be distributed into two groups: responder and non-re sponder group. Induration in Mantoux test after a new contact with PPD in n on-responders was smaller than 5 mm, they produced only small amounts of IF N-gamma, lymphocyte blast transformation was poor, and expression of CD69 a nd CD134 was low. In responders reaction was much more intensive in all tes ts measured. We conclude that the reactivity of memory cells to nk tubercul osis antigens can be effectively detected by Mantoux test. The same was tru e also for the in vitro tests presented but in addition the in vitro tests give more information about the mechanism involved in the immune response a gainst M. tuberculosis.