[Cellular immunity: in vitro leukocyte migration inhibition does not correlate with the tuberculin skin test]

The leukocyte migration inhibition test (LMIT) is said to be an in-vitro correlate of cell mediated immunity in vivo. The authors' series of experiments, however, in which they compared skin tests and LMIT (taking the same tuberculin for both tests), showed wed no correlation between the two tests. The discrepancy between these results and those of other authors may be due to the fact that the authors worked under sterile conditions. It is known that contamination even by minute amounts of endotoxin may alter the results of in-vitro tests of cell mediated immunity. The authors therefore question the value of the LMIT as an in-vitro counterpart of the skin test.