[Inhibition of platelet migration. A simple technic for typing of PLA1 and the detection of platelet allo- and autoantibodies].

In vitro, platelets can migrate in an active way. This migration can be immunologically inhibited through specific antibodies. This test (PMI-test) can be easily carried out in any laboratory. In that study this test was used: 1) For the detection of anti-platelet allo-antibodies in neonatal thrombopenia. Out of nine cases studied, two anti-PLA1 were identified and three anti-HLA antibodies (anti-B8, anti-B17+21 and a polyspecific serum) detected thanks to the micro-lymphocyto-toxicity test were confirmed by that test. 2) To find free auto-antibodies in the sera of patients suffering from idiopathic thrombopenic purpura. In five cases out of twelve the presence of auto-antibodies could be shown, that is 41,6%. In some cases, the auto-antibodies showed a certain degree of specificity as it had already been pointed out in other studies. When the thrombopenias were associated with other diseases, all the tests were negative. 3) For the PLA1 typing of donors: 1,85% donors submitted to the test proved to be PLA1 negative. 4) To identify anti-HLA antibodies and to compare this test with the micro-lymphocyto-toxicity-test: the anti-A2, A11, B8, B17, CW3 and CW4 antibodies used titrated the same in both tests. 5) Eventually to study the possible action of ABO-system antibodies in this test; this study shows that only sera containing immune antibodies can bring about an inhibition of the incompatible platelet migration. The sensitivity of the PMI-test which has previously been mentioned as equal to platelet-lysis and superior to aggregometry and platelet factor-3 release, is superior to the complement fixation test since with an 1/16 titre in PMI test for the two anti-PLA1 antibodies, the latter could not be detected through the complement fixation test; it seems to be equal to platelet indirect radioactive Coombs since both sera titrate in the same way.