Neonatal alloimmune thrombocytopenia: detection and characterization of the
responsible antibodies by the platelet immunofluorescence test
AE von dem Borne, EF van Leeuwen, LE von Riesz, CJ van Boxtel and CP Engelfriet
Platelet immunofluorescence, together with other serologic tests on
platelets, lymphocytes, and granulocytes, was used to investigate the sera
of 38 mothers with newborns who suffered from thrombocytopenia. In sera of
33 mothers, platelet-specific IgG alloantibodies were demonstrable. Three
sera also contained HLA antibodies, of which two were only detectable in
the lymphocyte cytotoxicity test. Two other sera contained
granulocyte-specific alloantibodies. In sera of 2 mothers, antibodies were
found that reacted with all cell types in all tests. However, after further
analysis, it became clear that platelet- specific alloantibodies were
probably also present in these 2 sera. In 29 cases, the specificity of the
platelet alloantibodies was anti-Zwa-- PlA1. One serum contained antibodies
directed against a new antigen, Baka. This new antigen was defined after
the investigation of the family and a small-scale population study. Two
other sera had platelet antibodies with still undefined specificities. In
all positive sera, IgG platelet alloantibodies were detected, and sometimes
IgM antibodies were also present. The IgG antibodies were mostly of the
IgG1 subclasses, but sometimes IgG3 and/or IgG4 was also found. In a few
sera, only IgG3 antibodies were detected. In our series, we found no
increased frequency of blood group ABO compatibility between mother and
child, although it has been described by others and is well known to occur
in rhesus alloimmunization. Of all the tests used, the platelet
immunofluorescent test, especially the test on paraformaldehyde-fixed
platelets in suspension, gave the best results in the detection of platelet
antibodies in neonatal alloimmune thrombocytopenia.
Volume 57,
Issue 4,
pp. 649-656,
04/01/1981
Copyright © 1981 by The American Society of Hematology
