A simple and practical assay for the antigen-specific detection of platelet antibodies.
BACKGROUND
The antigen-specific assays currently used for characterization of platelet (PLT)-reactive auto- and alloantibodies are too technically complex and impracticable for most routine laboratories. Here, a novel antigen-specific particle assay (ASPA) for PLTs similar to that of red blood cells is described.


METHODS
PLTs were solubilized and then incubated with red-dyed polystyrene particles coated with monoclonal antibodies (MoAbs) to various PLT glycoprotein complexes. These particles were directly tested for coating with autoantibodies (n = 8) or indirectly tested for serum autoantibodies (n = 33) or alloantibodies against HPA-1a (n = 4) or HPA-5b (n = 5). Serum samples from healthy blood donors (n = 100) served as negative controls.


RESULTS
Negative reactions were clearly distinguishable from positive reactions, and the results of the particle assay were in concordance with those obtained by the standard MoAb-specific immobilization of PLT antigen assay (MAIPA) in all cases with alloanti-bodies. In three patients, only the ASPA was able to detect autoantibodies that were completely undetectable by the MAIPA. In contrast, in only one patient, the MAIPA detected autoantibodies that the ASPA failed to detect.


CONCLUSIONS
In our opinion, the new ASPA is reliable, yet less complex and time-consuming than the currently available assays, and it can be implemented in any routine laboratory.
Meyer
Oliver
O
Institute for Transfusion Medicine, Charité-Medical University of Berlin, Berlin, Germany.
Agaylan
Ashraf
A
Borchert
Hans-Hubert
HH
Aslan
Tunay
T
Bombard
Stephane
S
Kiesewetter
Holger
H
Salama
Abdulgabar
A
D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood*; D001792:Blood Platelets / Q000276:immunology*; D016022:Case-Control Studies; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D015203:Reproducibility of Results
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D010980:Platelet Membrane Glycoproteins