Detection of drug-dependent platelet antibodies using immobilized Staphylococcal protein A.
Serum samples from eight patients suspected of having drug-induced immunologic thrombocytopenia provoked by a variety of medications were tested for drug-dependent platelet antibodies with a newly developed assay that forms rosettes of antibody-coated platelets around Staphylococcal protein A-Sepharose beads. The same samples were then tested with immunofluorescence and 51Cr-release assays. Seven of eight patients (87.5%) tested positive for drug-dependent antibodies by the rosette assay. In contrast, two of eight (25.0%) and one of eight (12.5%) patients tested positive for drug-dependent antibodies by immunofluorescence and 51Cr release, respectively. These results demonstrate that the new rosette method is significantly more sensitive and specific for the detection of drug-dependent platelet antibodies than either immunofluorescence or 51Cr release.
Christie
D J
DJ
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis.
Lennon
S S
SS
D000906:Antibodies / Q000032:analysis*; D001792:Blood Platelets / Q000276:immunology*; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D012397:Rosette Formation; D013205:Staphylococcal Protein A; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced
D000906:Antibodies; D013205:Staphylococcal Protein A