Types of Measurements

• Direct Test: Detection of antibodies bound to patient’s platelets.
• Indirect Test: Detection of antibodies in patient’s serum by incubating the serum with allogeneic platelets.

Platelet Antibody Assays

• Flow Cytometry Assay: A flow cytometer uses fluorescent antibodies to detect IgG or IgM antibodies bound to autologous or allogeneic platelets.

Platelet Antigen Determination

• DNA Typing: This test uses the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) to determine the genetic code variations responsible for the different platelet antigens (HPA-1 through HPA-6).
• Platelet Antibody Determination (MAIPA): Serologic assay using donor platelets of known platelet types to determine the specificity of platelet antibodies.

Heparin Antibody Assay

• Heparin-Platelet Factor 4 Assay: Enzyme linked assay using a complex of heparin and platelet factor 4 (PF4) to capture antibody developed during type II heparin-induced thrombocytopenia (HIT).