Pseudothrombocytopenia: manifestation of a new type of platelet agglutinin.

Spuriously low electronic platelet counts heparin, oxalate, or citrate. Agglutination were obtained on blood collected in EDTA in the presence of EDTA was not inhibited from six patients. Platelet numbers on by heparin, a-tocopherol, or N-ethylmaleblood smears and electronic counts perimide, but was inhibitied by excess EDTA formed on blood collected in other antior divalent cation. The agglutinin was coagulants were normal. Plasma or sera temperature independent in five of the six from these patients agglutinated homolopatients and had the physical and imgous, as well as autologous platelets, in munologic characteristics of a gamma the presence of EDTA or DTPA, but agglobulin. The clinical significance and glutination did not occur in blood or mechanism of EDTA-dependent agglutinaplatelet-rich plasma anticoagulated with tion of platelets is unknown.