Platelet Satellitism

Abstract

Platelet satellitism, an in vitro phenomenon of platelet rosetting around polymorphonuclear neutrophils, is observed exclusively in blood treated with EDTA as an anticoagulant at room temperature. Neither heparin nor citrate produces rosetting. The proposed mechanisms include immunologic bonding through EDTA-dependent antiplatelet and antineutrophil IgG autoantibodies directed against the glycoprotein IIb/IIIa complex and Fc g receptors of platelets and neutrophils, respectively, and nonimmunologic adherence mediated by thrombospondin or the alpha-granule protein of other platelets. The results of both in vivo and in vitro platelet-function tests are normal. Phagocytosis of platelets by polymorphonuclear leukocytes and monocytes is sometimes seen. Severe platelet satellitism is an important cause of spurious thrombocytopenia.

Platelet Satellitism in a Patient with Bronchial Asthma

“…2,3 Till date, the underlying mechanism of platelet satellitism is not well understood but there is evidence that platelet satellitism is mediated by activation of EDTA dependent IgG autoantibodies directed against the glycoprotein IIb/IIIa complex of the platelets and the Fc(γ) receptor III (FcγRIII) of neutrophils. 1,7,8 It is believed that EDTA, a calcium chelating ion causes alteration in the platelet glycoprotein IIb/IIIa and neutrophil Fc(γ) receptor exposing antigenic structure in membrane which is recognize by autoantibodies IgG resulting in formation of platelet satellitism. 7,8 It is still unclear about the production of IgG auto antibodies and their interaction mechanism with target molecule of platelet and neutrophil in patient with platelet satellitism.…”

“…4 However it is postulated that immunologic phenomenon due to presence of natural antibodies or non-immunologic mechanism due to thrombospondin causes platelets to aggregate around polymorphonuclear leukocyte. 1 We present a case of Platelet satellitism in a patient diagnosed with bronchial asthma.…”

“…Platelet satellitism is a rare and interesting in-vitro phenomenon observed in a blood smear prepared form blood sample anticoagulated with Ethylenediaminetetraacetic acid (EDTA). 1,2 It is characterize by platelet rosetting around neutrophils and occasionally in other blood cell too, resulting in pseudo thrombocytopenia. 3 To date, exact mechanism of platelet satellitism is not clearly understood.…”

Platelet satellitism in a trauma patient

“…It is observed in peripheral blood smears prepared from blood samples anticoagulated with EDTA, but not in blood samples treated with heparin or sodium citrate (1–3). Platelet rosetting is observed mainly around PMN, but occasionally also around eosinophils, basophils, lymphocytes or monocytes, too.…”

Platelet Satellitism in Lupus Erythematosus Resolving after Treatment

“…Also, recently there has been a discussion about its well-recognized importance in modulating inflammation and hemostasis [1,2,3,4,5,6]. …”