A Case of Platelet Satellitism with Platelet Phagocytosis by Neutrophils and Platelet-neutrophil Agglutination

Platelet satellitism is a rare phenomenon in which platelets adhere to the surface of neutrophils; in addition, platelet phagocytosis by neutrophils and monocytes is rare event. Although its clinical significance and pathophysiology are still unclear, platelet-neutrophil agglutination seems to be the end point of a process that is initiated by platelet satellitism and causes pseudothrombocytopenia and pseudoneutropenia. Differentiating pseudothrombocytopenia is essential to avoid unnecessary diagnostic testing and treatments. This report describes an unusual case of a 64 yr old man who presented with left flank pain and pseudothrombocytopenia, which was caused by platelet satellitism with platelet phagocytosis by neutrophils and platelet-neutrophil agglutination. Platelet satellitism occurred in the presence of ethylenediaminetetraacetic acid (EDTA) at room temperature or 4degrees C, but not at 37degrees C; however, platelet-neutrophil agglutination and pseudoleukopenia were observed in EDTA-treated blood only after a 2-hr incubation period at room temperature. Additionally, platelet satellitism could be induced in packed blood cells from a normal individual during a mixing assay with this patient's plasma. To the best of my knowledge, this is the first reported case of platelet satellitism with platelet phagocytosis by neutrophils and platelet-neutrophil agglutination in Korea.

Satelitismo plaquetario: primeros dos casos reportados en Costa Rica / Plaquetary satellitism: first two cases reported in Costa Rica

Menos de 100 casos de Satelitismo Plaquetario se han descrito desde que en 1963, Field y MacLeod describieron por primera vez este fenómeno. Estos son los dos primeros casos del fenómeno descritos en la literatura Costarricense. El satelitismo plaquetario se observo en muestras sanguíneas con EDTA como anticoaguante y alrededor de los polimorfonucleares. A diferencia de otros casos descritos en la literatura la fagocitosis plaquetaria era evidente y no se observó pseudotrombocitopenia.

Field and MacLeod first reported the platelet satellitosis or satellitism in 1963 and to date is has been observed in no more than 100 cases. These are the first two cases reported in Costa Rica. This phenomenon occurred only in blood anticoagulated by EDTA and around polymorphonuclears. Pseudotrombocytopenia was not observed but platelet phagocytosis was evident.