Platelet satellitism in autoimmune hemolytic anemia.

Platelet satellitism is a rare phenomenon observed in blood smears obtained from blood anticoagulated with EDTA with an estimated frequency at 0.008%. It is characterized by platelet rosetting around neutrophils and in rare cases around other blood cells, which may causes pseudothrombocytopenia. Our case involves a 26-year-old female patient with autoimmune hemolytic anemia (AIHA). Blood smear with EDTA as an anticoagulant had platelet satellitism whereas the phenomenon was not observed in tubes with different anticoagulants (citrate, heparin) and capillary blood. This phenomenon was still observed four weeks after the patient's discharge. Furthermore, we discuss the possible pathophysiological mechanisms of platelet satellitism proposed in the literature. To our knowledge, this is the first case of platelet satellitism reported in AIHA.