Further studies of platelet rosettes around granulocytes in Behcet's syndrome.

Rosettes of platelets around granulocytes-platelet satellitism-previously described in Behcet's syndrome led to the discovery of a case that may have been 80 years in duration. A strong relationship between calcium ions and the phenomenon was suggested by its specificity in edetic-acidanticoagulated blood, and the subsequent migration of platelets on supravital preparation from around neutrophils upon addition of 0.2 M calcium chloride to heparinized EDTA-treated blood. Plasma from the patient was able to cause the phenomenon with donor granulocytes and platelets. Platelet agglutinins were also demonstrable. Specificity in Behcet's syndrome is possible, but remains unproved.