PLATELET SATELLITISM - EXPERIMENTAL STUDIES

  • 1 January 1980
    • journal article
    • research article
    • Vol. 42  (3) , 343-355
Abstract
Platelet satellitism (PS), the in vitro phenomenon of platelets rosetting about nonlymphocytic leukocytes, is an uncommon and poorly understood finding reported in the EDTA-anticoagulated blood of patients with a wide variety of clinical conditions. Experimental studies were presented, investigating the nature of this phenomenon by utilizing the blood of patients with platelet satellitism. Wet preparation studies and EM (transmission and scanning) demonstrated the morphologic sequences involved in the phenomenon, including eventual phagocytosis of platelets by neutrophils. Results of varying conditions such as time, temperature and anticoagulant were described. All of 5 patients tested had cryofibrinogenemia. Certain blood components from all of 3 patients tested were capable of inducing PS in normal whole blood, whereas blood components from normal subjects usually were not. In 1 patient (A), the PS-inducing capability appeared to be present in plasma and platelets. In another patient (B) the PS-inducing capability was present in platelets (in 1966 and 1975) and also in the cryosupernate of serum and plasma; among various antisera, antifibrinogen had the greatest ability to reduce the degree of PS in patient blood; addition of moderate amounts of CaCl2 and/or MgCl2 did not diminish the phenomenon; 2 sisters and 2 daughters demonstrated no PS. In a 3rd patient (C) the PS-inducing capability appeared largely concentrated in the cryoprecipitable fraction of plasma. There are apparently different factors in the patients'' blood resulting in PS. Further studies showed PS could be induced in normal blood by adding certain nonprimate antihuman antisera (anti-Ig[immunoglobulin]M, antialbumin or antifibrinogen) and also by adding some preparations of normal washed platelets to the same individual''s normal whole blood. The phenomenon of PS can apparently be produced by factors other than those specifically present in patients with PS. Antigen-antibody complexes, formed in vivo (mixed cryoglobulinemia) or in vitro, did not result in PS when mixed with normal blood. PS can apparently result from the presence of several different factors, usually proteins (in conjunction with EDTA), which probably attach to the surface of platelets apparently resulting in some alteration (such as change in surface charge) causing the platelets to be attracted to and phagocytosed by neutrophils.