title: Complement (C5-a)-induced granulocyte aggregation in vitro. A possible mechanism of complement-mediated leukostasis and leukopenia.
abstract: Activated plasma complement will induce biphasic aggregation of human granulocytes dectable by standard nephelometric techniques. The responsible active component was suggested to be C5a by molecular weight and heat-stability assays; moreover, aggragating activity was ablated by anti-C5 but not anti-C3 antibodies. C5a prepared by trypsinization of purified C5 reproduced the aggregating activity of whole activated plasma, whereas plasma from a C5-deficient donor did not support aggregation. Embolization of granulocyte aggregates might be a previously unsuspected cause of leukostasis and pulmonary damage in various clinical situations where intravascular complement activation occurs.
mesh_terms: D002449:Cell Aggregation; D003182:Complement C5 / Q000172:deficiency / Q000378:metabolism; D003165:Complement System Proteins / Q000378:metabolism; D006098:Granulocytes / Q000502:physiology*; D006487:Hemostasis; D006801:Humans; D007962:Leukocytes / Q000502:physiology*; D007970:Leukopenia / Q000276:immunology*; D008854:Microscopy, Electron; D011652:Pulmonary Circulation; D015054:Zymosan / Q000494:pharmacology
chemical_list: D003182:Complement C5; D003165:Complement System Proteins; D015054:Zymosan