Human platelet aggregation by mixed cryoglobulins.
Glomerulonephritis in idiopatic mixed cryoglobulinemia represents perhaps a glomerular damage by immune complexes. In this study, a sigmoidal-like curve was obtained after addition of 13 different mixed cryoglobulins to both autologous and isologous platelet-rich plasma, tested in platelet aggregometer. The lag phase of the curve corresponds to platelet phagocytosis of cryoglobulin-binding ferritin, as shown in electron microscopy and the optical density decrease phase corresponds to the aggregation of platelets that shows the same ultrastructural characteristics of ADP-induced platelet aggregation. This platelet aggregation is inhibited by different drugs. Intraglomerular platelet aggregation by cryoglobulins might play a key role in determining the glomerular damage in cryoglobulinemia by the release of nucleotides and vasoactive amines.
D001792:Blood Platelets / Q000648:ultrastructure; D002118:Calcium; D003450:Cryoglobulins / Q000494:pharmacology*; D003864:Depression, Chemical; D005293:Ferritins; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D010973:Platelet Adhesiveness / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects*
D003450:Cryoglobulins; D006493:Heparin; D005293:Ferritins; D002118:Calcium