Immune complexes and IgG-Fc receptors on human platelets in essential mixed cryoglobulinemia.
An enzyme-linked immunosorbent assay (ELISA) using wells coated with normal platelets has been tested in order to quantitate cell-bound immune complexes (ICs) by measuring the uptake of alkaline phosphatase-conjugated antibodies to IgG in the immune complexes. All patients with essential mixed cryoglobulinemia had levels of serum IgG ICs above control values; a poor accordance was found between levels of ICs detected by this method and those obtained using the conglutinin method. The presence of these complexes was correlated with human platelet aggregation: platelets aggregated in vitro when cryoglobulins with higher IgG/IgM ratio were present. This type of ICs could be critical also for platelet activation and aggregation in vivo.
D000936:Antigen-Antibody Complex / Q000032:analysis* / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology / Q000648:ultrastructure*; D003449:Cryoglobulinemia / Q000097:blood* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects; D011961:Receptors, Fc / Q000032:analysis*; D017452:Receptors, IgG; D011971:Receptors, Immunologic / Q000032:analysis*
D000936:Antigen-Antibody Complex; D011961:Receptors, Fc; D017452:Receptors, IgG; D011971:Receptors, Immunologic