Release of platelet-activating factor in human pathology. I. Evidence for the occurrence of basophil degranulation and release of platelet-activating factor in systemic lupus erythematosus.
Basophil degranulation and release of platelet-activating factor (PAF acether) have been implicated in enhanced vascular permeability and immune complex deposition in rabbit acute serum sickness. PAF-acether is a phospholipid mediator of anaphylaxis, released from leukocytes of several mammalian species, including man, that aggregates platelets and releases their vasoactive amines. In this article, we evaluated the occurrence of basophil degranulation and release of PAF-acether in patients with systemic lupus erythematosus. In the acute phases of the disease, basophils were in vivo degranulated, and the amount of PAF-acether releasable from leukocytes was markedly reduced. During remission or in the latent phases of the disease, when the number of metachromatically staining basophils increased. in an vitro degranulation and release of PAF-acether were observed after DNA challenge. Electron microscopy studies demonstrated that basophils indeed degranulated in response to DNA. These studies also showed the interaction between degranulating basophils and human platelets which aggregated even if the other two pathways of human platelet aggregation, i.e., the ADP- and the arachidonic acid-dependent pathways, were blocked. The concomitance of basophil degranulation and release of PAF-acether, together with the morphologic evidence of the interaction between degranulating basophils and aggregated platelets, was strongly suggestive of release of PAF-acether from basophils in systemic lupus erythematosus.
D000818:Animals; D001491:Basophils / Q000378:metabolism*; D001779:Blood Coagulation Factors / Q000378:metabolism*; D001792:Blood Platelets / Q000502:physiology; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D011817:Rabbits
D001779:Blood Coagulation Factors