title: A plasma inhibitor of platelet aggregation in patients with Argentine hemorrhagic fever.
abstract: Hemorrhage in patients with Lassa fever is associated with the presence of a circulating plasma inhibitor of platelet aggregation. This study was to determine whether patients with Argentine hemorrhagic fever (AHF) develop a similar inhibitor. Normal platelets showed significantly weaker aggregation responses to a sub-maximal dose of adenosine diphosphate (ADP) when mixed with plasma from 10 patients with AHF (mean percent of control +/- 1 SE = 57.2 +/- 6.7%) compared to those mixed with plasma from 9 viral control patients (79.5 +/- 4.1%; P less than 0.05) and 9 febrile patients with septicemia (103.8 +/- 3%; P less than 0.001). Plasma from 3 patients with severe AHF inhibited in a dose-dependent fashion the aggregation responses of normal platelets to collagen, sodium arachidonate, a calcium ionophore (A23187), and ristocetin; none of 4 samples from convalescent AHF patients showed this inhibitory activity. The platelet inhibition was sudden in onset and unaffected by a 30 min pre-incubation, not neutralized by convalescent plasma with high titer antibody to Junin virus, and abolished after heating plasma from an AHF patient at 56 degrees C for 30 min. Hemorrhage in AHF is associated with the presence of a circulating inhibitor of platelet aggregation, and disturbed hemostasis in arenavirus-induced hemorrhagic fevers may have a common basis.
authors.affiliation: University College, London, England.
authors.forename: D
authors.initials: D
authors.lastname: Cummins
authors.forename: F C
authors.initials: FC
authors.lastname: Molinas
authors.forename: G
authors.initials: G
authors.lastname: Lerer
authors.forename: J I
authors.initials: JI
authors.lastname: Maiztegui
authors.forename: R
authors.initials: R
authors.lastname: Faint
authors.forename: S J
authors.initials: SJ
authors.lastname: Machin
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000914:Antibodies, Viral / Q000097:blood; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D006477:Arenaviruses, New World / Q000276:immunology; D000001:Calcimycin / Q000494:pharmacology; D003094:Collagen / Q000494:pharmacology; D006478:Hemorrhagic Fever, American / Q000097:blood*; D006801:Humans; D010974:Platelet Aggregation; D010975:Platelet Aggregation Inhibitors / Q000097:blood*; D012310:Ristocetin / Q000494:pharmacology; D013696:Temperature
chemical_list: D000914:Antibodies, Viral; D001095:Arachidonic Acids; D010975:Platelet Aggregation Inhibitors; D012310:Ristocetin; D016718:Arachidonic Acid; D000001:Calcimycin; D000244:Adenosine Diphosphate; D003094:Collagen