title: Grey platelet syndrome: evidence for alpha-granule localization of the platelet plasminogen activator inhibitor-1 pool.
abstract: The case of an 11-year-old boy with grey platelet syndrome is described. Platelets had the typical grey and ghostly appearance on May-Grünwald/Giemsa staining, caused by the absence of alpha granules confirmed by electron microscopy. Alpha granule protein content, i.e., beta-thromboglobulin and platelet factor 4, was less than 3% of normal and alpha granule secretion in response to thrombin was not detectable photometrically. The plasminogen activator inhibitor-1 pool in the patient's platelets was 5% of normal, confirming previous indirect evidence for the storage of this protein within the alpha-granule. Dense body secretion of adenosine triphosphate and 5-hydroxytryptamine was normal. Aggregation occurred normally in response to adenosine diphosphate and there was a slight delay in response to collagen.
authors.affiliation: Department of Paediatrics, U.C. Louvain B-1200, Brussels, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Vermylen
authors.forename: J
authors.initials: J
authors.lastname: Vermylen
authors.forename: B
authors.initials: B
authors.lastname: Hoet
authors.forename: J M
authors.initials: JM
authors.lastname: Scheiff
authors.forename: J
authors.initials: J
authors.lastname: Ninane
authors.forename: G
authors.initials: G
authors.lastname: Cornu
mesh_terms: D002648:Child; D003594:Cytoplasmic Granules / Q000737:chemistry*; D004801:Eosine Yellowish-(YS); D006801:Humans; D008297:Male; D008751:Methylene Blue; D015849:Plasminogen Inactivators / Q000097:blood*; D010974:Platelet Aggregation; D010978:Platelet Factor 4 / Q000172:deficiency; D013194:Staining and Labeling; D013577:Syndrome; D013921:Thrombocytopenia / Q000378:metabolism*; D001620:beta-Thromboglobulin / Q000172:deficiency
chemical_list: C043260:May-Grunwald Giemsa; D015849:Plasminogen Inactivators; D001620:beta-Thromboglobulin; D010978:Platelet Factor 4; D008751:Methylene Blue; D004801:Eosine Yellowish-(YS)