title: [Pseudothrombocytopenia: incidence, causes and methods of detection].
abstract: A prospective study of 20,761 routine clinical blood specimens was conducted in order to evaluate incidence and causes of pseudothrombocytopenia. All specimens were drawn in outpatient regimen and were analyzed by using the Coulter STKR autoanalyzer. The incidence of pseudothrombocytopenia was 0.15%, values clearly lower than others previously reported in hospitalized patients (1.9%). Of these patients, 72% had EDTA-induced platelet clumping sometimes associated to sodium citrate and 28% had spurious low platelet counts due to large platelets. No other causes of pseudothrombocytopenia were appreciated. It is important to remark that 49% of low platelet counts detected by the Coulter STKR have been due to pseudothrombocytopenia, and this instrument showed normal platelet and leukocyte histogram in 10% of these cases. Although time consuming these results confirm the necessity of preparation and examination of all blood smears presenting thrombocytopenia by automated cell-counting despite normal histograms. This approach would avoid erroneous diagnosis and dangerous medical or surgical therapy. A correlation of pseudothrombocytopenia with age, sex or clinical diagnosis were not found.
authors.affiliation: Servicio de Hematología y Hemoterapia, Hospital Príncipe de Asturias, Universidad de Alcalá de Henares.
authors.forename: J
authors.initials: J
authors.lastname: García Suárez
authors.forename: J L
authors.initials: JL
authors.lastname: Merino
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez
authors.forename: A
authors.initials: A
authors.lastname: Velasco
authors.forename: M C
authors.initials: MC
authors.lastname: Moreno
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001792:Blood Platelets / Q000187:drug effects / Q000648:ultrastructure; D002648:Child; D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D004492:Edetic Acid / Q000494:pharmacology; D005189:False Positive Reactions; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count / Q000295:instrumentation / Q000379:methods; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000097:blood* / Q000453:epidemiology
chemical_list: D002951:Citrates; D019343:Citric Acid; D004492:Edetic Acid
vernacular_title: Pseudotrombocitopenia: incidencia, causas y métodos de detección.