title: Platelet size for distinguishing between inherited thrombocytopenias and immune thrombocytopenia: a multicentric, real life study.
abstract: The most frequent forms of inherited thrombocytopenia (IT) are characterized by platelet size abnormalities and it has been suggested that this parameter is useful for their differentiation from immune thrombocytopenia (ITP). Recently, a monocentric study identified cut-off values for mean platelet volume (MPV) and mean platelet diameter (MPD) with good diagnostic accuracy in this respect. To validate these cut-off values in a different and larger case series of patients, we enrolled 130 subjects with ITP and 113 with IT in six different centres. The platelet count and MPV was each measured by the instrument routinely used in each institution. In some centres, platelet count was also measured by optical microscopy. MPD was evaluated centrally by image analysis of peripheral blood films. The previously identified cut-off value for MPV had 91% specificity in distinguishing ITP from inherited macrothrombocytopenias (mono and biallelic Bernard-Soulier, MYH9-related disease), while its sensitivity was greatly variable depending on the instrument used. With an appropriate instrument, specificity was 83%. The diagnostic accuracy of MPD was lower than that obtained with MPV. We concluded that MPV is a useful parameter for differentiating ITP from IT provided that it is measured by appropriate cell counters.
authors.affiliation: Departments of Internal Medicine, Clinical Chemistry Laboratory, Biometry and Clinical Epidemiology Service, University of Pavia and IRCCS Policlinico San Matteo Foundation, Piazzale Golgi, Pavia, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Noris
authors.forename: Catherine
authors.initials: C
authors.lastname: Klersy
authors.forename: Paolo
authors.initials: P
authors.lastname: Gresele
authors.forename: Fiorina
authors.initials: F
authors.lastname: Giona
authors.forename: Paola
authors.initials: P
authors.lastname: Giordano
authors.forename: Pietro
authors.initials: P
authors.lastname: Minuz
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Loffredo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pecci
authors.forename: Federica
authors.initials: F
authors.lastname: Melazzini
authors.forename: Elisa
authors.initials: E
authors.lastname: Civaschi
authors.forename: Annamaria
authors.initials: A
authors.lastname: Mezzasoma
authors.forename: Monica
authors.initials: M
authors.lastname: Piedimonte
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Semeraro
authors.forename: Dino
authors.initials: D
authors.lastname: Veneri
authors.forename: Francesco
authors.initials: F
authors.lastname: Menna
authors.forename: Laura
authors.initials: L
authors.lastname: Ciardelli
authors.forename: Carlo L
authors.initials: CL
authors.lastname: Balduini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000166:cytology*; D048429:Cell Size; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood* / Q000175:diagnosis*; D012016:Reference Values; D012680:Sensitivity and Specificity; D013921:Thrombocytopenia / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics; D055815:Young Adult