title: Beyond the platelet count: immature platelet fraction and thromboelastometry correlate with bleeding in patients with immune thrombocytopenia.
abstract: Platelet counts (PC) estimate bleeding risk in Immune Thrombocytopenia (ITP). We investigated whether measures of thromboelastometry and absolute immature platelet fraction (A-IPF) would correlate better with acute bleeding score (ABS) than PC or mean platelet volume (MPV). Simultaneous determination of ABS, complete blood count and thromboelastometry was performed in 141 ITP patients; 112 underwent A-IPF testing. Subgroup analyses were performed for paediatric subjects, PC <60 × 10(9) /l and <30 × 10(9) /l. PC significantly inversely correlated with ABS in all subjects, PC <30 × 10(9) /l and total paediatric cohort. MPV did not correlate with ABS in any subgroup. Thromboelastometry measures of clot firmness, but not PC, significantly correlated with ABS in all subjects with PC <60 × 10(9) /l, and children with PC <60 × 10(9) /l and <30 × 10(9) /l. A-IPF demonstrated stronger correlation with ABS than did PC among all subjects, those with PC <60 × 10(9) /l, all children and children with PC <30 × 10(9) /l (r = -0·37; r = -0·34; r = -0·44; r = -0·60) versus ABS with PC (r = -0·36; ns; r = -0·32; ns). Stronger correlations of both thromboelastometry measures of clot firmness and A-IPF than PC with ABS suggest factors beyond PC, i.e. related to platelet function, contribute to ITP bleeding pathophysiology. Thromboelastometry, A-IPF and ABS can be incorporated into routine or acute visits.
authors.affiliation: Division of Hematology/Oncology, Department of Paediatrics, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Lindsey A
authors.initials: LA
authors.lastname: Greene
authors.forename: Siqi
authors.initials: S
authors.lastname: Chen
authors.forename: Caroline
authors.initials: C
authors.lastname: Seery
authors.forename: Allison M
authors.initials: AM
authors.lastname: Imahiyerobo
authors.forename: James B
authors.initials: JB
authors.lastname: Bussel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006470:Hemorrhage / Q000097:blood / Q000209:etiology*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010976:Platelet Count / Q000379:methods; D011446:Prospective Studies; D013916:Thrombelastography / Q000379:methods; D013921:Thrombocytopenia / Q000097:blood / Q000150:complications*; D055815:Young Adult
keywords: immature platelet fraction; immune thrombocytopenia (ITP); paediatric; platelet; thromboelastometry