title: Evaluating platelet function disorders in children with bleeding tendency - A single center study.
abstract: Platelet function disorders (PFDs) are a common cause of mild bleeding tendency. However, they cannot be recognized by standard screening studies. The gold standard test for PFD is platelet aggregation, performed by light transmission aggregometry (LTA). A newer and less validated method is the closure time (CT), performed by the platelet function Analyzer 100 (PFA-100). Data regarding the validity of these tests in children are limited. The aim of this study was to evaluate the usefulness of LTA and PFA-100 for the diagnosis of pediatric patients with bleeding tendency. This retrospective study included patients one month-18 year old that had LTA tests performed at the coagulation laboratory of Rabin Medical Center between the years 2006-2015. Bleeding severity was assessed using a pediatric bleeding score. Patients were excluded from analysis if they had thrombocytopenia, thrombocytosis or coagulation factors deficiencies. One hundred and thirty-seven (137) patients were included in the analysis. The median age was 7.5 years (range one month-18 years). Most patients (93%) had a bleeding score of 2 or more. Abnormal LTA was found in 40% and prolonged CT in 23% of the patients. Abnormal LTA was significantly more common in patients with a bleeding score of 2 or more compared to patients with a lower bleeding scores (P = 0.04). No significant correlation was found between the bleeding severity and the number of agonists which induced abnormal responses (p = 0.52) or the CT (p = 0.35). Furthermore, no correlation was found between abnormal LTA and prolonged CT. To conclude, we were able to diagnose 40% of children who presented with bleeding tendency with platelet aggregation defects by LTA. Abnormal LTA was significantly more prevalent in patients with a bleeding score of 2 and above. In contrast, CT was not found to be sensitive as a screening tool for PFD. Therefore, our data extend the validity of the use of LTA for the evaluation of pediatric patients with bleeding tendency.
authors.affiliation: a Pediatric Ward A , Haemek Medical Center , Afula , Israel.
authors.forename: Osama
authors.initials: O
authors.lastname: Tanous
authors.affiliation: b Pediatric Hematology-Oncology , Schneider Children's Medical Center of Israel , Petach Tikva , Israel.|c Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel.
authors.forename: Orna
authors.initials: O
authors.lastname: Steinberg Shemer
authors.affiliation: b Pediatric Hematology-Oncology , Schneider Children's Medical Center of Israel , Petach Tikva , Israel.|c Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel.
authors.forename: Joanne
authors.initials: J
authors.lastname: Yacobovich
authors.affiliation: b Pediatric Hematology-Oncology , Schneider Children's Medical Center of Israel , Petach Tikva , Israel.
authors.forename: Meira
authors.initials: M
authors.lastname: Zoldan
authors.affiliation: a Pediatric Ward A , Haemek Medical Center , Afula , Israel.
authors.forename: Yoseph
authors.initials: Y
authors.lastname: Horovitz
authors.affiliation: b Pediatric Hematology-Oncology , Schneider Children's Medical Center of Israel , Petach Tikva , Israel.|c Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel.
authors.forename: Isaac
authors.initials: I
authors.lastname: Yaniv
authors.affiliation: d The Coagulation Laboratory, Rabin Medical Center , Beilinson Hospital, Petach Tikva , Israel.
authors.forename: Esther
authors.initials: E
authors.lastname: Rabizadeh
authors.affiliation: b Pediatric Hematology-Oncology , Schneider Children's Medical Center of Israel , Petach Tikva , Israel.|c Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel.
authors.forename: Hannah
authors.initials: H
authors.lastname: Tamary
authors.affiliation: d The Coagulation Laboratory, Rabin Medical Center , Beilinson Hospital, Petach Tikva , Israel.
authors.forename: Sigal
authors.initials: S
authors.lastname: Nakav
authors.affiliation: d The Coagulation Laboratory, Rabin Medical Center , Beilinson Hospital, Petach Tikva , Israel.
authors.forename: Judith
authors.initials: J
authors.lastname: Lahav
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000293:Adolescent; D016718:Arachidonic Acid / Q000494:pharmacology; D057205:Automation, Laboratory; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006470:Hemorrhage / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010979:Platelet Function Tests; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D004837:Epinephrine
keywords: Bleeding disorders; PFA-100; closure time; light transmission aggregometry; pediatrics