Background: Thrombocytopathy, or abnormal platelet function, is a common cause for bleeding tendency. However, it cannot be recognized by standard studies. The gold standard test for thrombocytopathy is platelet aggregation studies, performed by light transmission aggregometry (LTA). A newer and less validated method is closure time (CT), performed by the Platelet Function Analyzer 100 (PFA-100).
Patients and Methods: This retrospective study included patients 0-18 year old that had LTA tests performed in the coagulation laboratory in the 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 deficiency.
Results: Overall, we evaluated 164 charts, 137 patients were included in the analysis. The median age was 7.5 years (range 0-18). Most patients had a moderate bleeding score of 2 (48%) or 3 (31%) and only 13% had a high bleeding score of 4. Cutaneous bleeding was significantly more common in girls as compared to boys (p=0.001). Abnormal LTA was found in 40% and prolonged CT in 23% of the patients. No significant correlation was found between the bleeding severity and the existence of pathological LTA (p=0.86), the number of impaired agonists (p=0.65) or the CT (p=0.35). A concordance between the number of impaired agonists and CT was found only in patients with bleeding scores of 3 and 4 (p=0.001).
Conclusion: Although LTA remains the gold standard for the evaluation of platelet function, no clear correlation was found between the impairment of platelet function and the bleeding severity in pediatric patients.
