Determinants of platelet count in pediatric patients with congenital cyanotic heart disease: Role of immature platelet fraction.

OBJECTIVES

Congenital heart defects are common noninfectious causes of mortality in children. Bleeding and thrombosis are both limiting factors in the management of such patients. We assessed the frequency of thrombocytopenia in pediatric patients with congenital cyanotic heart disease (CCHD) and evaluated determinants of platelet count including immature platelet fraction (IPF) and their role in the pathogenesis of thrombocytopenia.

METHODS

Forty-six children and adolescents with CCHD during pre-catheter visits were studied; median age was 20.5 months. Complete blood count including IPF as a marker of platelet production and reticulated hemoglobin content (RET-He) as a marker of red cell production and iron status were done on Sysmex XE 2100 (Sysmex, Japan). C-reactive protein, prothrombin time (PT), Activated partial thromboplastin time (APTT) were also assessed.

RESULTS

Thrombocytopenia was found in 6 patients (13%). PT was prolonged (P = .016) and IPF was significantly higher in patients with thrombocytopenia compared with patients with normal platelet count (14.15 ± 5.2% vs 6.68 ± 3.39%; P = .003). Platelet count was negatively correlated with IPF while significant positive correlations were found between IPF and hemoglobin, red blood cells (RBCs) count, hematocrit (Hct), PT, reticulocytes count, and immature reticulocyte fraction.

CONCLUSIONS

We suggest that elevated IPF in CCHD patients with thrombocytopenia may denote peripheral platelets destruction as an underlying mechanism. Hemoglobin level, RBCs count, Hct, and RET-He were not significant determinants for platelet count in CCHD.