Study of platelet activation, hypercoagulable state, and the association with pulmonary hypertension in children with β-thalassemia.

BACKGROUND

The increased survival rate of thalassemic patients has led to unmasking of management related complications which were infrequently encountered.

OBJECTIVE

Study the increased coagulation and platelet activation in children with β-thalassemia, to analyze the factors that lead to such hypercoagulable state and to study pulmonary hypertension (PH) in conjunction with platelet activation and hypercoagulable state in children with β-thalassemia.

METHODS

36 Egyptian children with β-thalassemia with a mean age of 9.9years (±4.7 SD). In addition, 20 healthy Egyptian children matched for age and sex were enrolled as a control group. Both were subjected to clinical and laboratory assessments. Echocardiography was done to the patient group and PH was diagnosed based on calculated mean pulmonary artery pressure [MPAP] >25mmHg.

RESULTS

We found that, mean±SD serum P-selectin level (platelet activator marker) was significantly higher in thalassemic patients (2337±566pg/ml) in comparison to controls (1467±247pg/ml) (P<0.001). Mean serum protein-C and antithrombin-III levels were significantly lower in thalassemic patients (1.2±1.3µg/ml, 27.3±7.5mg/dl) in comparison to controls (2.3±1.3µg/ml, 35.1±4.1mg/dl) (P=0.003 and <0.001) respectively. PH was detected in 17 (47.2%) patients and it was significantly associated with splenectomy (P=0.01) and non-transfusion dependent thalassemia (NTDT) (P=0.04). PH was positively correlated with serum levels of P-selectin (r=0.38, P=0.02), fibrinogen (r=0.41, P=0.01) and negatively correlated with serum protein-C level (r=-0.48, P=0.003).

CONCLUSION

A chronic hypercoagulable state and platelet activation is present in children with β-thalassemia. Splenectomy and transfusion infrequency are the main risk factors noted to be associated with such hypercoagulable state and platelet activation and consequently the PH among our thalassemic patients.