Blood coagulation changes in patients with post-splenectomy persistent thrombocytosis

To clarify the possible role of persistent thrombocytosis after splenectomy as being a predisposing factor causing thromboembolism. Blood coagulation profiles were studied in 35 patients (20 M and 15 F, mean age 42 +/- 17.5) suffering from thrombocytosis (> 500,000/dl) who underwent splenectomy for non-malignant and non-traumatic diseases. Seventy healthy subjects acted as a control group. Tests were performed 6 months after the operation and for both groups (patients and controls) blood samples were collected for: platelets, fibrinogen, PT, APTT, AT III, plasminogen, F1 + 2, t-PA and DNA analysis for F V, F II and MTHFR. After one year all subjects were controlled for thrombocytosis, genomic abnormalities and venous thrombosis. All the analyses were performed according to the Statistical Package for Social Science. The significance of the differences in means was evaluated by non-parametric tests, differences with a P value < 0.05 being considered significant. Increased plasma levels of fibrinogen, D-dimer, F1 + 2 and PAI-1 were found in the patients compared with the control group. TPA was significantly lower in the patients than in the controls. At the one year follow-up, two patients with genetic polymorphism had suffered deep venous thrombosis. Our findings indicate that splenectomy contributes to abnormal platelet aggregation and endothelial cell activation with hypercoagulability.