Natural coagulation inhibitors (protein C, protein S, antithrombin) in patients with sickle cell anemia in a steady state

PubMedID: 11737735Background: Patients with sickle cell anemia (SCA) run the risk of having decreased levels of natural coagulation inhibitors. This may be due to either hemostatic abnormalities or hepatic dysfunction. This study is designed to evaluate coagulation profiles of patients with SCA in a steady state and to determine whether hypercoagulable state is present or not. Methods: Seventeen children with SCA in a steady state were included in this study. The routine hematological evaluation was done with a coulter-counter. Reticulocyte percentage and blood coagulation tests were also determined. The coagulation inhibitors such as protein C (as activated partial thromboplastine time prolongation time), protein S (as Factor V inhibition) and antithrombin (colorimetric assay) were measured in all cases. Results: In the coagulation profile, mean euglobuline lysis time and mean fibrin degradation product levels were both significantly higher in the patient group than in the control group (P < 0.05), although other parameters were within normal limits. The values for aspartate aminotransferase (AST), alanine aminotransferase (ALT) and indirect reacting bilirubin were significantly higher in the patient group than in the control group (P < 0.001, P < 0.005, P < 0.0001, respectively). The serum protein levels were normal. Mean factor V level was significantly lower and mean factor VIII level was found significantly higher in the patient group than in the control group (P < 0.05 and P < 0.005, respectively). Protein C and AT levels were lower in patients with SCA than in control subjects (P < 0.001). Protein S levels were also lower in the patient group than in the control group, but the difference between the two groups was not significant (P < 0.05). Conclusion: It is indicated that antithrombotic functions of patients with SCA are handicapped even in a steady state; and both hemostatic abnormalities and hepatic dysfunction contribute to low levels of natural coagulation inhibitors