Protein C and antithrombin levels in patients with sickle cell anemia in Ahmadu Bello University Teaching Hospital Zaria

Abstract

Background: Alterations in the components of hemostasis, namely platelet function, the procoagulant, anticoagulant, and the fibrinolytic systems, are observed in sickle cell anemia (SCA) and are in favor of a procoagulant phenotype. Therefore, study of protein C and antithrombin (AT) levels in patients with SCA in steady state may be used in the treatment and/or prevention of SCA-related thrombotic complications. We studied the changes of these naturally occurring anticoagulants in patients with SCA attending the sickle cell clinic in Ahmadu Bello University Teaching Hospital, Zaria.

Methods: We conducted a case–control study involving 50 SCA (HbSS) patients in the steady state as cases and 25 healthy volunteers with normal hemoglobin (HbAA) as controls. Protein C and AT levels were estimated by semi-automation using Diagnostica Stago hematology coagulation analyzer. Frequencies, proportions, and independent t test were performed using SPSS version 20.

Results: The mean ages of both the patients and controls were 23.80 ± 7.46 and 24.28 ± 3.48 years, respectively, and study participants comprised 40 (53.0%) women between the ages of 15–50 years and 15–34 years (P = 0.76). The mean values of protein C and AT levels in patients with SCA in the steady state and the control group were 60.26 ± 20.58% versus 81.30 ± 19.74%, 95% CI 11.13–30.96, and 42.11 ± 5.01% versus 61.88 ± 11.27%, 95% CI 16.03–23.51 with P values (P < 0.001), respectively.

Conclusions: This study showed that there was a significant decrease in the levels of protein C and AT between the SCA patients in the steady state and the controls. We recommend baseline investigations of these naturally occurring anticoagulants in patients with SCA, especially in those with frequent vaso-occlusive crises. This will give us an insight into the additional pathophysiologic mechanism in SCA-related thrombotic complications for better patient management and outcome.

Keywords: Antithrombin, hemostasis, protein C, sickle cell anemia, steady stateç