Basic hemostatic parameters in adults with sickle cell anemia at Ahmadu Bello University Teaching Hospital, Zaria Nigeria

Abstract

Background: Reports from various studies showed that patients with sickle cell anemia (SCA) have altered components of hemostasis such as platelet function, the procoagulant, anticoagulant, and the fibrinolytic pathways. These altered components may be different or the same based on regions, racial, or environment. Determining the basic hemostatic parameters in our environment is imperative because from records this may be the first time such a study is being carried out and the altered components so involved may give an insight as to the clinical phenotypes we have in our setting. The data obtained from this study may also provide reference values appropriate for therapeutic intervention. The objective of this study is to determine some basic hemostatic parameters in patients with SCA in steady state attending the hematology clinic of Ahmadu Bello University Teaching Hospital Zaria, Nigeria. Materials and Methods: We conducted a case–control study involving fifty patients with SCA (HbSS) in steady state and 25 healthy volunteers with normal hemoglobin (HbAA) as controls between the ages of 15 and 50 years, with females comprising 40 (53.0%) and 35 (47.0%) males. Steady state refers to a point in time where a patient with SCA is not experiencing an acute painful crisis or any changes due to therapy for at least four consecutive weeks after a previous painful crisis. Platelet count was determined by hematology analyzer (Sysmex XT–2000i, Sysmex Corporation, CPO Box1002 Kobe 650–8691, Japan) while bleeding time (BT) was performed using Ivy's method, using disposable Bevel lancet with the test carried out in duplicate and superficial veins were avoided. Prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) were estimated using semi-automated coagulation analyzer. Results: The age ranges of both the patients and the controls were 15–50 years and 15–34 years with mean ages of both was 23.80 ± 7.46 and 24.28 ± 3.48 years (P = 0.76) respectively. Females comprised 53.0% of all the study participants. The mean values of hemostatic parameters in the SCA and controls groups were: Platelets (499.82 ± 208.23 vs. 230.36 ± 106.65 × 109/L, 95% confidence interval [CI]; 180.9881, 357.9319, P < 0.0001), BT (2.99 ± 0.98 vs. 2.94 ± 0.92 min, −0.4219, 0.5139, P = 0.845), PT (12.43 ± 3.11 vs. 13.18 ± 1.11 s, 95% CI; −2.0335, 0.5335, P 0.248), ±8.80 vs. 17.20 ± 5.11 s, 95% CI; 0.4874, 8.0846, P = 0.028), respectively. Conclusion: A significant increase in platelet count, TT and a significant decrease in APTT were observed in patients with SCA. These can be an evidence of hypercoagulable nature of SCA. We recommend that patients with SCA, especially those with frequent and severe vaso-occlusive crises should have these basic hemostatic tests as a baseline and during routine clinic follow-up for improved patient management.

Keywords

• Hemostasis
• sickle cell anemia
• steady state
• volunteers