A STUDY OF  HAEMOSTATIC ABNORMALITIES IN PATIENTS ATTENDING THE SICKLE CELL CLINIC IN ABUTH, ZARIA

USMAN KUSFA IBRAHIM

USMAN KUSFA IBRAHIM National Postgrduate Medical College of Nigeria (NPMCN)

Abstract

Sickle cell haemoglobinopathies are life-long inheritable conditions resulting from the inheritance of the sickle haemoglobin (HbS) gene from both parents. Sickle cell disorders are prone to haemostatic anomalies linked to erythrocyte sickling consequent on hypoxic precipitation of Hb S. These haemostatic changes result from increased adherence of irreversibly sickled cells to the vascular endothelium, intravascular haemolysis, endothelial denudation, consumption of nitric oxide; activation of platelets together with the procoagulant proteins, reactive fibrinolysis and altered vascular patency. Organ dysfunction and clinical outcome in HbS individuals may be determined by haemostatic changes. The dearth of information linking haemostatic changes to clinical outcomes prompted this study.
Seventy-five participants were recruited into the study. They comprised of 50 as the subjects (HbS) group, and 25 apparently healthy individuals (HbA) as the control group. The subjects group was made up of 33 females and 17 males, while the control group was made up of 7 females and 18 males. A structured questionnaire was administered to each consenting participant to obtain demographic data and information. Also 9.5mls of venous blood samples were collected, 5mls of which were placed in EDTA bottles for full blood count and haemoglobin electrophoresis, while 4.5mls were collected into a test bottle containing 0.5mls of 3.2% Sodium citrate for prothrombin time (PT) test, activated partial thromboplastin time (APTT) test, thrombin time (TT) test, D-dimer assay, protein C assay and antithrombin (AT) estimation. bleeding time (BT) was done by Ivy’s method.
The mean ages of the subjects and control groups were 23.80 ± 7.46 years and 24.28 ± 3.48 years (p = 0.649) respectively. The mean WBC (10.74 ± 3.18 vs 6.02 ± 1.6x109/l ), the mean platelet count (499.82 ± 208.23 vs 230.36 ± 106.65x109/l), the mean reticulocyte count (9.23 ± 4.37 vs 2.03 ± 1.08%), the mean reticulocyte index (2.49 ± 1.18 vs 1.63 ± 0.54), the mean MCV (85.18 ± 7.34 vs 84.4fl), the mean MCH (30.11 ± 3.13 vs 28.57 ± 1.39 pg) and the mean MCHC (35.33 ± 2.08 vs 33.58 ± 1.52g/dl) were significantly higher in the subjects than the controls (p= < 0.0001) respectively except for MCV (p= 0.908). The mean Hb (8.49 ± 1.23 vs 13.41± 1.52g/dl) was found to be lower in the subjects than the controls with statistically significant difference (p= < 0.0001). The mean PT (12.43 ± 3.11 vs 13.18 ± 1.11sec) and the mean APTT (30.32 ± 4.50 vs 33.76 ± 3.67sec) were shorter in the subjects than the control with statistically significant difference only in APTT (p= < 0.0001).
The mean TT (21.48 ±8.80 vs 17.20 ± 5.11sec) was longer in the subjects than the control with statistically significant difference (p= 0.028). There was no significant difference in the BT of the two groups (p= 0.845).The mean D-dimer (2871.13 ± 2764.95 vs 795.32 ± 1290.22 ng/ml) was significantly elevated in the subjects than the control (p= < 0.0001), the mean protein C (60.26 ± 20.58 vs 81.30 ± 19.74%), the mean AT (42.11 ± 5.01 vs 61.88 ± 27%) were significantly lower in the subjects than the control (p= < 0.0001) respectively.
This study demonstrated that there was activation of both coagulation and fibrinolytic systems as shown by reduced levels of both protein C and antithrombin and the elevation of D-dimer levels in the subjects more than the control group with statistically significant difference (p= < 0.0001) respectively.
Therefore, broad- based studies are required to adequately answer the question or establish the role of coagulation assays in the prediction of crises and monitoring of individuals with SCD.