A study of antithrombin 111 in sickle cell anaemia patients in steady state and during vaso-0cclusive crisis in North-Eastern Nigeria.

Sickle cell anaemia (SCA) is a genetic disorder which can be complicated by haemolytic, vasoocclusive and thrombotic processes. Antithrombin III (ATIII) is a naturally occurring anticoagulant with anti inflammatory properties. The objective of this study was to determine the level of ATIII in individuals with SCA and to assess its role in vaso-occlusive crisis. This was an observational cross sectional study in which 60 adult HbSS (34 in steady state and 26 in vaso-occlusive crisis) subjects and 60 apparently healthy adults matched for sex and age served as controls. Haemoglobin (Hb) electrophoresis of subjects and controls was determined using Hb electrophoresis. Nine and a half (9.5) milliliters of blood, divided into two aliquots of 4.5mls (in 0.5mls of tri sodium citrate for coagulation studies) and 5mls (in EDTA containing bottle for full blood count) was obtained. Quantitative assessment of antithrombin III by chromogenic assay with Factor Xa was carried out using Diachrom ATIII test kit. Prothrombin time(PT), activated partial thromboplastin time(APTT), haematocrit, total white blood cells (WBC) and platelets count were assessed using standard protocol. SPSS (version 13 for windows) was used for data analysis. A p value of <0.05 was considered significant. The subjects were made up of 33(55%) males and 27(45%) females, with a mean age of 22.52(5.21) years whilst the controls consisted of 34(56.7%) males and 26(43.3%) females with a mean age of 22.85 (4.20). HbS subjects had a significantly lower ATIII levels compared with controls (p=0.009). Levels of ATIII that was found in SCA patients in steady state and in vaso-occlusive crisis did not differ significantly (p=0.468). Haematocrit was significantly lower in HbS than controls (p=0.000), whereas total WBC count (p=0.000), absolute platelet count (p=0.003), and Prothrombin time (0.008) were significantly higher in the HbS subjects. ATIII levels did not differ significantly between steady state and vasoocclusive crisis, suggesting that ATIII does not play an active role in pathogenesis of vasoocclusive crisis.