Sickle cell anaemia (SCA) is characterized by sickled red blood cells which cause micro-infarct formation, ischaemia, decreased medullary blood flow and papillary necrosis. Sickle red blood cells have been reported to have a lower than normal membrane sialic acid content resulting in an abnormal interaction between sickle red blood cells and the microvascular endothelium. This deficiency is possibly reflected in a commensurate removal of the compound from the circulation. This study was designed to assess serum sialic acid (SSA) in SCA patients and its relationship with some anthropometric variables in SCA patients. This was achieved by determining the level of sialic acid in the serum of these patients. A total of 68 asymptomatic SCA patients and 30 non sickle cell anaemia controls were used for the study.
Results obtained showed that the SCA patients had a significantly (P < 0.05) lower BMI (20.85 ± 0.68kg/m2), higher WHR (0.89 ± 0.01) and lower sBP (111.6 ± 1.97mmHg) than the control subjects with mean BMI of 24.63 ± 0.68 kg/m2, WHR 0.86 ± 0.01, and SBP 116.0 ± 1.86 mmHg. There was a significantly (P < 0.05) elevated plasma urea (6.43 ± 0.54mmol/L) and the serum sialic acid (1.88mmol/L) was significantly (P < 0.05) lower in the SCA patients than in the control with a plasma urea of 3.33 ± 0.16mmol/L, and SSA of 1.93 ± 0.67mmol/L. SSA was also found to be significantly (P < 0.05) higher in females (1.93 ± 0.09mmol/L) than in males (1.80 ± 0.09mmol/L).
There was a negative correlation between SSA and dBP (r = - 0.03, P> 0.05) while a positive correlation was found between SSA and sBP (r = 0.05, P >0.05), BMI (r = 0.04, P > 0.05), WHR (r = 0.11, P > 0.05) and plasma creatinine (r = 0.17, P > 0.05). A significant positive correlation was found between SSA and plasma urea (r = 0.27, P< 0.05) in the SCA patients. Serum sialic acid was lower in SCA patients and it is clinically correlated with WHR, BMI, and blood pressure which are prognostic factors for cardiovascular disease. SSA is also clinically correlated with plasma urea and creatinine. SSA can therefore be used as a predictor of cardiovascular and renal complications in SCA.