Serum levels of copeptin, C-reactive protein and cortisol in different severity groups of sickle cell anaemia.

It is well known that individuals with SCA undergo constant physiological stress even, in steady state. However, there is little information on the relationship between the severity of sickle cell anaemia (SCA) and serum levels of biomarkers of stress. This study therefore determined the serum levels of copeptin, cortisol and CRP in adults with SCA in different severity groups. Sixty adults with sickle cell anaemia in steady state (27.1±6.3 years) and in vaso-occlusive crisis (24.9±4.9 years) were recruited into this cross-sectional study. Degree of severity (mild, moderate or severe) was determined using a scoring system incorporating annual number of blood transfusions, crisis and presence of anaemia, vaso-occlusive pain and organ complications. Standard methods were used for the determination of packed cell volume (PCV), total white blood cell count (WBC), blood pressure measurements and anthropometric indices. Serum levels of copeptin, cortisol and CRP were determined using ELISA with the ratios calculated accordingly. Data obtained were statistically analyzed using the Student's t-test, Mann Whitney U and Chi-square test as appropriate. P<0.05 was considered significant. The mean systolic blood pressure (SBP) and copeptin level were significantly higher in subjects with moderate SCA compared with those with mild SCA. Similarly SBP, pulse, WBC, copeptin and cortisol were significantly higher while body weight was significantly lower in subjects with severe SCA compared with subjects with mild SCA. However, WBC and cortisol-to-copeptin ratio were significantly higher in subjects with severe SCA compared with subjects with moderate SCA. There was progressive rise in serum levels of CRP from mild SCA through severe SCA but the differences were not statistically significant. Also, proportions of subjects with elevated SBP and WBC were higher than the proportion of subjects with lower SBP and WBC in the severe SCA group. Serum levels of cortisol, copeptin, and their ratio could differentiate severe SCA from mild or moderate SCA. Also, elevated systolic blood pressure and total white blood cell count are associated with severe sickle cell anaemia.