Assessment of renal status in sickle cell anaemia patients using serum cystatin C and urine microalbumin

Abstract

Background: Sickle cell disease is a group of haemoglobin disorders with the homozygous form being the commonest. Renal manifestations are varied, and include both structural and functional abnormalities. The aim of this study is to compare the usefulness of the traditional markers of renal functions in SCD patients (urea and creatinine) with more sensitive markers (Cystatin C and Microalbumin).

Methods: This was a case-control study involving 80 participants consisting of 40 subjects with sickle cell anaemia and 40 HbAA controls. 5mls of blood was collected from subjects and HbAA controls into lithium heparin gel tubes and centrifuged to obtain plasma. This was used for urea, creatinine and cystatin C analyses. cystatin C analysis was done using the ELISA method. 10mls of fresh early morning urine was collected in cryotubes. This was used for urine microalbumin estimation. Urea, creatinine and microalbumin analysis were done using the Roche/Hitachi 902 Autoanalyzer

Results: The mean plasma urea and creatinine levels were significantly lower in the study group (2.40+1.60mmol/l; 64.50+16.4umol/L) compared with the control group (2.60+0.81mmol/l; 84.9+29.1um/L). In both cases, p=0.001.

Conversely, the mean urine microalbumin and plasma cystatin C levels were higher in the study population (37.00+65.9mg/L; 1149.90+311.4ng/ml) compared with the control group (5.90+5.20mg/L; 1033.2+368.3ng/ml). p=0.140.

Conclusion: Mean urine microalbuminn and plasma cystatin C levels were higher in study population than control unlike the mean plasma creatinine and urea levels..

Keywords: Sickle cell anaemia, renal disease, Microalbumin, cystatin c