Chronic Kidney Disease amongst Sickle Cell Anaemia Patients at the University of Maiduguri Teaching Hospital, Northeastern Nigeria: A Study of Prevalence and Risk Factors.

Background: Involvement of the kidneys in patients with sickle cell anaemia is a well recognised chronic complication. This study seeks to determine the prevalence of chronic kidney disease in patients with homozygous sickle cell disease (HbSS) and to identify risk factors associated with its development.

Methodology: The subjects consisted of adolescents and adults with HbSS recruited sequentially from the adult haematology outpatient clinic and Daycare ward of the unit. Clinical variables including age at diagnosis of SCA, the frequency of vaso-occlusive crisis and transfusion therapy, as well as laboratory data including haematological profile and renal function tests were obtained. The glomerular filtration rate was estimated (eGFR) using the 'modification of diet in renal disease' (MDRD) formula.

Results: Two hundred and eighty-four HbSS patients were recruited. The prevalence of CKD amongst them was 38.9%. Further stratification of the patients based on eGFR showed that sixty-nine (26.8%) had hyperfiltration; 35 (13.6%) stage 1 CKD; 53 (20.6%) stage 2 CKD; 33 (12.8%) stage 3a CKD; 28 (10.9%) stage 3b CKD; 30 (11.7%) stage 4 CKD and 9 (3.5%) had end stage renal disease. There was significant association between eGFR and clinical parameters such as age (r -0.353, p=0.000), SBP (r -0.148, p= 0.021), DBP (r -0.213, p=0.001) and total number of blood received (r -0.276, p=0.000); and laboratory parameters such as PCV (r 0.371, p=0.000); urea ( r 0.527, p=000); creatinine (r 0.625, p=0.000) and uric acid ( r -0.419, p=0.000).

Conclusions: The present study has revealed a high prevalence of CKD amongst patients with SCA in our region. Clinical and laboratory predictors of CKD using eGFR were identified to include age, SBP, number of units of blood transfusion, PCV, urea, creatinine and uric acid levels.