Sickle Cell Nephropathy Sickle cell disease (SCD) is an autosomal recessive hemoglobinopathy caused by a point mutation in the β-globin chain of haemoglobin, causing the amino acid glutamic acid to be replaced with the hydrophobic amino acid valine at the sixth position. The β-globin gene is found on the short arm of chromosome 11
Autosomal recessive
Sickle cell distribution
Post infectious glomerulonephritis (IGN) Chronic glomerulonhephritis,Focal segmental glomerulosclerosis (FSGS) and Membranous glomerulopathy Chronic tubulointerstitial nephropathy (CTIN)
A retrospective study cohort in king fahad hospital in KSA 2004 among 203 pt (11 with SCD, and 192 with ESRD due to diverse etiologies showed The median survival of patient with SCD becomes only four year from the time of diagnosis of CRF is made
Renal replacement therapy – from the hem- dialysis and renal transplant shows High incidence of HBV HCV antibodies Higher request of blood transfusion Higher mortality rate Death occur in younger ages since the commencement of HD
Another studies done in 1- King Khalid University Hospital, Riyadh, Saudi Arabia 73 patient with SCD shows
Renal and urinary abnormalities in the study patients VariablePatient number (%) BUN2 (2.7) BUN9 (12) S, creatinine2 (2.7) S. creatinine28 (38) Creatinine clearance12 (22.5) Proteinuria30 (41) Hematuria7(8.5) Hemoglobinuria12 (14,5) BUN=Blood urea nitrogen, S=Serum
Renal abnormalities in SCD Various forms of renal abnormalities have been observed in SCD patients. impaired urinary concentrating ability defects of urinary acidification defects of potassium excretion defects of glomerular hyper filtration in children
progressive decrease in glomerular filtration rate with advancing age. Recurrent hematuria. Proteinuria. renal papillary necrosis. Progressive renal Impairment with end-stage renal disease (ESRD) are all.
Pathogenesis The rate of oxygen consumption by the kidney is very high rendering it particularly susceptible to hypoxia caused by vase-occlusion. The renal medulla favors red cell sickling due to presence of hypertonic environment and acidosis leading to hypoxic damage
Research evidence suggests that prolonged glomerular hyperfiltration due to any cause, including SCD during childhood, leads to glomerular damage resulting in glomerular sclerosis, proteinuria and progressive renal failure.
Hematuria has been described as one of the most common abnormalities, not only in homozygous SCD but also in sickle cell trait. Hematuria is usually a result of red cell sickling in the renal medulla. In some cases, it may result from papillary necrosis
Summary renal abnormalities, particularly proteinuria, are common in adolescent and adult patients with SCD. As proteinuria is a risk factor for developing renal impairment in future, these patients should be actively monitored and those who develop proteinuria, should be considered for early intervention.