Sickle Cell Disease-Induced Chronic Kidney Disease

Sickle Cell Disease (SCD), also simply called sickle cell, is a group of inherited haemoglobin-related blood disorders. The most common type is known as sickle cell anaemia. This results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads in turn to the red blood cells adopting an abnormal sickle-like shape under certain circumstances. With this shape, they are unable to deform as they pass through capillaries, causing blockages, which really hurts.

People with this mutation are (relatively) protected against the danger of dying of malaria[1].

Sickle Cell Disease causes several negative kidney manifestations. These include defects in urine concentration, impaired handling of potassium and hydrogen ion, albuminuria, acute kidney injury, and Chronic Kidney Disease just to name a few[2].

Glomerular hyperfiltration, tubular hyperfunctioning, endothelial damage from repeated sickling and vaso-occlusive episodes, and iron-induced proinflammatory changes in the glomerular mesangium and tubulointerstitium are some of the mechanisms of kidney damage.

Albuminuria is one of the most and common clinical features of kidney disease and progresses with age. Kidney disease in patients with sickle cell is also associated with increased mortality.

Adequate hydration, angiotensin-converting enzyme inhibitors, and adequate control of sickle cell are the main stay of treatment for albuminuria. The haemoglobin goal for patients with sickle cell nephropathy is lesser (10 g/dL) than that for patients with Chronic Kidney Disease due to other causes, given that a higher haemoglobin level increases viscosity and the risk of precipitating vaso-occlusive episodes.

Also, recurrent episodes of vaso-occlusion and inflammation will result in progressive damage to most organs, including the brain, kidneys, lungs, bones, and cardiovascular system, which becomes apparent with increasing age[3].

We propose to call this Chronic Kidney Disease of non-Traditional causes (CKDnT): Sickle Cell Disease-Induced Chronic Kidney Disease.

[1] Luzzatto: Sickle Cell Anaemia and Malaria in Mediterranean Journal of Hematology and Infectious Diseases - 2012
[2] Amarapurkar et al: Sickle Cell Disease and Kidney in Advances in Chronic Kidney Disease – 2022
[3] Rees: Sickle-cell disease in The Lancet - 2010