Renal Anaemia

How is CKD linked with renal anaemia?

Haemoglobin is carried by the red blood cells in the blood. Red blood cells derive from myeloid stem cells (burst-forming unit–erythroid [BFU-E] and colony-forming unit–erythroid [CFU-E] cells) in the bone marrow through the process of erythropoiesis. As a crucial first step, the hormone erythropoietin (produced by the kidney) binds to BFU-E and CFU-E cells, triggering them to divide and differentiate into ‘proerythroblasts’. After numerous stages of cell division and differentiation, haemoglobin-rich mature red blood cells are formed.

Renal anaemia can have a number of causes:

Reduced stimulation of erythropoiesis – As the kidneys become progressively damaged in CKD, they lose the ability to produce erythropoietin, leading to renal anaemia.¹
Loss of red blood cells – Patients with CKD are at risk of blood loss due to poorly functioning platelets, resulting in bleeding. One of the causes of blood loss in CKD patients is dialysis.²
Shortened red blood cell lifespan – While the average life span of a red blood cell is 120 days, this is reduced by approximately one-third in CKD patients who undergo dialysis.²

These effects contribute to iron deficiency. For example, dialysis patients may lose 3–5 g of iron per year.² Find out more about the causes of renal anaemia.

References:
1. National Institute of Diabetes and Digestive and Kidney Diseases. National Institutes of Health. Anemia in Kidney Disease and Dialysis. NIH Publication No. 05–4619.
2. Nurko S. Anemia in chronic kidney disease: causes, diagnosis, treatment. Cleve Clin J Med 2006;73:289–97.