Oedemas and proteinuria: amyloid nephropathy

Renal damage is a common complication of AL amyloidosis. It is caused by deposits of abnormal proteins produced by the kidneys. The type of renal damage differs depending on where the deposits are located (in the glomerulus or the ureter). Damage to the glomerulus is the most common and means that kidneys can no longer filter properly, leading to a ‘protein drain’ in the urine. This is called ‘nephrotic syndrome’ and is present in a range of renal diseases. Nephrotic syndrome is characterised by raised levels of proteinuria and hypoalbuminemia.  It presents with 3 symptoms: oedemas, significant levels of proteinuria (i.e. more than 3 grams of urinary proteins lost per day) and hypoproteinaemia (low concentration of proteins in the blood, less than 60 grams per litre, given that normal concentration levels are 65g/l). Measuring the amount of proteins (albumin) in the blood and the urine is used to detect amyloid renal damage. Diagnosis often requires a renal biopsy.

Video: The nephrological approach, Dr REMY, nephrologist