Minimal change disease | |
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The three hallmarks of minimal change disease: diffuse loss of podocyte foot processes, vacuolation, and the appearance of microvilli. | |
Classification and external resources | |
Specialty | urology |
ICD-10 | N00-N08 with .0 suffix |
ICD-9-CM | 581.3 |
DiseasesDB | 8230 |
MedlinePlus | 000496 |
eMedicine | med/1483 |
Minimal change disease (also known as MCD and nil disease, among others) is a disease affecting the kidneys which causes a nephrotic syndrome. Nephrotic syndrome leads to the excretion of protein, which causes the widespread oedema (soft tissue swelling) and impaired kidney function commonly experienced by those affected by the disease. It is most common in children and has a peak incidence at 2 to 3 years of age
The clinical signs of minimal change disease are proteinuria (abnormal excretion of proteins, mainly albumin, into the urine), edema (swelling of soft tissues as a consequence of water retention), and hypoalbuminaemia (low serum albumin). These signs are referred to collectively as nephrotic syndrome. Minimal change disease is unique among the causes of nephrotic syndrome as it lacks evidence of pathology in light microscopy, hence the name.
When albumin is excreted in the urine, its serum (blood) concentration decreases. Consequently, the intravascular oncotic pressure reduces relative to the interstitial tissue. The subsequent movement of fluid from the vascular compartment to the interstitial compartment manifests as the soft tissue swelling referred to as edema. This fluid collects most commonly in the feet and legs, in response to gravity, particularly in those with poorly functioning valves. In severe cases, fluid can shift into the peritoneal cavity (abdomen) and cause ascites. As a result of the excess fluid, individuals with minimal change disease often gain weight, as they are excreting less water in the urine, and experience fatigue. Additionally, the protein in the urine causes it to become frothy.