Lipoid Nephrosis

Lipoid nephrosis is also called Minimal Lesion Disease or Childhood Nephrotic Syndrome.

·        It is called Minimal Lesion Disease because the glomeruli look normal histologically.

·        It is called Childhood Nephrotic Syndrome because primary lipoid nephrosis is most common in children, with a peak incidence at 2-3 years of age. The cause is idiopathic, a disease without any underlying problems. ***super-important*** to remember!!! 

Although primary lipoid nephrosis has the highest prevalence, secondary lipoid nephrosis also exists. Secondary lipoid nephrosis is more common in adults, and is due to drugs (NSAIDS, etc.), allergies, and neoplasia.

Clinical Presentation

·        Massive proteinuria (selective for albumin)

o        Other nephrotic diseases do not excrete pure albumin in the urine, so this is ***super-important*** to remember!
 

·        Hyperlipidemia

·        Hypoproteinemia

 Laboratory Findings

·        Large, pale kidneys

o        The hyperlipidemic state causes lipid deposition within the kidneys and basement membrane.

·        Protein inclusions in tubular epithelium

o        This is the site of protein reabsorption back into the blood.

·        Light microscopy – Normal-appearing glomeruli

·        Electron microscopy – Normal basement membrane but fusion of podocytes

o        Fusion of foot processes occurs in all glomerulonephritis diseases that cause proteinuria.

o        This is diagnostic 

o        The top picture shows the fusion of podocytes.

o        The bottom picture shows normal podocytes.

Treatment

·        Corticosteroids

o        Lipoid nephrotic kidneys are extremely sensitive to corticosteroid therapy. They close the inter-epithelial gaps that are hypothesized to cause the proteinuria and so resolve this problem in 60-80% of all cases.

o        This is a ***super-important*** fact to remember!!!

·        For those patients who are resistant to corticosteroids, there will be a change in the disease. Lipoid nephrosis would not have been treated, and the disease will progress to Focal Segmental Glomerulonephritis.

Complications

·        Patients are more prone to infections because of the loss of antibodies in their urine.

o        ***super-important*** fact to remember!!!

o        Also, the use of corticosteroids increases the risk of infection.

·        Premature atherosclerosis

o        The hyperlipidemic condition of the patient can cause premature atherosclerosis. Teenagers can die of MIs if lipoid nephrosis is not appropriately treated and managed.

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