Amyloid nephropathy (amyloidosis kidney disease)

• What is Amyloid Nephropathy (Amyloidosis)
• Statistics on Amyloid Nephropathy (Amyloidosis)
• Risk Factors for Amyloid Nephropathy (Amyloidosis)
• Progression of Amyloid Nephropathy (Amyloidosis)
• Symptoms of Amyloid Nephropathy (Amyloidosis)
• Clinical Examination of Amyloid Nephropathy (Amyloidosis)
• How is Amyloid Nephropathy (Amyloidosis) Diagnosed?
• Prognosis of Amyloid Nephropathy (Amyloidosis)
• How is Amyloid Nephropathy (Amyloidosis) Treated?
• Amyloid Nephropathy (Amyloidosis) References

What is Amyloid Nephropathy (Amyloidosis)

Amyloidosis is a systemic disease that may affect the glomeruli of the kidneys. Amyloidosis itself is a disorder of protein metabolism characterised by the widespread deposition of abnormal protein strands throughout multiple organ systems of the body. The kidneys are commonly affected by this disorder.

Statistics on Amyloid Nephropathy (Amyloidosis)

Amyloidosis can be classified as either inherited or secondary to another disease process. Clinically significant amyloidosis is not rare, and is a common feature of a number of diseases such as Alzheimer’s disease and rheumatoid arthritis.

The incidence of amyloid nephropathy varies with the condition of origin. Amyloid nephropathy is also more common in patients suffering amyloid nephropathy.

Risk Factors for Amyloid Nephropathy (Amyloidosis)

The most important predisposing factor for the development of lupus nephritis is the presence of systemic amyloidosis. This may occur as a hereditary amyloid disorder or more ferquently secondary to another medical condition such as certain infections, certain forms of cancer and long-term dialysis therapy for renal failure. A family history of amyloid disease is therefore an important risk factor of disease.

The presence of conditions causing secondary amyloidosis is also a predisposing factor for amyloid nephritis. These include:

• Multiple myeloma and other malignancies;
• Long-term infections such as tuberculosis, osteomyelitis and leprosy;
• Long-term inflammatory disorders such as rheumatoid arthritis.

Progression of Amyloid Nephropathy (Amyloidosis)

The onset of amyloid nephropathy features the loss of protein on the urine, as the function of the kidneys begins to deteriorate. The condition will usually progress, with an increase in the amount of protein lost in the urine prior to the development of renal failure.

How is Amyloid Nephropathy (Amyloidosis) Diagnosed?

The diagnosis of amyloid nephropathy is usually made on exclusion of other important different diagnoses. These include conditions such as glomerulonephritis and autoimmune disease. A number of blood tests and urines samples may be required to adequately exclude these conditions.

Prognosis of Amyloid Nephropathy (Amyloidosis)

The prognosis of amyloid nephropathy is not pleasing. The majority of patients will eventually develop renal failure, the rate of which defined by the type and severity of disease as well as the effectiveness of treatment. The prognosis of this condition should also consider the effect of amyloidosis on other organ systems such as the brain, spleen and liver.

How is Amyloid Nephropathy (Amyloidosis) Treated?

The treatment of this condition can be divided into specific treatment and supportive treatment.

• Specific treatment: Depends on the type of amyloidosis present:
  • AL amyloidosis (related to multiple myeloma) – Chemotherapy against multiple myeloma
  • AA amyloidosis (related to long-term infection and inflammation) – Treatment of the inflammation or infection that is inducing the amyloidosis.
• Supportive therapy: Provide appropriate support for nephrotic syndrome and renal failure as outlined in their respective sections. Patients with end-stage renal failure are candidates for dialysis and kidney transplantation.

Amyloid Nephropathy (Amyloidosis) References

1. Braunwald E, Fauci AS, Kasper DL, et al. Harrison’s Principles of Internal Medicine (15th edition). New York: McGraw-Hill Publishing; 2001. Book
2. Cotran RS, Kumar V, Collins T, Robbins SL. Robbins Pathologic Basis of Disease (6th edition). Philadelphia: WB Saunders Company; 1999. Book
3. Longmore M, Wilkinson I, Torok E. Oxford Handbook of Clinical Medicine (5th edition). Oxford: Oxford University Press; 2001. Book