Renal Amyloidosis: Causes, Risk Factors, Classification, Symptoms, Diagnosis, Treatment
Kidney is a vital organ in our body and since its function is to remove waste products from our body it becomes an extremely important part of our body. Various diseases cause kidney damage resulting in malfunction of kidney. Kidney malfunction causes progressive buildup of waste products in our body resulting in various, potentially serious, medical complications. One such medical condition which affects the kidneys is Renal Amyloidosis. In this article, we will discuss about the various causes, symptoms, and treatments rendered for Renal Amyloidosis.
How Is Renal Amyloidosis Defined?
Amyloidosis is a medical disorder which is caused due to deposition of extracellular or intracellular amyloid fibrils altering normal function of tissues. When there is deposition of amyloid fibrils in the kidneys, it is then called as Renal Amyloidosis.
Causes Of Renal Amyloidosis
The potential cause of the production of amyloid and the reason for its deposition in tissues is presently not known. Potential factors are varied according to the subtype of amyloid.
Literature though suggest amyloidosis is heriditory disease.1 Renal amyloidosis associated with the R554L AFib variant has been observed in few family studies.1
Some studies suggest renal amyloidosis follows renal atherosclerosis of arterial blood vessels.
Risk Factors For Renal Amyloidosis
The major risk factor for development of Renal Amyloidosis is a family history of neuromuscular disease of unknown etiology.2
Classifications Of Amyloidosis
The Classification Of Amyloid Is Chemically Based And Is As Follows:
- A-amyloidosis: Also known as AA, this is produced in liver as a response to cytokines. This occurs in numerous inflammatory disorders like rheumatoid arthritis and systemic infections like tuberculosis, and occasionally neoplastic conditions like renal cell cancer.
- Light Chain Amyloidosis (AL): This is a monoclonal plasma cell dysfunction which is pretty much similar to multiple myeloma and produces fibril of monoclonal immunoglobulin. Organs involved with this disorder are heart, kidneys, GI tract. It was previously known as Primary Amyloidosis.
- Beta2-Microglobulin Amyloidosis: This is associated with dialysis and in rare cases Renal Failure in case if dialysis is not done.
- Hereditary Renal Amyloidosis: This is a group of medical conditions which is related to mutations in a specific protein. This condition is usually considered when a renal biopsy reveals deposition of amyloid and the tested individual has a family history of autosomal dominant diseases.
Symptoms Of Renal Amyloidosis
Some Of The Symptoms Of Renal Amyloidosis Are:
- A renal disease of unexplained etiology
- Extensive proteinuria
- Mild enlargement of kidneys
- Rarely hypertension
- Significant hepatomegaly along with renal dysfunction
- Elevated levels of alkaline phosphatase
Diagnosis of Renal Amyloidosis
If an individual experiences the above mentioned symptoms and Renal Amyloidosis is suspected, then the physician may order a renal biopsy to confirm the diagnosis of Renal Amyloidosis. Apart from the renal biopsy, the following tests can also be ordered.
- Urinalysis to look for proteinuria
- Complete blood count to look for anemia
- Creatinine levels, which will be raised in kidney dysfunction
- Liver functions to look for elevated levels of alkaline phosphatase
Treatment For Renal Amyloidosis
As of now, no treatment is available to specifically target amyloid depositions; thus, therapy is targeted towards preserving the organ function.4
In order to treat renal failure, diuretics can be used and erythropoietin is given to treat anemia. Treatment of underlying causes resulting in this condition like inflammatory conditions or carcinoma is important.
High dosage of corticosteroids has been tried in the past with moderate success.3
Liver transplantation has also shown to be effective in some subtypes of Amyloidosis; however, even then disease progression is observed. For Renal Amyloidosis, Kidney transplantation is done.
Prognosis Of Renal Amyloidosis
The prognosis for Renal Amyloidosis is unfortunately not good and people with this condition usually tend to deteriorate and end up with complications which are potentially terminal. In such cases, treatment is basically focused on comfort care and relief of pain.
1. Hereditary amyloidosis caused by R554L fibrinogen Aα-chain mutation in a Spanish family and review of the literature.
Haidinger M1, Werzowa J, Kain R, Antlanger M, Hecking M, Pfaffenberger S, Mascherbauer J, Gremmel T, Gilbertson JA, Rowczenio D, Weichhart T, Kopecky C, Hörl WH, Hawkins PN, Säemann MD.
Med Ann Dist Columbia. 1967 Apr;36(4):228-31 passim.
2. Amyloidosis: review of cardiac and renal manifestations.
Barth WF., Amyloid. 2013 Jun;20(2):72-9.
3. Update on treatment of light chain amyloidosis.
Mahmood S1, Palladini G, Sanchorawala V, Wechalekar A.
Haematologica. 2014 Feb;99(2):209-21.
4. Amyloidosis-associated kidney disease.
J Am Soc Nephrol. 2006 Dec;17(12):3458-71.