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Primary amyloidosis
Definition
Primary amyloidosis is a disorder in which abnormal proteins build up in tissues and organs. Clumps of the abnormal proteins are called amyloid deposits.
Alternative Names
Amyloid - primary
Causes
The cause of primary amyloidosis is unknown. The condition is related to abnormal and excess production of antibodies by a type of immune cell called plasma cells.
Primary amyloidosis can lead to conditions that include:
- Carpal tunnel syndrome
- Heart muscle damage (cardiomyopathy) leading to congestive heart failure
- Intestinal malabsorption
- Liver enlargement
- Kidney failure
- Nephrotic syndrome
- Neuropathy (nerves that do not work properly)
- Orthostatic hypotension (abnormal drop in blood pressure with standing)
The deposits build up in the affected organs, causing them to become stiff, which decreases their ability to function.
Risk factors have not been identified. Primary amyloidosis is rare. It is similar to multiple myeloma, and is treated the same way.
Symptoms
Symptoms depend on the organs affected by the deposits. These organs can include the tongue, intestines, skeletal and smooth muscles, nerves, skin, ligaments, heart, liver, spleen, and kidneys.
Symptoms include:
- Abnormal heart rhythm
- Enlarged tongue
- Fatigue
- Numbness of hands and feet
- Shortness of breath
- Skin changes
- Swallowing problems
- Swelling in the arms and legs
- Weak hand grip
- Weight loss
Other symptoms that may occur with this disease:
- Decreased urine output
- Diarrhea
- Hoarseness or changing voice
- Joint pain
- Weakness
Exams and Tests
Your doctor may discover that you have an enlarged liver or spleen.
If organ damage is suspected, your doctor may order tests to confirm amyloidosis of that organ. For example:
- Abdominal ultrasound may reveal a swollen liver or spleen.
- An abdominal fat pad aspiration, rectal mucosa biopsy, or bone marrow biopsy can help confirm the diagnosis.
- A heart evaluation, including an ECG, may reveal arrhythmias, abnormal heart sounds, or signs of congestive heart failure. An echocardiogram shows poor motion of the heart wall, due to a stiff heart muscle.
- A carpal tunnel syndrome evaluation may show that hand grips are weak. Nerve conduction velocity shows abnormalities.
- Kidney function tests may show signs of kidney failure or too much protein in the urine (nephrotic syndrome).
- BUN level is increased.
- Serum creatinine is increased.
- Urinalysis shows protein, casts, or fat bodies.
This disease may also affect the results of the following tests:
- Bence-Jones protein (quantitative)
- Carpal tunnel biopsy
- Gum biopsy
- Immunoelectrophoresis - serum
- Myocardial biopsy
- Nerve biopsy
- Quantitative immunoglobulins
- Tongue biopsy
- Urine protein
Treatment
Some patients with primary amyloidosis respond to chemotherapy focused on the abnormal plasma cells. A stem cell transplant may be done, as in multiple myeloma.
In secondary amyloidosis, aggressively treating the disease that is causing the excess amyloid protein can improve symptoms and/or slow the disease from getting worse. Complications such as heart failure, kidney failure, and other problems can sometimes be treated, when needed.
Outlook (Prognosis)
How severe the disease is depends on the organs that are affected. When the heart and kidney are involved, it may lead to organ failure and death. Body-wide ( systemic) involvement can lead to death in 1 to 3 years.
Possible Complications
- Congestive heart failure
- Death
- Endocrine failure (hormonal disorder)
- Kidney failure
- Respiratory failure
When to Contact a Medical Professional
Call your health care provider if:
- You have symptoms of primary amyloidosis
- You know you have primary amyloidosis and you have difficulty breathing, persistent swelling of the ankles or other areas, decreased urine output, or other symptoms that may indicate complications have developed
Prevention
There is no known prevention for primary amyloidosis.
References
Buxbaum JN. The Amyloidoses. In: Goldman L, Ausiello D. Cecil Textbook of Medicine. 22nd ed. Philadelphia, Pa: WB Saunders; 2004.
Gertz MA, Lacy MQ, Dispenzieri A, Hayman SR. Immunoglobulin light-chain amyloidosis (primary amyloidosis). In: Hoffman R, Benz Jr. EJ, Shattil SJ, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philladelphia, Pa: Elsevier Churchill Livingston; 2008:chap 89.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
