Secondary systemic amyloid

Definition

Secondary systemic amyloid is a disorder in which insoluble protein fibers become deposited in tissues and organs impairing their function. It is found in association with chronic infection or chronic inflammatory disease.

Causes, incidence, and risk factors

The exact mechanism that causes secondary systemic amyloid is unknown. The risk factors include chronic inflammatory or infectious diseases. Secondary systemic amyloid occurs in association with multiple myeloma, and chronic conditions (those that last for 5 or more years) such as: rheumatoid arthritis, tuberculosis, long term paraplegia, bronchiectasis, cystic fibrosis, chronic osteomyelitis, recurrent pyogenic (involving pus) skin infection or abscess, decubitus ulcers, chronic renal dialysis, juvenile chronic arthritis, systemic lupus erythematosus, Reiter's syndrome, ankylosing spondylitis, Hodgkin's disease, Sjogren's syndrome, and hairy cell leukemia.

Symptoms are the same as in primary amyloidosis. The symptoms are related to the organs that become affected with the deposits. The affected organs exhibit reduced function.

Symptoms

• Fatigue
• Numbness of hands and feet
• Weak hand grip
• Weight loss
• Shortness of breath
• Swelling of the extremities
• Swallowing difficulties
• Irregular heart rhythm
• Bleeding in the skin
• Enlarged tongue

Signs and tests

If specific organ damage is suspected, the testing to confirm amyloidosis of that organ may include a biopsy of an affected tissue or organ that is positive for amyloid. Other tests may include: a skin biopsy of subcutaneous fat, a rectal mucosa biopsy, or a bone marrow biopsy. All of these tests are convenient, safe, and likely to be positive for confirmation of the disease.

The physical examination or abdominal ultrasound shows an enlarged liver or spleen.

Cardiac evaluation reveals arrhythmias, abnormal heart sounds, or signs of heart failure:

• ECG shows abnormalities
• Echocardiogram shows poor wall motion because of stiff heart muscle (cardiomyopathy)

Renal evaluation reveals renal failure or nephrotic syndrome(excessive protein in the urine):

• Urinalysis that shows protein, casts, or fat bodies
• Increased serum creatinine
• Increased BUN

There may also be an evaluation for carpal tunnel syndrome:

• Nerve conduction velocity that shows conduction block
• Weak hand grip associated with weakness of the thumb

Treatment

The treatment is that of the underlying condition to prevent progression of the amyloidosis. There is no specific treatment for amyloid.

Expectations (prognosis)

The severity of the disease depends upon the organs that are affected. Heart and kidney involvement may lead to organ failure and death. Systemic involvement is leads to death within 1 - 3 years.

Complications

• Heart failure
• Kidney failure
• Endocrine failure
• Respiratory failure

Calling your health care provider

Call for an appointment with your health care provider if you experience symptoms of this condition. Numbness, weak grip, shortness of breath, swelling, bleeding, and irregular heart rhythm are serious symptoms that require prompt intervention.

Prevention

There is no known primary prevention. Secondary prevention includes aggressive treatment and control of diseases known to predispose to the development of amyloid.

Illustrations

Amyloidosis on the fingers

Amyloidosis on the face

Antibodies