Primary amyloidosis is a disorder in which protein fibers are deposited in tissues and organs, harming them.

The cause of primary amyloidosis is unknown, but the condition is related to abnormal production of antibodies by a type of immune cell called plasma cells.

The 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.

Primary amyloidosis can result in conditions that include:

• Cardiomyopathy
• Carpal tunnel syndrome
• Gastrointestinal reflux (GERD)
• Kidney failure
• Malabsorption

The deposits invade the affected organs, causing them to become stiff, which decreases their ability to function. Secondary amyloidosis can be caused by infection, inflammatory diseases, and sometimes cancer.

Risk factors have not been identified. Primary amyloidosis is rare. It is related to the malignant plasma cell disorder multiple myeloma.

• Enlarged tongue
• Fatigue
• Irregular heart rhythm
• Numbness of hands and feet
• Shortness of breath
• Skin changes
• Swallowing difficulties
• Swelling in the arms and legs
• Weak hand grip
• Weight loss

Additional symptoms that may be associated with this disease:

• Clay-colored stools
• Decreased urine output
• Diarrhea
• Hoarseness or changing voice
• Joint pain
• Other tongue problems
• Weakness

Your doctor may discover that you have an enlarged liver or spleen. You may also have signs of heart failure.

If specific organ damage is suspected, your doctor may order tests to confirm amyloidosis of that organ. For example:

• Abdominal ultrasound may reveal enlarged liver or spleen.
• A biopsy of a tissue or organ will be positive for amyloid. A skin biopsy that includes subcutaneous fat, a rectal mucosa biopsy, or a bone marrow biopsy can help confirm the diagnosis.
• A heart evaluation may reveal arrhythmias, abnormal heart sounds, or signs of heart failure.
  • An ECG shows abnormalities.
  • An echocardiogram shows poor motion of the heart wall, due to a stiff heart muscle (cardiomyopathy).
• Evaluation for carpal tunnel syndrome may reveal involvement of the nerve:
  • Hand grips are weak because of weakness of the thumb.
  • Nerve conduction velocity shows a conduction block.
• Kidney function evaluation may reveal kidney failure or nephrotic syndrome (too much protein in the urine).
  • BUN is increased.
  • Serum creatinine is increased.
  • Urinalysis shows protein, casts, or fat bodies.

This disease may also alter 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