Amyloidosis: Symptoms and Treatment | – Guide

Status: 06/14/2022 10:59

In amyloidosis, the defectively formed protein is deposited in several organs. The causes of the disease and symptoms are very different. The disease cannot be cured.

Amyloidosis is not a single disease, but an umbrella term for a whole group of diseases. What they have in common is what are known as amyloids, poorly folded protein deposits in tissue that can be microscopically stained as starch. It is known that about 30 different proteins are capable of forming amyloids. The amount of these proteins is so large that the body cannot break them down. Protein fibers alter the metabolism and function of the organs in which they are deposited. How the clinical picture manifests itself depends on which protein is responsible for the formation of amyloid.

AL amyloidosis and ATTR amyloidosis (hereditary or acquired form) are common forms, while AA amyloidosis is less common. Furthermore, a distinction is made between localized amyloidosis, in which proteins accumulate only in one place in the body, such as the skin, and systemic amyloidosis, in which amyloids are deposited in different organs. In principle, amyloidosis can affect any organ. It is often the heart, kidneys, liver, gastrointestinal tract or nervous system.

progressive disease

Amyloidosis usually progresses over time. The affected organs gradually lose their function. Depending on the type of protein that forms the amyloid, there are various ways to slow the progression of the disease. However, amyloidosis has not yet been cured.

Cause: genetic error, cancer or inflammatory disease

Hereditary amyloidosis is passed on from parents to children. An example is familial ATTR amyloidosis. The transthyretin protein is deposited as amyloid in organs such as the heart, kidneys, eyes, tendons and ligaments, as well as in the nervous system. The cause is a genetic mutation that leads to an incorrect structure of the transthyretin.

Hereditary factors play no role in most amyloidosis. AL amyloidosis is usually caused by cancer of the bone marrow and lymph nodes, such as plasma cell myeloma or non-Hodgkin’s lymphoma of the bone marrow or lymphatic system. The light chains of immunoglobulins are subunits of proteins that play an essential role in the immune system. They are deposited in the tissue in AL amidosis. Abnormal immune cells in the bone marrow or lymph glands (plasma or lymph cells) produce these abnormal light chains.

An AA amyloidosis it is due to a long-standing inflammatory disease such as rheumatoid arthritis, Crohn’s disease or ulcerative colitis. Chronic inflammation causes the liver to permanently produce excessive amounts of serum amyloid A (SAA). These proteins can turn into AA fibrils, which are deposited mainly in the spleen and later also in the kidneys. The liver and gastrointestinal tract can also be affected, more rarely the heart. AA amyloidosis itself is not inherited, but does occur with some inherited diseases.

Symptoms: fatigue, weight loss, motor weakness

As different as the causes of various amyloidoses are, they can also cause different symptoms. Symptoms are not the same or equally severe in all affected people. What is decisive is which type of amyloidosis is present and in which organs the insoluble amyloids are deposited. In the case of systemic amyloidosis, usually several organs are affected at the same time, while the protein deposits in local amyloidosis are formed only locally, for example in the skin.

The first symptoms of amyloidosis are often unusual: fatigue, exhaustion and decreased physical performance also occur in many other diseases.

Symptoms of systemic amyloidosis include:

  • Weight loss, nausea, severe fatigue, sleep disturbances
  • motor weakness and sensory disturbances in the legs
  • Disturbances of bowel and bladder function
  • high blood pressure
  • sexual dysfunctions
  • Heart failure with breathing problems, cardiac arrhythmia, tight heart, fainting, sudden cardiac death
  • Water retention in the lungs and other tissues
  • visual disturbances
  • renal dysfunction
  • thyroid dysfunction

Diagnosis: Detect amyloidosis from tissue sample

If amyloidosis is suspected, detailed diagnostics are performed to detect amyloid deposited in the tissue. This initially includes taking a tissue sample (biopsy) from abdominal fat, rectal mucosa, or the affected organ. Sometimes a bone marrow biopsy is also needed.

Determining the type of amyloidosis is also important for diagnosis. Because the type of protein that has been deposited is critical to the treatment. Additional diagnostics include, for example:

  • Urinalysis, eg. determination of the amount of protein in the urine, albumin / creatinine ratio
  • Blood test (troponin, BNP, NT-proBNP, complete blood count, electrolytes, liver values, immunoglobulins)
  • Immunohistochemical examination of the removed tissue (staining with Congo red dye, which is bound by amyloid and glows greenish under a microscope)
  • Genetic testing, for example when there is a suspicion of familial ATTR amyloidosis
  • Ultrasound (ultrasound)
  • X-ray
  • ECG and cardiac ultrasound (echocardiography)
  • Computed Tomography (CT)
  • Magnetic resonance imaging (MRI)
  • Pulmonary function test (spirometry)
  • endoscopy
  • Electromyography (EMG) to check muscle function
  • Electroneurography (ENG) to check nerve function
  • Syntigraphy of the skeleton

Treatment: relieve symptoms

Amyloidosis cannot be cured. Rather, treatment aims to relieve symptoms and slow the progression of the disease. The therapy mainly consists in the administration of drugs aimed at reducing the formation of amyloid. These include, for example

  • non-steroidal anti-inflammatory drugs
  • TTR stabilizers
  • Antisense oligonucleotide

Various medications are also used to relieve symptoms. In severe cases, a liver transplant, a heart transplant, or a combined transplant of both organs may be required.

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