Amyloidosis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at May 7, 2016
StartDiseasesAmyloidosis

Amyloidosis occurs when amyloid builds up inside the human body, specifically within organs. The substance is a protein generated by bone marrow, and it can absorb into any of the bodily organs or tissues. There is no known cure for the condition, but it is manageable with certain treatments.

Contents

Definition & Facts

Amyloidosis is a potentially serious issue that can lead to organ failure and death. Typically, the condition most noticeably affects the digestive tract, spleen, kidneys, liver, heart, and central nervous system. There are several different types of amyloid proteins that may form deposits within the body, and the type of protein is the primary factor in determining where the condition manifests.

There are several different types of amyloidosis, including two forms of systemic amyloidosis, dialysis-related amyloidosis, organ-specific amyloidosis, and hereditary amyloidosis. Some forms of amyloid have been known to have a link with Alzheimer's disease, but systemic amyloidosis rarely involves the brain.

Symptoms & Complaints

Noticeable symptoms are rare with amyloidosis, at least before the condition has advanced to a severe stage. The symptoms will depend on the organs that receive the amyloid deposits. Some potential signs that point to amyloidosis include:

Because of the nature of the condition, several of these symptoms presenting simultaneously does not necessarily dictate a diagnosis of amyloidosis. However, multiple symptoms might point to amyloidosis as the potential source. A doctor can perform further tests to identify the condition.

Causes

Each type of amyloidosis has a different set of potential causes, although the causes for some of them remain known. The main factors that determine the cause are the type of protein that is collecting in the organ, and what organ is receiving the deposits. Below is a list of the causes for each of the most common types of amyloidosis:

  • Primary amyloidosis - There is no known cause for primary amyloidosis, but it is common in patients experiencing blood cancer. Primary amyloidosis is the most common variety of the condition, and it mostly affects the liver, intestines, heart, and kidneys.
  • Secondary amyloidosis - The main cause of secondary amyloidosis is any of several inflammatory conditions that exacerbate the amyloidosis. Those conditions might include tuberculosis, lupus, ulcerative colitis, and even some forms of cancer. Secondary amyloidosis is less common than primary amyloidosis, and it usually affects the lymph nodes, spleen, kidneys, and adrenal glands.
  • Organ-specific amyloidosis - As the name suggests, organ-specific amyloidosis occurs when amyloid deposits affect a single organ. This type of the condition is less serious than the systemic varieties above, but it can be harder to diagnosis in its early stages.
  • Hereditary amyloidosis - In rare cases, the condition can be passed down through families. This variety of the disease is generally caused by a faulty protein made in the liver, but other hereditary factors may play a role as well.
  • Dialysis-related amyloidosis - This variety of amyloidosis tends to affect older adults who have been undergoing dialysis for over five years. Certain proteins build up in the bloodstream over time, and those deposits then accumulate in the bones, joints, and tendons.

Diagnosis & Tests

The symptoms of amyloidosis are close to those of many other, more common diseases. Because of this, amyloidosis is typically overlooked or misdiagnosed in its early stages, and sometimes even during its more severe stages. The longer a proper diagnosis takes, the greater the damage that may be done to the body. 

Once a doctor suspects amyloidosis, he or she may order further tests. Those tests might include a blood test and urine test to check for any protein markers that indicate the presence of the condition. Liver function tests and thyroid function tests are usually done as well.

Next, a biopsy may be taken from fat, bone marrow, or a potentially affected organ. Doctors can use the tissue sample to search for signs of amyloidosis, specifically by looking for amyloid deposits or signs of damage. If the condition has targeted several organs, internal imaging might be done to better understand the severity of the condition. EKGs (electrocardiograms) might be employed to investigate the effect of amyloidosis on the heart. Other imaging methods might be used to view the damage of the liver or spleen.

Treatment & Therapy

There is no known cure of amyloidosis, but it is possible to manage the symptoms with certain medicines and therapies. Certain forms of primary amyloidosis respond well to chemotherapy, since the powerful treatment stops the abnormal production of amyloid proteins. Doctors may also perform a peripheral blood stem cell transplant, which involves replacing a patient's stem cells that have been destroyed as a result of chemotherapy.

Secondary amyloidosis can be handled by treating the underlying inflammatory condition that causes the amyloidosis. Anti-inflammatory medications are the most common way to help reduce the symptoms of secondary amyloidosis. Hereditary amyloidosis is caused by a faulty protein made in the liver, so liver transplants may be the best option for treatment. Similarly, a kidney transplant might be the best option for dialysis-related amyloidosis. Medication, changes in diet and exercise, and the use of different dialysis filters may also be used to treat dialysis-related amyloidosis.

Prevention & Prophylaxis

Since the direct cause of primary amyloidosis isn't known, there are no methods to prevent the condition from developing. Maintaining a healthy lifestyle that includes a balanced diet along with plenty of rest and exercise is the best way to reduce the likelihood of amyloid deposits becoming a medical issue. Low sodium diets are thought to be beneficial for those trying to avoid amyloidosis symptoms as well.