Definition

Amyloidosis is a rare condition characterized by the accumulation of abnormal proteins, known as amyloids, within the tissues and organs of the body. These proteins can build up in various organs, including the kidneys, liver, heart, spleen, nervous system, and digestive tract.

The deposition of amyloid proteins not only alters the structure of these tissues but also hinders their ability to function properly. Amyloidosis is a serious health issue that can become life-threatening if not appropriately treated.

There are different forms of amyloidosis, and certain types can develop alongside other diseases. If untreated, amyloidosis may lead to organ failure and potentially fatal outcomes.

Causes

Various types of proteins can lead to amyloid deposits in the body’s organs and tissues, though only a few are linked to medical conditions. Amyloid accumulation can occur either throughout the entire body or in localized areas. The specific type of amyloidosis depends on the underlying cause, which may include genetic factors, chronic inflammatory diseases, or a long history of dialysis.

The main types of amyloidosis include:

• AL amyloidosis (primary amyloidosis)

This is the most common form of amyloidosis in developed countries, typically affecting the kidneys, liver, heart, and other organs. AL stands for amyloid light chain protein, which in affected individuals is abnormal and difficult for the body to eliminate.

• AA amyloidosis (secondary amyloidosis)

This form is associated with type A amyloid protein and impacts the kidneys in 80% of cases. It can also affect the liver and gastrointestinal tract. The buildup of type A protein is often triggered by chronic inflammatory conditions, such as rheumatoid arthritis or Crohn’s disease.

• Hereditary amyloidosis

This form is inherited from family members and results from the accumulation of amyloid produced by a mutated version of transthyretin, a protein synthesized in the liver. This condition most often affects the nerves, kidneys, and heart, though some types of transthyretin amyloidosis are not inherited.

• Dialysis-related amyloidosis

This type is more common in older individuals or those who have been on dialysis for more than five years. It is caused by the buildup of beta-2 microglobulin in the blood and various tissues, typically depositing in bones, joints, and tendons.

Risk Factors

Several risk factors contribute to the likelihood of developing amyloidosis:

• Age: Amyloidosis is more common in individuals aged 60 to 70 years.
• Gender: Males are more frequently affected than females.
• Chronic infections: These can increase the risk of developing amyloidosis.
• Family history: Certain forms of amyloidosis can be inherited, increasing the risk in those with a family history of the condition.
• Long-term dialysis: Prolonged dialysis is a risk factor.
• Ethnicity: Individuals of African descent have a higher predisposition to amyloidosis.

Symptoms

The symptoms of amyloidosis may not be immediately noticeable and often become evident only after the disease has progressed for some time. The specific symptoms can vary depending on the organs and tissues affected by amyloid deposition. Since these symptoms can resemble those of other diseases, further evaluation by a doctor is necessary.

Possible symptoms include:

• Persistent fatigue and weakness
• Unexplained weight loss
• Swelling in the legs or feet
• Numbness, tingling, or pain in the hands or feet
• Easily bruised skin, skin thickening, or changes in skin color
• Purple spots (purpura) around the eyes
• Gastrointestinal issues such as diarrhea, sometimes with blood, or constipation
• Enlarged tongue
• Joint pain
• Shortness of breath

As the disease progresses, the buildup of amyloid proteins can damage major organs, including the heart, liver, spleen, kidneys, digestive system, brain, and nervous system.

Diagnosis

Although amyloidosis is a rare disease, its diagnosis follows the same principles as other conditions. It involves a medical interview between the doctor and patient, a physical examination, and additional diagnostic tests. Given that its symptoms may overlap with those of other diseases, diagnosing amyloidosis can sometimes be challenging, leading to missed diagnoses. Early detection is crucial to prevent further organ damage.

During the medical interview, the doctor will inquire about the patient's primary complaints, the onset of symptoms, medical history, past illnesses, and family medical history. A physical examination will be conducted based on the patient's symptoms.

The following diagnostic tests may be recommended:

• Blood and urine tests to detect abnormal proteins indicative of amyloidosis
• Kidney and liver function tests
• Echocardiography (heart ultrasound)
• CT scan or MRI
• Biopsy (tissue sample collection) for laboratory examination

Management

Currently, there is no definitive cure for amyloidosis. Treatment focuses on managing symptoms and reducing the production of amyloid proteins. If amyloidosis is triggered by another underlying disease, treating that condition can help alleviate amyloidosis symptoms. Below are some potential treatment approaches:

Medication

Certain types of amyloidosis may require specialized medications to stabilize proteins in the blood and prevent the formation of amyloid proteins.
If the heart is affected, blood thinners may be prescribed to reduce the risk of clotting. Additionally, some chemotherapy drugs may be used to halt the proliferation of abnormal cells producing amyloid proteins.

Stem Cell Transplant

This procedure involves collecting stem cells from the patient's blood. After the collection, the patient undergoes chemotherapy, and the stem cells are later reintroduced into the body. This treatment is suitable for patients whose condition does not severely affect the heart.

Dialysis

Dialysis is an option if amyloidosis compromises kidney function, interfering with the kidneys’ ability to filter toxins from the body.

Organ Transplantation

If amyloidosis severely damages vital organs such as the heart or kidneys, organ transplantation may be necessary.

Complications

Amyloidosis can seriously impair the following organs:

Kidneys

 Amyloid deposits can damage the kidneys' ability to filter essential substances and waste, potentially leading to kidney failure.

Heart

Amyloid buildup in the heart can reduce its ability to pump blood, causing shortness of breath. It may also disrupt the heart's electrical system, leading to life-threatening arrhythmias.

Nervous System

Nerve damage can result in pain, numbness, or tingling sensations in the hands and feet. If amyloid affects the nerves regulating bowel function, it may lead to constipation or diarrhea. Damage to nerves controlling blood pressure can cause fainting when standing up too quickly.

Prevention

There is no specific way to prevent amyloidosis. However, staying informed about the condition can help in early detection and management. Regular health checkups, either annually or every few years, can help monitor your overall health and detect potential issues early.

When to See a Doctor?

If you experience any of the aforementioned symptoms, particularly if there is a family history of amyloidosis, seek medical advice promptly. Early consultation is crucial for managing the disease and preventing complications.

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