amyloidosis what is it

3 min read 10-03-2025

Amyloidosis is a rare disease characterized by the abnormal buildup of amyloid proteins in various organs and tissues throughout the body. These amyloid deposits disrupt normal organ function, leading to a range of symptoms depending on which organs are affected. Understanding what amyloidosis is, its causes, symptoms, and treatment is crucial for early diagnosis and management.

What are Amyloid Proteins?

Normally, proteins fold into specific three-dimensional shapes to perform their functions. In amyloidosis, proteins misfold and clump together, forming insoluble fibrils called amyloid. These amyloid fibrils accumulate and deposit in tissues and organs, interfering with their normal structure and function. Different types of amyloidosis result from the accumulation of different misfolded proteins.

Types of Amyloidosis

Several types of amyloidosis exist, each classified by the type of protein that forms the amyloid deposits:

1. AL Amyloidosis (Light Chain Amyloidosis)

This is the most common type. It occurs when abnormal plasma cells in the bone marrow produce excess light chains (immunoglobulin fragments). These light chains misfold and deposit as amyloid. AL amyloidosis frequently affects the heart, kidneys, liver, and nervous system.

2. AA Amyloidosis (Secondary Amyloidosis)

This type is associated with chronic inflammatory conditions like rheumatoid arthritis, inflammatory bowel disease, and tuberculosis. In these conditions, the body produces an abnormal protein called serum amyloid A (SAA), which misfolds and deposits as amyloid.

3. Transthyretin Amyloidosis (ATTR)

ATTR amyloidosis involves misfolded transthyretin protein, a protein primarily produced in the liver. There are two main subtypes: hereditary ATTR amyloidosis (hATTR), caused by a genetic mutation, and senile systemic amyloidosis, which typically affects older individuals. ATTR commonly impacts the heart, nerves, and gastrointestinal tract.

Other Types

Other less common types of amyloidosis exist, each linked to specific proteins and potentially different clinical presentations. These include amyloid Aβ in Alzheimer's disease and amyloid β2-microglobulin in dialysis-related amyloidosis.

Symptoms of Amyloidosis

Symptoms vary greatly depending on which organs are affected and the extent of amyloid deposition. Common symptoms include:

Fatigue and weakness: A general feeling of tiredness and lack of energy.
Swelling in the legs and ankles: Fluid retention due to impaired kidney function.
Shortness of breath: Resulting from heart involvement.
Numbness or tingling in the hands and feet: Due to nerve damage.
Enlarged tongue: Amyloid deposits can cause the tongue to swell.
Heart problems: Arrhythmias, heart failure, or cardiomyopathy.
Kidney problems: Proteinuria (protein in the urine), kidney failure.
Gastrointestinal issues: Diarrhea, constipation, or abdominal pain.
Skin changes: Purple spots or skin thickening.

Diagnosis of Amyloidosis

Diagnosing amyloidosis involves a multi-step process. Doctors often rely on:

Physical examination: Assessing for signs and symptoms.
Blood tests: To check for abnormal proteins and organ function.
Urine tests: To detect proteinuria.
Biopsy: Taking a tissue sample to confirm amyloid deposits under a microscope. This is the gold standard for diagnosis.
Imaging studies: Echocardiography, MRI, or CT scans to evaluate organ involvement.

Treatment of Amyloidosis

Treatment for amyloidosis depends on the type and severity of the disease, as well as the organs affected. Options include:

Chemotherapy: For AL amyloidosis, to target the abnormal plasma cells.
Stem cell transplantation: A more aggressive approach for AL amyloidosis.
Medications to stabilize amyloid proteins: For ATTR amyloidosis, these drugs can slow the progression of the disease.
Supportive care: Managing symptoms and complications, such as heart failure or kidney failure.

Living with Amyloidosis

Amyloidosis is a chronic and often progressive condition. Living with amyloidosis requires a collaborative approach between the patient and their healthcare team. Regular monitoring of organ function, symptom management, and adherence to prescribed treatments are crucial for optimizing quality of life and extending survival. Support groups and patient advocacy organizations can provide valuable resources and emotional support.

This information is for general educational purposes only and does not constitute medical advice. Always consult with a healthcare professional for diagnosis and treatment of any medical condition.