Primary Amyloidosis - Causes, Symptoms, Diagnosis, and Treatment

Introduction

Primary amyloidosis, or AL amyloidosis (amyloid light chain), is a rare disorder caused by a mutation of the plasma cells in the bone marrow. As a result of the mutation, the plasma cells create an abnormal protein. This protein gets into the tissues and organs. In primary amyloidosis, the protein that gets mutated is light chain protein, thus called AL Amyloidosis. The heart and kidneys are the most affected organs. But it also affects the liver, nerves, skin, spleen, stomach, and intestines. In one million, around 5 to 12 people are affected by amyloidosis. Males are more likely to get affected than females.

What Causes Amyloidosis?

Primary amyloidosis is a plasma cell disorder. A mutation in the plasma cells of bone marrow causes amyloidosis. These mutated plasma cells produce an abnormal light chain protein and deposit it in the bloodstream. Then, these abnormal light chain proteins clump together and form amyloid fibrils. The amyloid fibrils are difficult to remove from the body, so it gets deposited in tissues and organs. Gradually, the functions of the organs are affected, and they start to show symptoms of amyloidosis.

What Are the Symptoms of Amyloidosis?

The symptoms of amyloidosis develop slowly over time. It affects many body parts, including the head, neck, arms and legs, heart, kidney, lungs, stomach, and intestines.

Symptoms that affect the heart and lungs are:

• Chest Pain: Sharp or dull pain anywhere around the chest. If the pain persists after five minutes or even after taking rest, it should be considered a sign of a heart attack, and seek immediate medical help.

• Palpitations: It is the feeling of an increased heartbeat.

• Dyspnea: Shortness of breath.

• Fatigue.

Symptoms that affect the kidneys are:

• Swelling in the legs (edema).

• Tiredness.

• Loss of appetite.

• Increased or decreased frequency of urination.

Symptoms that affect the head and neck are:

• Purpura (purple color rash) around the eyes.

• Lightheadedness.

• Enlarged tongue.

Symptoms that affect arms and legs are:

• Numbness of arms and fingers.

• Burning sensation in the arms and fingers.

• Swelling in the feet.

• Weak legs.

Symptoms that affect the stomach and intestines are:

• Bloating.

• Loss of appetite.

• Constipation.

• Diarrhea.

How to Diagnose Amyloidosis?

• Laboratory Tests: Blood and urine are tested for abnormal proteins. Thyroid and kidney function tests are also done for some patients.

• Biopsy: A small sample of tissue is removed and tested. Different biopsies like bone marrow biopsy, kidney biopsy, heart biopsy, and fat pad biopsy are done.

• Echocardiogram: Sound waves create moving images showing the heart's functioning.

• Magnetic Resonance Imaging (MRI): Using strong magnetic fields and radio waves, detailed pictures of tissues and organs are created.

• Nuclear Imaging: Small amounts of radioactive tracers are injected into the vein to detect early heart damage caused by amyloidosis. It can also help to differentiate between the types of amyloidosis, which is necessary for treatment.

What Is the Treatment of Primary Amyloidosis?

Primary amyloidosis has no absolute cure. But with treatment, symptoms can be relieved, and further disease progression can be slowed. It can be treated in two ways, medications, and surgery.

Medications:

• Chemotherapy - Some cancer medications are given to prevent plasma cells from making the light chain protein.

• Steroids - Steroids are given in combination with chemotherapy drugs to increase effectiveness.

• Heart Medications - Anticoagulants (blood thinners) are given to reduce the risk of blood clotting. Also, medicines for reducing heart rate are given. Medicines such as Patisiran, Inotersen, Tafamidis, and Diflunisal are given.

Surgical Procedures:

• Stem Cell Transplantation - This procedure involves collecting blood stem cells through a vein and storing them for a short period while the chemotherapy dose is elevated in the blood. Stem cells are then injected back into the body via a vein. This mode of treatment is appropriate in the early stages of amyloidosis.

• Organ Transplantation -An organ transplant is suggested if the heart and kidneys are severely damaged.

Other procedures:

• Dialysis - If the kidneys are severely damaged, dialysis is recommended to filter out the wastes.

What Are the Complications of Primary Amyloidosis?

• Heart- Amyloid deposits affect the heart's blood-pumping ability, thus causing shortness of breath. When the amyloid affects the heart, it becomes life-threatening.

• Nervous System - Damage to the nerves causes pain, tingling, and numbness in the fingers and feet. Damage to the nerves of bowel functions causes diarrhea and constipation.

• Kidney - Amyloidosis affects the kidneys' filtering capacity, eventually causing kidney failure.

What Are the Risk Factors?

• Age - People above 60 years are more likely to get amyloidosis.

• Sex - Males are more likely to get amyloidosis than females.

• Race - African peoples appear to be at a higher risk of genetic mutation-associated amyloidosis.

• Family History - Some types of amyloidosis are hereditary.

• Kidney Dialysis - Patients on dialysis are at a higher risk of amyloidosis.

• Other Diseases - Chronic inflammatory diseases increase the risk of amyloidosis.

What Are the Other Types of Amyloidosis?

• AA Amyloidosis - It is known as secondary amyloidosis. Inflammatory conditions like rheumatoid arthritis mostly trigger it affecting the kidneys, spleen, and liver.

• Hereditary Amyloidosis - In this inherited type of amyloidosis heart, kidneys, and nerves are the most affected organs.

• Localized Amyloidosis - It affects only a localized part of the body, such as the lungs, skin, bladder, or throat. It has a better prognosis than the other types of amyloidosis.

• Wild-type Amyloidosis - Also called senile systemic amyloidosis. It occurs due to unknown reasons.

Conclusion

Primary amyloidosis or AL amyloidosis is a rare disease caused by abnormal light chain protein deposition in the tissues and organs. It can become a life-threatening condition if left undiagnosed or untreated. But the disease severity can be decreased with medication such as chemotherapy and other drugs. In some advanced stages, surgical procedures like stem cells and organ transplants can help prevent disease progression. Even if amyloidosis is a rare and dangerous disease, with timely diagnosis and proper treatment, the symptoms can be controlled and make the patient's life better.