Did you know that in the United States, over 550,000 people are on dialysis because of kidney disease? If you’re one of those people, it’s important to know the facts about your risk of developing dialysis-related amyloidosis.

Dialysis-related amyloidosis can develop in people who have been on long-term dialysis. Normally, your kidneys do the job of filtering waste products and extra fluid out of your blood. In people with kidney failure, the kidneys can no longer do their job. Dialysis is the process of removing the blood from your body and moving it through a machine. The machine contains a dialyzer, a filter that takes the place of your kidneys. Dialysis is lifesaving, but dialysis-related amyloidosis can be a side effect that can occur over time.

In this article, we’ll discuss why dialysis-related amyloidosis happens and the common symptoms of this condition.

How Does Dialysis Cause Amyloidosis?

There are two types of dialysis: hemodialysis and peritoneal dialysis. In hemodialysis, a needle in your arm removes blood and returns it after filtering it outside the body. In peritoneal dialysis, the blood exchange happens through tiny blood vessels in your abdomen. Both can cause dialysis-related amyloidosis. The filter used in dialysis can’t do as good a job as functioning kidneys.

In people who have been on dialysis for several years and have no remaining kidney function, a specific protein will start to build up in the blood. This protein is called beta-2 microglobulin. Beta-2 microglobulin can’t be totally removed from your blood by the dialysis filter. The extra beta-2 microglobulin forms clumps called amyloid fibrils. These amyloid fibrils build up in different parts of your body and cause symptoms.

How Common Is Dialysis-Related Amyloidosis?

As dialysis technology has gotten better over time, the number of people developing dialysis-related amyloidosis has gone down. Specifically, the filters used in dialysis have moved from low flux (older type of filters) to high flux (newer, more efficient filters). High-flux dialysis membranes do a better job of removing beta-2 microglobulin. However, high-flux dialysis membranes still can’t remove all the beta-2 microglobulin that builds up.

It’s difficult to get exact numbers for how common this disease is. Many studies were done before the newer dialysis technology was widely used. Today, almost everyone on dialysis in the U.S. uses high-flux biocompatible dialysis membranes. However, one recent study from 2019 found that among 199 people on dialysis, nearly 21 percent had dialysis-related amyloidosis.

Certain people are at more risk of developing dialysis-related amyloidosis. Risk factors for developing dialysis-related amyloidosis include:

• Being older in age
• Being on dialysis for over five years (because it takes time for the protein to build up)
• Using low-flux dialysis membranes in the past
• Not having any kidney function

Next, we’ll cover different symptoms that you might experience with dialysis-related amyloidosis.

1. Bone, Joint, and Muscle Problems

Dialysis-related amyloidosis is different from other types of systemic amyloidosis like AL amyloidosis or AA amyloidosis. In dialysis-related amyloidosis, the amyloid fibrils build up mostly in bones, joints, and muscles. The symptoms of this type of amyloidosis are related to joint function and bones. It’s rare to get dialysis-related amyloid deposits in other parts of the body like the heart or liver. This usually only happens in people who have used dialysis for over 10 to 15 years. Systemic involvement in dialysis-related amyloidosis doesn’t usually cause any noticeable symptoms, unlike other types of amyloidosis.

2. Shoulder Pain

Shoulder pain is one of the most common symptoms of dialysis-related amyloidosis. This is caused by amyloid fibrils building up in the rotator cuff. The rotator cuff is a group of muscles and tendons around your shoulder. These muscles help you turn and rotate your shoulder. The pain in your shoulder may prevent you from getting the full range of motion in this joint. The pain is often worse when you’re getting dialysis treatment or lying down and at night. You may also have difficulty getting dressed.

3. Hand and Finger Pain

Another common place you might have symptoms of dialysis-related amyloidosis is your hand. Carpal tunnel syndrome is one frequent complication. When amyloid deposits press on the nerve running down the inside of your wrist, it can cause pain and weakness in your hand. You may have trouble gripping objects. Feelings of burning, numbness, and pins and needles are also common. Both hands are often affected, and the pain is usually worse during dialysis and at night.

Another complication of dialysis-related amyloidosis is a condition called trigger finger. This condition is also known as flexor tenosynovitis. People with dialysis-related amyloidosis often have trigger finger in multiple fingers. Your finger may feel locked or caught into position when bending. Flexor tenosynovitis is caused by amyloid deposits building up in the tendons of your fingers.

4. Bone Fractures

When amyloid deposits build up inside your bones, they can cause bone cysts. These are fluid-filled holes in bone that make it more prone to breakage. Bone cysts occur most often in your hands. They can also be found in your thigh bone (called the femur), upper arm bone (the humerus), and kneecap. You may feel stiffness or pain in the area with a bone cyst. The bone cyst can weaken the bone enough to cause a fracture, a break, or a crack in the bone. This happens mainly in the top of your femur and can cause leg pain while walking.

5. Neck and Back Pain

Axial spondyloarthritis, a type of inflammatory arthritis that affects your spine, is a possible complication of dialysis-related amyloidosis. Amyloid deposits can build up in the bones that make up your neck (cervical vertebrae) or lower back (lumbar vertebrae). The amyloid fibrils cause inflammation, leading to neck or back pain.

6. Gastrointestinal Symptoms

Symptoms outside the bones and joints are uncommon with dialysis-related amyloidosis. However, if there is amyloid buildup in other organs, it’s usually in the digestive (gastrointestinal) tract. The digestive tract includes your mouth, esophagus, stomach, and small and large intestines. The most common symptoms of gastrointestinal involvement in dialysis-related amyloidosis include:

• Enlarged tongue, also called macroglossia
• Difficulty or pain when swallowing
• Pain in the gut due to reduced blood flow (called infarcted bowel)
• Bleeding in the gastrointestinal tract

How Is Dialysis-Related Amyloidosis Treated?

There’s no cure for dialysis-related amyloidosis right now. However, your healthcare team will focus on treatments that reduce your symptoms. These might include:

• Physical therapy and braces for your joint pains
• Anti-inflammatory medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids like prednisone for joint pain
• Topical analgesics such as topical capsaicin
• Surgery for specific symptoms like carpal tunnel syndrome

Your healthcare team may also change your dialysis treatment to try to increase beta-2 microglobulin removal from your blood. This can slow the development of symptoms. Treatment options might include using newer types of dialysis filters and increasing the duration or frequency of dialysis. For some people, a kidney transplant is also an option.

Talk With Others Who Understand

MyAmyloidosisTeam is the social network for people with amyloidosis and their loved ones. On MyAmyloidosisTeam, members come together to ask questions, give advice, and share their stories with others who understand life with amyloidosis.

Have you been diagnosed with dialysis-related amyloidosis? Do you want to know more about symptoms and treatments for this condition? Share your experiences in the comments below, or start a conversation by posting on your Activities page.