What Is Primary Amyloidosis?

Primary amyloidosis is a rare but serious condition in which antibody production becomes abnormal, resulting in the protein components of antibodies building up in various parts of the body. These proteins, referred to as amyloid, can accumulate in the skin, body tissues, organs, blood vessels and nerves. A variety of symptoms then develop depending on the area affected, but the overall effect is to interfere with normal body function. Most often, the heart and kidneys are affected, which can lead to severe complications. There is no truly effective treatment for primary amyloidosis, and the best survival rates tend to approach 18 months.

Two different types of amyloidosis exist. Primary amyloidosis, or primary systemic amyloidosis, has no known cause and most frequently affects older people, around the age of 65. Secondary amyloidosis is amyloidosis that is caused by another pre-existing disease, commonly a long-term infection or inflammatory condition. With treatment, those with secondary amyloidosis can live 15 years or more after their condition appears. The cells responsible for the abnormal antibody production seen in amyloidosis are part of the immune system and are known as plasma cells.

Symptoms of primary amyloidosis can be quite variable, as different parts of the body may be affected by the build-up of proteins. As symptoms are often shared by other conditions, this makes diagnosis difficult and doctors suspect that many cases of primary amyloidosis may remain undiagnosed. Some possible symptoms include fatigue, weight loss, an increase in tongue size and skin lumps. Parts of the body may become swollen and the liver might be enlarged.

Diagnosing primary amyloidosis could involve taking a tissue sample from a skin lump, if any are present. This is the simplest option for doctors. If the skin is not affected, a small sample might be taken from the rectum or from belly fat. In cases where none of these sites shows evidence of amyloid, samples might have to be taken from other, less accessible, organs. An ultrasound scan might show changes in the heart, such as thickening of the chamber walls.

As there is no cure, the treatment of primary amyloidosis consists of prolonging life and managing complications where possible. For some patients, chemotherapy helps improve their condition, while others may find it beneficial to have stem cells transplanted. Without any treatment, most patients would only survive for around seven months. Most often, complications affecting the heart and kidneys lead to organ failure and death. Those patients who receive treatment may survive for up to 18 months.