The rare group of conditions collectively called amyloidosis occur when abnormal proteins called amyloids accumulate in the tissues and organs. There are several types of amyloid proteins, and they can build up in various organs, often targeting the spleen, heart, liver and kidneys, digestive tract, and nervous system. The symptoms that result, and the treatments to control them, depend on the type of protein and the site of its accumulation.
Amyloidosis
There are three basic causes of amyloidosis. A patient can inherit the hereditary form that usually affects the nervous system, heart, liver and kidneys. Primary amyloidosis occurs when a malfunction in the bone marrow causes the excessive production of antibodies that do not degrade normally. Doctors are not sure what triggers the bone marrow malfunction. Deposits form in the skin, nerves, blood vessels and heart, liver, kidney and digestive tract. Secondary amyloidosis arises as a consequence of chronic inflammation or an infectious disease. Symptoms primarily appear in the lymph nodes, kidneys, liver and spleen. Patients with Alzheimer's disease or those on dialysis can also develop forms of amyloidosis.
Treatment Goals
No intervention can cure amyloidosis. The various treatments aim to minimize the symptoms that develop when the amyloid proteins accumulate in particular tissues, and to decrease production of the abnormal proteins. For patients with secondary amyloidosis, curing or treating the underlying chronic condition often stops the production of amyloid.
Medicines
A doctor might prescribe medications to control particular symptoms, such as diuretics to improve kidney function and pain medications. Some patients benefit from chemotherapy, which kills the cells that produce the abnormal protein. The Merck Manual cites the use of the chemotherapy drug melphalan in combination with the steroid prednisone. Other patients might benefit from corticocorticoids to suppress the immune system and slow the production of antibodies.
Stem Cells
Some patients with primary amyloidosis can benefit from stem cell therapy. This treatment involves infusion of blood stem cells into bone marrow after intentional destruction of the existing malfunctioning bone marrow cells. The treatment itself can make the patient very sick; according to the Mayo Clinic, it is not entirely clear that the benefits outweigh the risks.
Organ Transplant
If amyloid deposits severely damage the heart, kidneys or liver, a doctor might recommend transplantation. Organ transplant is not a cure, because the proteins will deposit in the transplanted organ. But it does buy the patient some time. According to the Merck Manual, patients with hereditary amyloidosis make the vast majority of amyloid in their livers, and transplant of a healthy liver can halt further production and slow the disease.
