We are searching data for your request:
Upon completion, a link will appear to access the found materials.
What is amyloidosis?
In the rare disease amyloidosis, deposits occur in several organs and tissues due to abnormally folded proteins. These deposits (amyloid fibrils) can cause numerous disorders in the body, which can range from malfunctions, organ failure to death.
Amyloidosis is very rare and usually shows up in patients who are suspected of having a metabolic disorder. There is often a connection with chronic inflammation such as arthritis. The first symptoms are usually urine discoloration and proteinuria. Functional impairments of the liver and heart can also be caused by amyloidosis.
The symptoms that occur in the course of amyloidosis depend heavily on the organs and tissues in which the amyloid fibrils accumulate. Some sufferers have hardly any complaints, whereas others can be fatal. Here is an overview of the complaints:
- General symptoms: Chronic fatigue, weight loss.
- Heart affected: Arrhythmia, heart failure (heart failure), shortness of breath, weakness, fainting.
- Nerves affected: Tingling in the limbs, fingers or toes, numbness, dizziness.
- Kidneys affected: Edema on legs and feet, swelling in the abdominal region.
- Skin affected: Blue spots, skin around the eyes often turns bluish, tongue can enlarge (macroglossia).
The form, and with it symptoms and prognosis, of the disease depend on the location and severity of the disorder. The amyloidoses are divided into systemic and local. Basically, amyloids can accumulate anywhere in the body and sometimes also lead to tumor-like structures, the amyloidomas. It is important that the type of amyloid is classified when diagnosed.
An amyloid disease can be clinically normal to life-threatening and can also cause more serious symptoms and illnesses, such as
- Heart failure, restrictive cardiomyopathy and heart attack,
- Kidney failure,
- Bleeding tendencies,
- enlarged spleen,
- enlarged liver,
- Carpal tunnel syndrome.
Amyloidosis is caused by proteins that do not fold as intended. Due to this abnormal folding, the proteins cannot or cannot fulfill their task properly. As a result, clumps form which form deposits. Such deposits are referred to in medicine as amyloid deposits and amyloid fibrils. There are many different types of proteins that can be affected by abnormal folding. So there are many different forms of the disease. Some forms affect the entire body, others only occur locally and deposits only form on a certain organ.
Here is an overview of the different forms of amyloidosis that affect the entire body:
- AL amyloidosis: This form is also known as primary amyloidosis or light chain amyloidosis. The cause is abnormalities in plasma cells that lead to malformed antibody proteins. These abnormal antibodies are predominantly found in the heart, kidneys, nerves, tongue, intestines, liver, spleen and blood vessels. Light chain amyloidosis often occurs together with multiple myeloma. Around ten to 20 percent of patients with multiple myeloma also suffer from AL amyloidosis.
- AA amyloidosis: This form is also called secondary amyloidosis. The abnormal folds can be caused by persistent infectious diseases, such as tuberculosis, rheumatoid arthritis or Mediterranean fever. The deposits often accumulate in the kidneys. However, other organs can also be affected. There is an increased risk of cancer.
- AF amyloidosis: Hereditary disease is also known as familial amyloidosis. Due to hereditary mutations, misfolded proteins in the blood appear in adulthood, whereupon deposits in the kidneys, nerves or heart are preferred. A mutated liver protein called transthyretin (ATTRm) is considered the most common trigger for this form of amyloidosis.
- ATTRwt amyloidosis: This form was previously called senile systemic amyloidosis. Today the term wild-type transthyretin amyloidosis is also common. The disease is triggered by incorrect folding of the transthyretin protein. As a result, deposits occur that primarily affect the heart. This type of disease occurs much more frequently in men than in women.
In localized amyloidoses, the deposits only appear in one organ or tissue. The best-known example here is the amyloid deposits that can be found in the brains of Alzheimer's patients. With other local forms, for example, only the skin, the intestine, the respiratory tract or the bladder are affected.
An accumulation of amyloid fibrils is difficult to diagnose. The symptoms are complex and there is often a suspicion of other diseases. A relatively clear sign is an enlarged tongue, but this rarely occurs. If the doctor suspects amyloidosis, a biopsy is usually carried out for diagnosis. For this purpose, a tissue sample is taken from the abdominal fat or the tissue or the organ, which is suspected to be affected. The fibrils can then be detected in the laboratory.
The therapy depends heavily on the present form of the disease. In some cases, transplantation of the affected organ may be necessary. The following overview shows which treatment is often used in which form:
- AL amyloidosis: Chemotherapy, for example with melphalan, bortezomib or lenalidomide; peripheral stem cell transplantation can also have an effect.
- AA amyloidosis: Treatment of the underlying infection or inflammation. If the amyloidosis was triggered by the familial Mediterranean fever, the drug colchicine shows good effects.
- Family amyloidosis: Medicines such as Diflunisal and Tafamidis that stabilize the transthyretin protein and thus slow fibril formation. If the liver is affected, a liver transplant can help.
So far, there is no method that can remove already deposited amyloids. For this reason, organ damage that has occurred cannot usually be cured. Unfortunately, amyloidosis is often only secured after death as part of an autopsy. Research is currently underway on new methods such as gene therapy and drugs that dissolve deposits. A healthy lifestyle with exercise and avoidance of excess weight, low-salt diet and optimal blood pressure obviously prevents amyloidosis with symptom-related disease of organs. (vb, tf)
Author and source information
This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
Graduate Editor (FH) Volker Blasek, Dr. med. Andreas Schilling
- John L. Berk, Vaishali Sanchorawala: Amyloidose, MSD Manual, Merck and Co., Inc. As of October 2016, msdmanuals.com
- University Medical Center Hamburg-Eppendorf (UKE): Amyloidosis (access: September 6, 2019), uke.de
- Heidelberg University Hospital: Amyloidosis (accessed: September 6, 2019), Klinikum.uni-heidelberg.de
- Institute for Cardiomyopathies Heidelberg (ICH.); Heidelberg Heart Center; Heidelberg University Hospital: Cardiac amyloidosis - When the heart sticks, as of October 2017, amyloidosis center
- Carlos Fernández de Larrea, Laura Verga, Patrizia Morbini, u.a .: A practical approach to the diagnosis of systemic amyloidoses, blood journal, issue 125, 2015, bloodjournal.org
ICD codes for this disease: E85ICD codes are internationally valid encodings for medical diagnoses. You can find yourself e.g. in doctor's letters or on disability certificates.