Amyloidosis is a rare disorder characterized by the deposition of abnormal protein called amyloid in the body.
Amyloid is an abnormal protein built up of fibril proteins (95%), the P component and several glycoproteins. In the microscope amyloid is seen as an extracellular hyaline substance. The three common forms of amyloid are distinguished:
- AL (amyloid light chain) – consists of the light immunoglobulin chains;
- AA (amyloid-associated) produced in the liver;
- Aβ – typical for Alzheimer disease;
Amyloidosis results in the multiple organ failure.
Amyloidosis may be systemic when multiple organs are affected or localized when amyloid is found in solely organ. Primary amyloidosis treatment is usually associated with the impaired immunity and secondary amyloidosis treatment is related to other chronic inflammatory conditions. There is also a separate group of hereditary (familial) amyloidosis conditions.
Common symptoms of amyloidosis include:
- Fatigue and weakness;
- Edema (swelling of the feet or legs, less commonly – the face);
- Shortness of breath;
- Arrythmia (abnormal heart rhythms);
- Appetite and weight loss;
- Paresthesias (abnormal sensation in the fingers and toes);
- Bruising and bleeding easily;
- Nails damage and hair loss (alopecia);
- Difficulties swallowing;
- Macroglossia (large tongue);
Commonly steroids in combination with other medications are effective in the treatment of amyloidosis.
The most widely used regimen includes melphalan and dexamethasone (per os) or high-dose melphalan (IV) with autologous stem cell support.
Targeted therapy is a specific kind of treatment which influences on the genes or proteins involved in the pathogenesis of the disease.
In amyloidosis treatment immunomodulatory medicines (lenalidomide, pomalidomide, and thalidomide), monoclonal antibodies (daratumumab, gantenerumab, and elotuzumab) and proteasome inhibitors (bortezomib, ixazomib, and carfilzomib) are used.
Monoclonal antibodies affect the proteins by binding them, whereas proteasome inhibitors influences the digestion of the proteins by the proteasomes.
A brand new drug Tafamidis meglumine (Vyndaqel®, Pfizer) was developed to slow down the progression of ATTR and has been reported to show clinical efficacy in familial amyloid polyneuropathy administered at a dosage of 20 mg once per day.
Chemotherapy help destroy the abnormal cells present in blood in amyloidosis treatment. Chematherapeutical agents may be administered both intravenously or orally.
Cyclophosphamide and melphalan are commonly used. However, chemotherapy is usually combined with dexomethasone or prednisone.
Chemotherapy is associated with various side effects such as nausea, vomiting, anemia, and fatigue.
Liver transplantation is effective in ATTR Amyloidosis treatment since the liver produces abnormal transthyretin. Heart or kidney transplantation is a life-saving surgery in case of organ insufficiency.
A treatment option for Amyloidosis treatment is a bone marrow or stem cell transplantation. A bone marrow/stem cell transplantation is done after the course of chemotherapy, which ruins the person’s own bone marrow. Nowadays peripheral blood stem cell transplantation is performed.
- Pacemaker transplantation may be required if the conduction system of the heart is damaged.
- Non-steroidal anti-inflammatory drugs are prescribed to treat the underlying condition (for example, rheumatoid arthritis) and alleviate the pain.
- Doxycycline was reported to be helpful in reduction of arthralgia.
- Loop diuretics (furosemide) are administered to reduce the swellings and fluid accumulation in various body parts in kidney and heart insufficiency.
- Antiarrhytmic drugs, calcium channel blockers, digoxin, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers and beta blockers are prescribed to support the heart functioning.
- Angiotensin receptor blockers and beta blockers are necessary to control the blood pressure.
- Sedating antihistamines (Chlorpheniramine, Diphenhydramine) and topical menthol cream are used to reduce the pruritus.
- Topical corticosteroids (0,1% Betamethasone 17-valerate ointment), topical anti-inflammatory agents such as Dimethyl sulfoxide (10-100%), topical calcineurin inhibitors (0.1% Tacrolimus oinment) are used to lessen the skin lesions.