Forms of amyloidosis and where amyloid comes from
Amyloid is not one protein, but a whole family: depending on the precursor protein, different types of the disease are distinguished. AA amyloidosis develops against the background of long-term inflammation, when the liver produces acute phase protein for years. AL amyloidosis is associated with an abnormal clone of plasma cells that produce immunoglobulin light chains and is a blood disease. There are also hereditary forms, including periodic disease, common among the peoples of the Mediterranean and the Middle East. The type of amyloid determines treatment, so efforts are made to determine it accurately.
- AA amyloidosis is the outcome of chronic inflammation
- AL amyloidosis - associated with plasma cell disease
- Hereditary forms, including periodic illness
- Dialysis amyloidosis with long-term hemodialysis
- Senile systemic amyloidosis
Causes and risk factors
The AA form is provoked by diseases in which inflammation lasts for years: rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel diseases, chronic suppurative processes, tuberculosis, bronchiectasis, osteomyelitis. Periodic illness without treatment is also often complicated by renal amyloidosis. The AL form is associated with monoclonal gammopathy and myeloma. The longer and more active the underlying disease is, the higher the risk.
- Rheumatoid arthritis and other rheumatic diseases
- Periodic disease (familial Mediterranean fever)
- Chronic purulent processes, osteomyelitis, bronchiectasis
- Tuberculosis
- Inflammatory bowel diseases
- Myeloma and monoclonal gammopathy
Symptoms
The first and for a long time the only sign is protein in the urine, discovered by chance. Then nephrotic syndrome develops: severe edema, foamy urine, decreased blood protein and increased cholesterol. Since amyloid is deposited in other organs, signs of damage to the heart, intestines and nerves may occur. Especially characteristic of the AL form are enlarged tongue, bruises around the eyes and severe weakness.
- Swelling of the legs, lower back, face, fluid accumulation in the abdomen
- Foamy urine and massive proteinuria
- Weakness, decreased blood pressure, dizziness when standing up
- Shortness of breath due to heart damage
- Persistent diarrhea or constipation
- Numbness and burning in the feet and hands
Diagnostics
The examination begins with a urine test and assessment of daily protein loss, then creatinine, total protein and blood albumin, and lipids are determined. The next task is to prove the presence of amyloid and establish its type. To do this, a biopsy of the kidney or other available tissue is performed with Congo red staining. Additionally, they look for the cause: they examine the joints, lungs, intestines, and conduct tests for monoclonal protein. All this is done in stages, the nephrologist selects the plan.
- General urine analysis and daily proteinuria
- Creatinine, urea, GFR calculation
- Total protein, albumin, lipid profile
- Kidney biopsy with Congo red staining
- Amyloid typing
- Search for underlying disease: tests for inflammation, blood tests
Treatment and observation
The main principle is to target the source of amyloid. In the AA form, stable remission of the inflammatory disease is achieved; for periodic illness, the basic treatment is colchicine, prescribed for life. In the AL form, treatment is carried out by a hematologist, using regimens that suppress the plasma cell clone. At the same time, they protect the kidneys: control blood pressure, reduce protein loss, correct swelling with diuretics, and select a diet. All medications are prescribed by a doctor; Self-medication and dietary supplements for amyloidosis are not only useless, but also a dangerous waste of time.
- Active treatment of the underlying disease
- Colchicine for periodic illness as prescribed by a doctor
- Hematological therapy for AL amyloidosis
- Control of blood pressure and proteinuria
- Diuretics and salt restriction for edema
- Regular monitoring of kidney function
- In the terminal stage - renal replacement therapy