Amyloidosis is a systemic pathology characterized by impaired metabolic processes in the body and depression of the immune system.
Such disorders lead to the formation of a specific protein-saccharide complex. Gradually, it begins to be deposited in the tissues of all organs, displacing healthy cells. Because of this pathological process, the activity of the whole organism is disrupted, polyorgan insufficiency develops, as a result of which a lethal outcome occurs.
Amyloidosis is a rare systemic disease. In most patients, it has a secondary nature. Inhabitants of the Mediterranean, as well as people of Jewish and Armenian nationality, the disease is due to genetic predisposition.
The following types of amyloidosis are distinguished:
- Primary amyloidosis, or AL-amyloidosis (immunoglobulin light chains derived). Its development is associated with the appearance in the blood plasma and the deposition of abnormal light chains of immunoglobulins in the tissues of the body. They, in turn, are synthesized by malignant plasma cells. The same process is observed in multiple myeloma, although there are significant differences in the development mechanism between it and amyloidosis.
- Secondary amyloidosis, or AA-amyloidosis (acquired). It occurs in any chronic inflammatory processes in the body when the liver responds to their presence with alpha-globulin hypersecretion. This form of the disease develops on the background of rheumatoid arthritis, ankylosing spondylitis, tuberculosis, leprosy, and other pathologies. People over the age of 70 often develop ASC amyloidosis. This is a subtype of the form of amyloidosis, the exact pathogenesis of which is unknown.
- Mediterranean intermittent fever. This disease is transmitted through the genetic line in an autosomal recessive manner. Separate ethnic groups of people living on the Mediterranean coast suffer from this type of pathology. There are also subspecies of this pathology. For example, with "Portuguese" amyloidosis, nerve endings in the legs are affected. With "American amyloidosis," the nerves of the hands suffer. Another subspecies is familial nephropathic or “English” amyloidosis, which is characterized by the manifestation of symptoms of urticaria, fever, and deafness.
- AH-amyloidosis. The disease develops only in patients who are on hemodialysis. The onset of the pathological process is associated with the inability of the hemodialysis machine to filter microglobulin beta-2 of the MHC 1 class, which is utilized by healthy people in the kidneys.
- AE-amyloidosis. The disease develops in the cells of certain tumor neoplasms. For example, the pathological process can affect the C-cells of the thyroid gland in the form of medullary cancer.
- ASC1-amyloidosis, or senile systemic amyloidosis. Before the formation of a mutant protein, prealbumin metabolism in the blood occurs in the elderly.
- Aβ-amyloidosis. This type of disease is especially common in Alzheimer's patients. But in medical practice there are cases of familial incidence of this type of amyloidosis.
- AIAPP amyloidosis. The disease occurs in patients with lesions of the islets of Langerhans. In diabetes mellitus type 2 and insulinoma, this part of the pancreas is affected, and AIAPP-amyloidosis develops in the background.
- Amyloidosis of the Finnish type. This form of the disease is quite rare. The disease develops against the background of a mutation of the GSN gene, which is responsible for coding the protein jelsolin.
Causes of amyloidosis
Various proteins can cause amyloid deposits. However, there is a group of proteins, under the influence of which there is a serious violation of the activity of internal organs. Amyloids can accumulate in a separate area of the body, and throughout the body.
The causes of amyloidosis depend on its type.
This type of disease has an idiopathic nature. In other words, it develops for unknown reasons, and it is impossible to establish them. But it is often detected in patients suffering from multiple myelomas.
In this case, speaking of systemic damage, implies a violation of the activity of the whole organism. Most often, the disease affects the liver, heart, gastrointestinal tract, certain groups of nerves and kidneys.
AL amyloidosis occurs when light chains of amyloid accumulate in the body.
The reasons for the development of this type of amyloidosis include:
- systemic lupus erythematosus;
- rheumatoid arthritis;
- inflammatory bowel disease;
- some types of malignant oncology.
Most often, this type of disease affects the tissues of the spleen, kidneys, liver, adrenal glands and lymph nodes.
Amyloidosis ATTR and 2-beta
The reasons for the development of these diseases may lie in:
- the deposition of beta-2-microglobulin in the blood;
- hemodialysis over 5 years;
- renal failure type.
The joints, bones, tendons suffer most from this type of disease.
Familial or hereditary amyloidosis (AF)
This is a rare form of amyloidosis that is inherited. Thus, the mode of transmission is genetic.
The clinical picture of amyloidosis depends on several factors:
- the duration of the pathology;
- locations of pathological deposits;
- the degree of violation of the internal organs;
- the amount of amyloid deposits;
- features of the biochemical structure of amyloid.
When the disease proceeds in the latent (hidden) phase, the patient does not experience any ailments. But as the pathological glycoprotein accumulates, the work of the affected organ is disrupted, which immediately affects the patient's well-being. It depends on where the foci of the disease, and its clinical manifestation.
Identify the disease in the early stages is possible only when conducting microscopy. But since the patient does not have subjective complaints, it is almost impossible to suspect the presence of amyloidosis.
For renal amyloidosis is characterized by the occurrence of moderate proteinuria, then - nephrotic syndrome. Such a disease may be accompanied by:
- high blood pressure;
- the development of chronic renal failure.
Amyloidosis of the heart
Cardiac amyloidosis manifests itself:
- progressive CHF.
When the pathology goes to the late stages of development, even minor physical exertion can provoke the onset of dyspnea. And progressive heart failure can lead to:
- pericarditis effusion;
- effusion pleurisy.
With the localization of amyloid deposits in the tissues of the digestive tract, first of all, an abnormal increase in the tongue should pay attention to itself. In addition, patients have the appearance of:
- constipation, which can be replaced by diarrhea;
- malabsorption syndrome;
- gastrointestinal bleeding.
In case of pathological damage of the pancreas, amyloidosis is masked as chronic pancreatitis. If amyloid deposits are localized in the liver, the patient develops cholestasis, hepatomegaly, portal hypertension.
In case of amyloid skin lesions on problem areas (neck, face, natural folds), nodular formations are formed. The disease can be masked by neurodermatitis, lichen redness and scleroderma.
With amyloidosis of the musculoskeletal system, patients suffer from:
- humeroscapular periarthritis;
- carpal tunnel syndrome;
- polyarthritis with lesion of symmetric joints.
Amyloidosis central nervous system
Amyloidosis, which affects the nervous system, is quite difficult, and is accompanied by:
- resistant cephalgia;
- orthostatic collapse;
- paralysis or paresis of the legs;
Consequences and complications
Against the background of amyloidosis, various acute pathological conditions develop, which can cause the patient's death. The most common and dangerous complications of the disease include:
- Myocardial infarction. The persistent increase in blood pressure in nephrotic syndrome and renal failure leads to an increase in the load on the heart muscle. The deposition of amyloids in the tissues of an organ leads to a serious disruption of its activity. As a result, there is an imbalance between his consumption of oxygen and its delivery. Its deficiency is particularly acute with physical exertion or emotional distress. If the death has not occurred (alas, it happens most often), then a scar is formed in the area of infarction, which only aggravates the already complicated heart activity. The result of this scarring is the development of chronic heart failure.
- Stroke - a pathological condition in which there is a violation of the blood supply to the brain tissue. Amyloidosis is characterized by the development of hemorrhagic stroke, a disease in which bleeding opens through the wall of a blood vessel that has undergone deformation. As a result, the nerve cells are soaked with blood, after which they die. Such a violation is manifested by a variety of symptoms, but the most dangerous consequence is the death of the patient.
- Thrombosis of the kidney veins. This process occurs due to the accumulation of fibrinogen and their deposition on the walls of the renal veins. Against the background of obturation of the lumen of blood vessels, renal failure develops. The disease develops when a large amount of plasma albumin is “passed through” in nephrotic kidney syndrome. At the same time, fibrinogen is not eliminated anywhere from the body, its level rises, and it begins to settle on the walls of blood vessels in the form of blood clots.
- The development of infectious diseases. The immune system of a patient with amyloidosis is practically inactive due to multiple organ failure and the active removal of proteins from the blood. Most often, patients are diagnosed with pneumonia, glomerulonephritis, pyelonephritis. Often, the skin, soft tissues, gastrointestinal tract (food toxicoinfections) also suffer. In addition, people with amyloidosis are highly susceptible to viral infections. They often develop mumps, herpes viral pathologies, etc.
Since amyloidosis is capable of affecting various internal organs, the approach to its diagnosis should be comprehensive, comprehensive. The diagnosis is based on the results of not only instrumental, but also laboratory indicators.
To identify the disease and determine its severity, it is necessary to conduct:
- ultrasound procedure;
- EchoCG (ultrasound of the heart);
Amyloidosis may be suspected if there are signs in the patient's blood when conducting laboratory tests:
An increased concentration of cylinders (cylindruria) and leukocytes (leukocyturia) is noted in the urine. But only biopsy can finally confirm or disprove the diagnosis. It is especially necessary because the above-described analysis results can occur in various diseases not related to amyloidosis.
During a biopsy for microscopic examination, tissues can be taken:
- the kidneys;
- lymph nodes;
- gums, etc.
After sampling, the biopsy specimen (obtained sample of the affected tissue) is subjected to histological examination. If during this process amyloid fibrils are detected, then the diagnosis can be considered confirmed.
There is no specific treatment aimed at eliminating amyloidosis. This is due primarily to the diversity of the clinical picture of the disease. But there are therapeutic approaches with which you can significantly slow down the development of pathology. It is on them that special emphasis is placed.
The main principles are the treatment of amyloidosis:
- The use of chemotherapeutic drugs in high dosages. This method is combined with stem cell transplantation.
- Chemotherapy as an independent method of treatment.
- Treatment of the main pathology in the secondary nature of amyloidosis.
- Liver, kidney, heart transplant surgery.
With uncomplicated amyloidosis, the prognosis is more or less favorable, but much depends on the nature of the pathology and the intensity of its progression. If complications arise, the prognosis worsens dramatically. With the development of heart failure, the patient can live no longer than several months.
In patients with chronic renal failure, the survival period is longer, and is 1 year. But this time can be extended during hemodialysis.