Amyloidosis (Amyloid Dystrophy)

What is Amyloidosis (Amyloid Dystrophy)?

Amyloidosis (amyloid dystrophy) is a violation of protein metabolism, accompanied by the formation and deposition in the tissues of a specific protein-polysaccharide complex – amyloid. Amyloid persists for a long time in the body and even after death does not rot for a long time.

Causes of Amyloidosis (Amyloid Dystrophy)

The development of amyloidosis is associated with a violation of the protein-synthetic function of the reticulo-endothelial system, the accumulation in the blood plasma of abnormal proteins that serve as autoantigens and cause the formation of autoantibodies. As a result of the interaction of the antigen with the antibody, coarse-dispersed proteins are involved in the formation of amyloid. Deposing in the tissues (for example, in the walls of blood vessels, glandular, etc.), amyloid replaces functionally specialized elements of the organ, which leads to the death of this organ.

Pathogenesis during Amyloidosis (Amyloid Dystrophy)

AL-amyloidosis (immunoglobulin light chains derived) – primary amyloidosis caused by the accumulation in the blood plasma of abnormal light chains of immunoglobulins synthesized by malignant B lymphocytes in myeloma (Rustitsky-Kalera disease)

AA-amyloidosis (acquired) is a secondary amyloidosis caused by hypersection of the acute phase alpha globulin by the liver in response to chronic (usually purulent) inflammation. An example of such inflammations is leprosy, bronchiectasis, tuberculosis, etc. A subspecies of this amyloidosis is ASC-amyloidosis (systemic cardiovascular), which develops in people over 90 years old. The causes of pathogenesis are unknown.

AF-amyloidosis (Mediterranean intermittent fever) is a hereditary form of amyloidosis, with an autosomal recessive transmission mechanism. This type of amyloidosis affects people belonging to certain ethnic groups living along the coast of the Mediterranean Sea (Sephardic Jews, Greeks, Arabs, Armenians). There are varieties of amyloidosis characteristic of a particular geographic area: “Portuguese amyloidosis” (with predominant damage to the nerves of the lower extremities), “American amyloidosis” (with predominant damage to the nerves of the upper extremities), familial nephropathic amyloidosis, or “English amyloidosis” that occurs with symptoms of urticaria deafness and fever.

AH-amyloidosis (hemodialisis-related) is observed only in patients undergoing hemodialysis treatment. The pathogenesis is associated with the fact that, normally, kidney-utilized beta-2-microglobulin MHC class I, is not filtered in hemodialysis and accumulates in the body.

AE-amyloidosis is a form of local amyloidosis that develops in some tumors, for example, in the medullary carcinoma of the C-cells of the thyroid gland. In this case, the precursor of amyloid are pathological fragments of calcitonin.

Finnish-type amyloidosis is a rare type of amyloidosis caused by a mutation of the GSN gene encoding the protein jelsolin.

Symptoms of Amyloidosis (Amyloid Dystrophy)

The intensity of clinical manifestations depends on the location and extent of amyloid deposits. This causes the duration of the disease and the presence of complications. Kidney damage is most typical, sometimes there are lesions of the esophagus, spleen, intestines, and also of the stomach. With kidney amyloidosis, there is a long latent period of the disease, in which there are no significant symptoms, only slight weakness and a decrease in activity are observed. After two weeks of the latent period, edema of the kidneys, their dysfunction (the appearance of proteins in the urine – the development of proteinuria, as well as blood cells), heart failure appear. When amyloidosis of the stomach, there is a heaviness in the epigastric region, weakening of the motility of the stomach after eating food. With intestinal amyloidosis, there is a heavy and dull pain in the abdomen, diarrhea.

Diagnosis of Amyloidosis (Amyloid Dystrophy)

  • In the blood, anemia, leukocytosis, increased ESR, in almost 80% of cases, at the onset of the disease, a decrease in the amount of proteins, hyperglobulinemia, decrease in sodium, platelets, calcium occur. With liver damage – increased cholesterol, in some cases – increased bilirubin, increased alkaline phosphatase activity
  • Evaluation of thyroid function – possible reduction of thyroid function
  • Assessment of kidney function – in almost 50% of cases, amyloidosis begins with renal failure. In the study of urine, in addition to protein, cylinders, red blood cells, white blood cells are found in the sediment
  • In primary amyloidosis, an increase in amyloid content is found in the blood plasma and / or urine
  • When secondary amyloidosis should pay attention to laboratory signs of chronic inflammatory diseases
  • In the feces – a large amount of fat, starch, muscle fibers
  • Echocardiography (for suspected heart disease)
  • X-ray examination
  • Functional clinical tests with Congo red and methylene blue (the rapid disappearance of dyes when administered intravenously from blood serum due to their fixation by amyloid and a significant decrease in their excretion by the kidneys). In primary amyloidosis, these samples are not always informative
  • Organ biopsy is the most informative method

Treatment of Amyloidosis (Amyloid Dystrophy)

General principles for the treatment of amyloidosis

  • Home mode, with the exception of severe conditions (severe heart failure, chronic renal failure)
  • Patients with amyloidosis show a prolonged (1.5-2 years) reception of a raw liver (100-120 g / day)
  • Restriction of protein and salt intake in patients with chronic renal failure
  • Limiting salt to patients with heart failure
  • In case of secondary amyloidosis, treatment of the underlying disease (tuberculosis, osteomyelitis, empyema, etc.), after treatment of which the manifestations of amyloidosis often disappear
  • Transfer of a patient with dialysis amyloidosis to peritoneal dialysis
  • When intestinal amyloidosis occurs with persistent diarrhea – astringents (bismuth subnitrate, adsorbents)
  • In primary amyloidosis in the initial stages of the process – chloroquine 0.25 g 1 r / day for a long time, a combination of melphalan and prednisolone, melphalan, prednisolone and colchicine or just colchicine
  • In secondary amyloidosis, specific treatment of the underlying disease.
  • With familial amyloidosis – colchicine (0.6 mg 2-3 r / day)
  • Symptomatic therapy: vitamins, diuretics, drugs that reduce pressure, plasma transfusions, etc.

Surgical treatment of amyloidosis

  • Removal of the spleen may improve the condition due to a decrease in the amount of amyloid produced in the body.