The concept of amyloidosis
Amyloidosis is a disease inwhich is based on the heterogeneous origin of protein metabolism disorders, in which tissues in various organs is delayed substance of protein nature - amyloid. There are local and systemic amyloidosis. In the latter amyloid deposits localized only in a particular organ.
The causes and mechanism of development of amyloidosis
The nature and mechanisms of development of amyloidosis to endnot clear. It is believed that the basis of the disease is the protein products - amyloid precursor. It is influenced by the specific amyloid - releasing factor, of which the production of blood cells due to a genetic defect or under the influence of precipitating agents. Accumulation in blood precursor protein together with its catabolism disorders, and (or) resorption leads to the production of amyloid protein, of which 96-98% consists on amyloid.
Due to the lack of knowledge about the factors influencing thedevelopment of systemic amyloidosis, and the mechanism of the disease can be divided into genetic (hereditary), primary, secondary and senile. Genetic amyloidosis is caused by inherited defects in the enzyme systems involved in protein synthesis. It occurs in several forms (family, neuropathic, etc..), Including on the territory of CIS countries the most important amyloidosis in periodic disease.
Primary amyloidosis occurs sporadically, the cause has not been established. Amyloid precursor protein and amyloid fibrils are derived from immunoglobulin light chains.
Secondary amyloidosis occurs against a background markeddisorders of protein metabolism, often - as a result of chronic infections of tuberculosis, syphilis, malaria, lasting suppurative processes in the lungs, osteomyelitis. Rarely observed the development of amyloidosis in rheumatoid arthritis, chlamydia, actinomycosis, multiple myeloma. In secondary amyloidosis, amyloid protein is represented by abnormal protein amiloidvysvobozhdayuschy factor - interleukin-1.
A special place is occupied by the so-called senileamyloidosis is characterized by lesions of the heart, brain and pancreas. Most local forms of amyloidosis have established the causal factor and are referred to as idiopathic amyloidosis.
Primary amyloidosis is characterized by depositionamyloid around collagen fibers, the secondary - perivascular localization. Consequently, primary amyloidosis often affects the digestive tract, tonsils, skin, heart, great vessels and nerves, and secondary - the internal organs, and they primarily small vessels. When this substance first deposited amyloid in the wall and then spreads to the periphery of the vessel, moving further to the adjacent connective tissue.
By frequency amyloid deposits organs and systems can be arranged in the following order:
- adrenal glands
- digestive tract
- The lymph nodes
- a heart
The main symptoms of the disease
The symptoms of amyloidosis depend on the preferential localization of amyloid deposits and the degree of violation of function of the affected organ.
Amyloidosis of the heart is more often primary. It is characterized by symptoms of progressive heart failure, which in parallel with (or slightly before) there are a variety of disorders of heart rhythm and conduction.
Amyloidosis of the gastrointestinal tract usuallymanifested diarrhea syndrome, malabsorption syndrome rarely develops. With the defeat of the esophagus characterized by dysphagia. In general malabsorption lead to the development polyhypovitaminosis and weight loss up to cachexia. Often it revealed an increase in the size of the language, which leads to the idea of primary amyloidosis. Typically, an enlarged liver and spleen, not accompanied by one-third of patients with disorders of their functions.
Isolated liver amyloidosis occurs veryrare, usually occur Associated lesions, especially in secondary amyloidosis. Among the main symptoms of liver enlargement prevails, which, however, may develop in the later stages of the disease. Liver palpation dense maloboleznennaya. Jaundice is rare and is not intensive in nature. Can jaundice on the background of primary amyloidosis of the liver. In some cases, hemorrhagic syndrome may develop.