Local hyalinosis. Stromal vascular dystrophies. The causes of the appearance of pathology

Rice. 11. Fibrinoid swelling.

a- fibrinoid swelling and fibrinoid necrosis of the capillaries of the renal glomeruli (systemic red
lupus); b - electron diffraction pattern: in the fibrinoid among the swollen ones that have lost their transverse striation
collagen fibers (KlV), fibrin mass (F). x 35000 (according to Gieseking).

nye (fibrinoid changes in connective tissue in rheumatic diseases
yah; capillaries of the renal glomeruli with glomerulonephritis), angioneurotic
chemical (fibrinoid arterioles in hypertension and arterial hy-
pergenia). In such cases, fibrinoid swelling is widespread
undesirable (systemic) character. As a manifestation of inflammation, especially
chronic, fibrinoid swelling occurs locally (fibrinoid
in the appendix with appendicitis, in the bottom of a chronic stomach ulcer,
trophic skin ulcers, etc.).

As a result of fibrinoid changes, necrosis develops, replacement of the focus
destruction of connective tissue (sclerosis) or hyalinosis.

Meaning fibrinoid swelling is enormous. It leads to disruption
and often the termination of organ function (for example, acute renal failure
sufficiency in malignant hypertension characterized by fibri-
noid necrosis of glomerular arterioles).

With hyalinosis (from the Greek hyalos - transparent, glassy), or
hyaline dystrophy, one-
native translucent dense masses (hyaline) 2 resembling hyaline
cartilage. The appearance in the cytoplasm of hyaline drops (hyaline-drop di-
stanza) has nothing to do with hyalinosis.

Hyalin is a fibrillar protein, in the formation of which a large role is played
belongs to plasma proteins, in particular fibrin. With immunohistochemical
a study in hyaline reveals not only fibrin, but also
nents of immune complexes (immunoglobulins, complement fractions),
as well as lipids. Hyaline masses are resistant to acids,

alkalis, enzymes, are well stained with acidic dyes (eosin,
sour fuchsin), with picrofuchsin they turn yellow or red,
CHIC are positive.

Mechanism hyalinosis is complicated. Leading in its development are destructive
ration of fibrous structures and an increase in tissue-vascular permeability
(plasmorrhage) due to angioedema (dyscirculatory), metabolic
personal and immunopatholotic processes. Associated with plasmorrhage
tissue impregnation with plasma proteins and their adsorption on altered fibers
ny structures with subsequent precipitation and protein formation -
hyaline. Hyalinosis can develop as a result of various processes: plasmati-
soaking, fibrinoid swelling (fibrinoid), inflammation,
necrosis, sclerosis.

Classification of hyalinosis. Distinguish between vascular hyalinosis and hyalinosis
specifically connective tissue. Each of them can be distributed
local (systemic) and local.

Vascular hyalinosis. Mainly mel-
arteries and arterioles. It is preceded by damage to the endothelium, argyro-
philic membranes and smooth muscle cells of the wall and impregnation of its plasma
my blood.

Microscopic picture: hyaline falls out in the subendothelial
wandering, hyaline masses push outwards and destroy the elastic
plate, lead to a thinning of the middle shell, resulting in arte-
rioles turn into thickened dense vitreous tubes with sharply
narrowed or completely closed lumen (Fig. 12).

Hyalinosis of small arteries and arterioles is systemic in nature, but most
more pronounced in the kidneys, brain, retina, half-stomach
ze, skin. It is especially characteristic of hypertension and hypertension.
medical conditions (hypertensive arteriologialinosis), diabetic mine-
croangiopathy (diabetic arteriologialinosis) and diseases with impaired
nii of immunity. As a physiological phenomenon, local hyalinosis of the arteries
observed in the spleen of adults and the elderly, reflecting the functional
nal and morphological features of the spleen as an organ of deposition
blood.

Vascular hyaline is a substance of a hematogenous nature. In his education
play a role not only hemodynamic and metabolic, but also immune
mechanisms. Guided by the peculiarities of the pathogenesis of vascular hyalinosis, you
there are 3 types of vascular hyaline: 1) simple, arising
due to insufficiency of unchanged or slightly altered plasma components
blood; occurs more often in hypertensive benign
chenia, atherosclerosis and in healthy people; 2) l and p about g and and l and n, containing
lipids and B-lipoproteins; found most often in diabetes mellitus;
3) complex hyaline, built from immune complexes, fibrin
and collapsing structures of the vascular wall (see Fig. 12), is typical for
diseases with immunopathological disorders, for example, for rheumatic
diseases.

Hyalinosis of the connective tissue itself. Is developing
usually as a result of fibrinoid swelling leading to collagen destruction
and impregnating the tissue with plasma proteins and polysaccharides.

Microscopic picture: connective tissue bundles swell,
rye fibrillarity and merge into a homogeneous dense cartilage-like
mass; cellular elements are compressed and atrophy.

A similar mechanism of development of systemic hyalinosis of connective tissue
is especially common in diseases with immune disorders (rheum-
matic diseases). Hyalinosis can complete fibrinoid changes

Rice. 12. Hyalinosis of the vessels of the spleen.

a - the wall of the central artery of the spleen follicle is represented by homogeneous hyaline-like
masses; 6 - fibrin among hyaline masses when stained by the Weigert method; v- fixation in hyaline
immunoglobulin class G (antibody) immune complexes; fluorescent microscope; G - electro-
nogram: hyaline masses (G) in the wall of argeriola; En - endothelium; NS - arteriole lumen. x 15000.

at the bottom of a chronic stomach ulcer, in the appendix with appendix
cite; is similar to the mechanism of local hyalinosis in the focus of chronic
burning.

As a kind of outcome of sclerosis, hyalinosis is mainly
the same local character: it develops in scars, fibrous adhesions of serous
cavities, vascular wall in atherosclerosis, involutional sclerosis ar-
terium, when organizing a thrombus, in capsules (Fig. 13), tumor stroma, etc.
In these cases, hyalinosis is based on metabolic disorders in the connective
fabrics. A similar mechanism has hyalinosis of necrotic tissues and phi-
brinous overlays.

Appearance organs with hyalinosis are usually preserved. However, in those cases
teas, when the process is pronounced, the tissue becomes pale, dense and
transparent. Hyalinosis can lead to deformation and wrinkling of the organ
(for example, the development of arteriolosclerotic nephrocirrhosis, valvular
rock of the heart).

Rice. 13. Hyalinosis of the liver capsule -
glaze liver (top view).

Exodus in most cases
hyalinosis teas are unfavorable
ny, but possibly resolved
vation of hyaline masses. So,
hyaline in scars, the so-called
keloids, may be subject to
try loosening and resorption
vania. Reverse hyalinosis
the mammary gland, and the spread
draining of hyaline masses
proceeds in conditions of hyperfunction
tion of the glands. Sometimes hyalinis-
the woven fabric becomes licky ..

Functional value hyalinosis is different depending on its location
zation, degree and prevalence. For example, in scars, it may not cause
number of special disorders. Common hyalinosis, on the other hand, leads to sign
significant functional impairments and can have severe consequences
effects, as is observed, for example, with rheumatism, scleroderma,
hypertension, diabetes and other diseases.

Hyalinosis - it is the appearance in cells and tissues of a peculiar substance, heterogeneous in composition and mechanism of its appearance. The basis of hyaline is fibrillar protein, fibrin, immunoglobulins (immune complexes), lipids are mixed here. Based on the differences in the composition of hyaline, there are:

a) simple hyaline - its main part is made up of blood plasma proteins, immunoglobulins;

b) lipogyalin - lipoproteins are found in its composition. Lipogyalin is most commonly found in diabetes mellitus;

c) complex hyaline - cell debris, destroyed connective tissue components and immune complexes are attached to plasma proteins in a significant amount.

Despite its heterogeneity, hyaline, different in localization and origin, has general tinctorial properties when stained with hematoxylin-eosin; when stained according to Van Gieson, picrinophile and gives a positive PIC reaction.

It is more correct to attribute hyalinosis not to dystrophies, but to the outcomes of dystrophies, to the outcomes of alteration, and mainly to alteration of connective tissue. Hyalin can be found in the epithelium, in thrombotic masses, and mainly in connective tissue. Depending on the nature of the deposition of hyaline, there are: vascular hyalinosis and hyalinization of connective tissue. Hyaline is similar in color to fibrinoid. It is oxyphilic, homogeneous and dense. Connective tissue that has undergone hyalinization resembles hyaline cartilage in appearance - vitreous and translucent. Hyalinization of scars or cicatricial thickening of serous integuments, capsule of internal organs (for example, the so-called "glaze" spleen, as an outcome of the transferred perisplenitis) is very typical. In the epithelium, drops of hyaline appear as a result of protein dystrophies (hyaline-drop degeneration of the epithelium of the convoluted tubules of the kidney). In hepatocytes with alcohol intoxication or hepatitis, "Mallory bodies" appear - drops of hyaline in the cytoplasm. In fact, hyaline drops are dead ultrastructures saturated with protein - focal necrosis.

In the mechanism of hyaline changes in connective tissue, a stereotyped mechanism is traced. It consists in structural changes in the connective tissue, which cause an increase in permeability and lead to the insufficiency of proteins that permeate the altered connective tissue.

Hyalinization of connective tissue consists in impregnating protofibrils with proteins, pushing them apart. In the hyalinized tissue, elementary fibrils are disassembled, but the collagen matrix is preserved, the cells are compressed and atrophied. The hyalinization of connective tissue is accelerated by the perversion of the function of fibroblasts and the synthesis of atypical collagen. Factors accelerating hyalinization are numerous: hypoxia, intoxication, decreased iron content, vitamin C deficiency, the effect of immune complexes, genetic defects. Hyalinization of connective tissue is most often focal. However, in some diseases, defined as a pathology of immunity, the effect of IC with damage to connective tissue and subsequent hyalinization becomes systemic. These diseases include systemic scleroderma.

Vascular hyalinosis most often it is systemic. Most often it occurs in arterioles (arteriolosclerosis in hypertension). Capillary hyalinosis is typical for diabetes mellitus. In the arteries, hyalinosis is observed at the locations of atherosclerotic plaques. Local vascular hyalinosis is observed in organs undergoing involution (ovary, thymus).

The most important is systemic vascular hyalinosis in hypertension. The process of hyalinosis, due to its systematic nature, determines the course of hypertension, its progression and the development of complications. The prevalence and degree of damage to arterioles is determined by:

1) the degree of alteration of the vascular wall,

2) the degree of insult,

3) the presence of attachment of immune damage during structural disorganization of the arteriole wall and changes in the antigenic properties of the structures delivering it.

Therefore, with hypertension, two forms of vascular lesions are distinguished.

1. Hyaline arteriolar sclerosis. There is a vasospasm, damage to the glycocalyx of endothelial cells, increased pinocytosis, and the inner layer of the vessel becomes highly permeable to plasma proteins and alpha-lipoproteins. Fibrous structures (basement membranes) are in a state of mucoid swelling. Slow induction occurs with accumulation of plasma proteins. At the same time, smooth muscle cells penetrate into the inner layer from the middle layer through the opening of the basement membranes. They are located circularly, forming the so-called "inner muscle layer". There is a slow formation of hyaline. Picrinophilic fresh proteins become oxyphilic. In addition to hyaline, which is formed by insultation (infiltrative mechanism), hyaline appears in a small number of smooth muscle cells, which begin to synthesize fibrillar proteins. Fibrosis gradually increases, collagenization occurs, followed by sclerosis. Such changes lead to functional inertness of arterioles, narrowing of the lumens fixes arterial pressure at a high level, tissues of this region experience a state of hypoxia due to microcirculation disturbance.

2. Plasma arteriolonecrosis. It occurs with a rapid violation of vascular permeability due to strong and persistent spasms (crises). The effect of catecholamines and glucocorticoids on the endothelium leads to necrosis. There are ruptures of the basement membranes, fibrinoid swelling of fibrous structures. There is an acute insudation, plasmorrhage with death of smooth muscle cells. Against this background, there is a deposit of immune complexes. The hyaline contains ferritin, immunoglobulins M and G, immune complexes with AH of damaged structures and complement. The immune action deepens the damage, fibrinoid necrosis develops. Protein deposits have the character of complex hyaline. This is how plasma arteriolonecrosis or acute plasma impregnation occurs. Necrosis of the vascular wall with complete obliteration of the lumen is accompanied by the cessation of transcapillary exchange and leads to tissue death in the affected region. The result is sclerosis and scarring with vessel obliteration and cicatricial sclerosis of the parenchyma. Such changes represent the morphological substrate of the malignant form of hypertension.

Details

Mesenchymal dystrophies develop as a result of metabolic disorders in the connective tissue and are detected in the structure of organs and vascular walls. With metabolic disorders in connective tissue, mainly in its intercellular substance, metabolic products accumulate, which can be brought with blood and lymph, be the result of perverted synthesis, or appear as a result of disorganization of the basic substance and fibers of connective tissue.

1. Stromal-vascular dysproteinosis

Dystrophies of this type include mucoid swelling, fibrinoid swelling, hyalinosis, amyloidosis.

Often, mucoid swelling, fibrinoid swelling and hyalinosis are successive stages in the disorganization of connective tissue. This process is based on the accumulation of blood plasma products in the main substance as a result of an increase in tissue-vascular permeability ( plasmorrhage), destruction of connective tissue elements and the formation of protein-polysaccharide complexes. Amyloidosis differs in that the composition of the complex formed includes an abnormal protein that amyloidoblasts synthesize.

1) Mucoid swelling

Superficial and reversible disorganization of connective tissue. In this case, the accumulation and redistribution of glycosaminoglycans occurs in the main substance due to an increase in the content of primarily glucuronic acid. Since glycosaminoglycans have increased hydrophilic properties, their accumulation leads to an increase in tissue and vascular permeability. As a result, plasma proteins (mainly globulins) and glycoproteins are mixed with GAGs. Hydration and swelling of the main interstitial substance develop.

Microscopy: the main substance is basophilic. A phenomenon arises metachromasia- a change in the state of the main intermediate substance due to a change in pH with the accumulation of chromotropic substances. Collagen fibers swell and usually retain their bundle structure. They become unstable to the action of collagenase.

Changes may be accompanied by the appearance of lymphocytic, plasma cell and histiocytic infiltrates.

This type of swelling is found in various organs and tissues, but more often in the walls of arteries, heart valves, endocardium, epicardium, that is, where chromotropic substances are found in normal conditions (however, with pathology, their number increases sharply).

Appearance: tissue or organ is preserved.

Causes: hypoxia, infectious and allergic diseases, rheumatic diseases, atherosclerosis, endocrinopathy, etc.

Exodus: twofold. Either complete tissue repair or transition to fibrinoid swelling.

2) Fibrinoid swelling.

Deep and irreversible disorganization of connective tissue, which is based on the destruction of its main substance and fibers, accompanied by a sharp increase in vascular permeability and the formation of fibrinoid. Fibrinoid- a complex substance, it contains proteins and polysaccharides of disintegrating collagen fibers, the main substance and blood plasma, as well as cellular nucleoproteins. Fibrin is an obligatory component.

Microscopy: bundles of collagen fibers, impregnated with plasma, become homogeneous, forming insoluble strong eosinophilic compounds with fibrin. Tissue metachromasia is not expressed or weakly expressed (since the GAGs of the main substance are depolymerized).

Appearance: Externally, organs and tissues change little.

Causes: most often this is a manifestation of infectious-allergic, autoimmune and angioedema reactions. In such cases, the swelling is systemic. Locally fibrinoid swelling can occur with inflammation, especially chronic inflammation.

Exodus: characterized by the development of fibrinoid necrosis, replacement of the destruction focus with connective tissue (sclerosis) or hyalinosis.

Such swelling leads to disruption, sometimes to the cessation of organ function.

3) Hyalinosis

In the connective tissue, homogeneous translucent dense masses are formed, resembling hyaline cartilage. At the same time, the fabric is denser.

Destruction of fibrous structures and an increase in tissue-vascular permeability play a leading role in the development of hyalinosis. Plasmorrhage is associated with tissue impregnation with plasma proteins and their adsorption on altered fibrous structures, followed by precipitation and the formation of hyaline. Smooth muscle cells are involved in the formation of vascular hyaline. Hyalinosis can develop as a result of various processes: plasma impregnation, fibrinoid swelling, inflammation.

Distinguish:

A) vascular hyalinosis

Small arteries and arterioles are mainly affected by hyalinosis. It is preceded by damage to the endothelium, its membrane and smooth muscle cells of the wall and its impregnation with blood plasma.

Microscopy: hyaline is found in the subendothelial space6 it pushes outwards and destroys the elastic plate, the middle membrane becomes thinner, in the phial the arterioles turn into thickened glass tubes with a sharply narrowed or completely closed lumen.

Such hyalinosis is of a systemic nature, however6 it is most pronounced in the kidneys, brain, retina, pancreas, and skin. It is characteristic of hypertension, diabetic microangiopathy and diseases with impaired immunity. As a physiological phenomenon, local arterial hyalinosis is observed in the spleen of adults and the elderly (reflects the functional and morphological features of this organ - blood deposition).

Vascular hyaline- a substance of predominantly hematogenous nature. Guided by the peculiarities of the pathogenesis of vascular hyalinosis, there are:

- simple vascular hyaline

It arises as a result of insudation of unchanged or slightly altered components of blood plasma.This type of hyaline is more common in patients with benign hypertension, atherosclerosis, as well as in healthy people.

- lipogyalin

Contains lipids and beta-lipoproteins. This type of hyaline is often found in diabetes mellitus.

- complex hyaline

It is built from immune complexes, fibrin and collapsing structures of the vascular wall. Such hyaline is typical for patients with immunopathologies, for example, with rheumatic diseases.

B) hyalinosis of the connective tissue itself

It develops, as a rule, as a result of fibrinoid swelling, leading to the destruction of collagen and saturation of the tissue with plasma proteins and polysaccharides.

Hyalinosis of the myometrium is of great clinical importance. After performing a Cesarean section, a scar remains on the uterus, and hyaline is deposited in the cells on the border with the muscle. If a woman gives birth to a second child naturally, then a rupture will occur.

Microscopy: connective tissue bundles lose fibrillarity, and cellular elements turn into a cartilage-like mass.

Hyalinosis can complete fibrinoid changes in the focus of chronic inflammation. Hyalinosis as an outcome of sclerosis is mainly local in nature: it develops in scars, fibrous adhesions of serous cavities, and the vascular wall in atherosclerosis.

Appearance: with severe hyalinosis, the appearance of the organs changes. Hyalinosis of arterioles and small arteries leads to atrophy, deformation and wrinkling of the organ. With hyalinosis of the connective tissue itself, it becomes dense, whitish, translucent.

Exodus: in most cases unfavorable, however, resorption of hyaline masses is also possible.

4) Amyloidosis

It is accompanied by a profound disturbance of protein metabolism, the appearance of an abnormal fibrillar protein and the formation of amyloid in the interstitial tissue and vascular walls.

Amyloid is a glycoprotein, the main component of which is fibrillar proteins (F-component, synthesized by amyloidoblasts). They form fibrils ... Fibrillar proteins amyloid heterogeneous:

a) AA protein: not associated with immunoglobulins, formed from its serum analogue - SAA protein

b) AL protein: associated with immunoglobulins, its precursor is immunoglobulin light chains

c) AF protein: prealbumin is involved in its formation

d) ASC 1 protein - a protein whose precursor is also prealbumin

These fibrillar proteins form complex compounds with blood plasma glucoproteins. This plasma component (P-component) of amyloid is represented by rod-shaped structures.

Both the F and P components are antigenic. The amyloid fibrils and the plasma component enter into compounds in the tissue chondroitin sulfates, and “hematogenous additives” are added to the resulting complex, among which fibrin and immune complexes are of primary importance. All bonds in amyloid are very strong, so the body's enzymes do not act on it.

Classification amyloidosis is based on possible causes, specificity of fibrillar proteins, prevalence, clinical manifestations.

A. For reasons of occurrence:

Primary (idiopathic) amyloidosis

It is characterized by: the absence of a previous or concomitant "causal" disease; damage to mainly mesodermal tissues - CVS, skeletal and smooth muscles, nerves and skin; tendency to form nodular deposits, inconsistency of the colorful reactions of the amyloid substance

Hereditary (genetic, familial) amyloidosis

Hereditary amyloidosis with predominantly kidney damage is characteristic of periodic illness (familial Mediterranean fever), which is more often observed in representatives of ancient peoples (Jews, Armenians, Arabs).

Secondary (acquired) amyloidosis

Unlike other forms, it develops as a complication, and not as an independent disease. Chronic nonspecific inflammatory diseases of the lungs, tuberculosis, osteomyelitis, malignant neoplasms, and rheumatic diseases lead to such amyloidosis.

Such amyloidosis, as a rule, is generalized and occurs most often.

Senile amyloidosis

Typical lesions of the heart, arteries, brain, islets of Langerhans. These changes lead to physical and mental aging degradation. In senile amyloidosis, local forms are most common, although generalized senile amyloidosis is also encountered.

B. By the specificity of fibrillar proteins:

AL amyloidosis

Includes primary (idiopathic) amyloidosis and amyloidosis with "plasma cell dyscrasia", which combines paraproteinemic leukemias, malignant lymphomas, etc.

Always generalized with damage to the heart, lungs and blood vessels.

AA amyloidosis

Covers secondary amyloidosis and McCle and Wales diseases. It is also generalized, but predominantly affects the kidneys.

AF amyloidosis

Hereditary, represented by familial amyloid nephropathy. The peripheral nerves are mainly affected.

ASC 1 - amyloidosis

Senile generalized or systemic with predominant damage to the heart and blood vessels.

B. By prevalence

- generalized form

Primary amyloidosis, amyloidosis with “plasma cell dyscrasia” (AL), secondary amyloidosis and some types of hereditary (AA), senile systemic amyloidosis (ASC 1).

Local amyloidosis

It combines a number of forms of hereditary and senile amyloidosis, as well as local tumor-like amyloidosis.

D. According to clinical manifestations

- cardiopathic

More common in primary and senile systemic amyloidosis.

- nephropathic

With secondary amyloidosis, periodic illness and McCle and Wells disease.

- neuropathic

As a rule, it is hereditary.

Hepatopathic

Epinephropathic

- mixed

Secondary amyloidosis.

APUD amyloidosis

It develops in the organs of the APUD system during the development of tumors (apudomas) in them, as well as in the islets of the pancreas with senile amyloidosis.

Morpho- and pathogenesis of amyloidosis

Sometimes the function of amyloidoblasts is performed by macrophages, plasma cells, fibroblasts, etc. In local forms, cardiomyocytes, smooth muscle cells, keratinocytes can act as amyloidoblasts.

In secondary amyloidosis (excluding amyloidosis in "plasma cell dyscrasia") mutations and the appearance of amyloidoblasts can be associated with prolonged antigenic stimulation.

Cell mutations in "plasma cell dyscrasia" and in tumor amyloidosis are caused by tumor mutagens.

In genetic amyloidosis, we are talking about a gene mutation that can occur at different loci, which is the difference in the composition of amyloid proteins. Probably, similar mechanisms take place in senile amyloidosis.

Since the antigens of the amyloid fibril protein are extremely weak immunogens, mutating cells are not recognized or eliminated. Immunological tolerance to amyloid proteins develops, which leads to the progression of amyloidosis.

The formation of amyloid protein may be associated with:

Reticular fibers (perireticular amyloidosis)

Amyloid falls out along the membranes of blood vessels and glands, as well as the reticular stroma of the parenchymal organs. Characterized by a predominant lesion of the spleen, liver, kidneys, adrenal glands, intestines, intima of small and medium-sized vessels (parenchymal amyloidosis).

Collagen fibers (pericollagen)

Amyloid falls out along the collagen fibers, mainly affecting the adventitia of medium and large vessels, myocardium, striated and smooth muscles, nerves, skin (mesenchymal amyloidosis).

Pathogenesis amyloidosis is complex and ambiguous. The pathogenesis of AA and AL amyloidosis is best studied.

At AA amyloidosis amyloid fibrils are formed from the precursor of the fibrillar amyloid protein entering the macrophage - the SAA protein, which is synthesized in the liver. SAA synthesis stimulates the macrophage mediator interleukin-1, which leads to a sharp increase in SAA in the blood. Under these conditions, macrophages do not completely degrade SAA, and amyloid fibrils are assembled from its fragments and invaginates of the plasma membrane of amyloidoblast. This assembly is stimulated by the amyloid-stimulating factor - ASF, which is found in tissues in the preamyloid stage.

So, the magrophage system plays a leading role in the pathogenesis of AA amyloidosis: it stimulates the enhanced synthesis of SAA, it also participates in the formation of amyloid fibrils from degrading protein fragments.

At AL amyloidosis the serum precursor of amyloid fibril protein are immunoglobulin L-chains. There are two possible mechanisms for the formation of AL fibrils: 1) violation of the degradation of light chains with the formation of fragments capable of aggregation of a fibril; 2) the appearance of light chains with special secondary and tertiary structures during amino acid substitutions.

The synthesis of amyloid fibrils can occur not only in macrophages, but also in plasma and myeloma cells that synthesize paraproteins.

Accordingly, the appearance of amyloidogenic light chains of immunoglobulins, a precursor of amyloid fibrils, is associated with the perverted function of the lymphoid system.

Macro and microscopy

The appearance of the organs depends on the degree of the process. If the deposits are small, the appearance of the organ is little changed. With severe amyloidosis, the organ enlarges, becomes very dense and brittle, and on the cut it has a waxy, greasy appearance.

V spleen amyloid is deposited in the lymphatic follicles (the sago spleen is dense, enlarged, translucent grains on the cut) or evenly throughout the pulp (the sebaceous spleen is enlarged, dense, brown-red, smooth, has a greasy sheen on the cut).

V kidneys amyloid is deposited in the vascular wall, in the capillary loops and mesangia of the glomeruli, in the basement membranes of the tubules and in the stroma. The kidneys become dense, large, greasy. As the process grows, the glomeruli and pyramids are completely replaced by amyloid, connective tissue grows and amyloid wrinkling develops.

V liver deposition of amyloid is observed along the reticular stroma of the lobules. In the walls of blood vessels, ducts, connective tissue of the portal tracts. Hepatocytes shrink and die. The liver is enlarged, dense, looks greasy.

V intestines amyloid falls out along the reticular stroma of the mucous membrane, as well as in the vessel walls of both the mucous membrane and the submucosa. With pronounced amyloidosis, the glandular apparatus of the intestine atrophies.

V heart amyloid is found under the endocardium, in the stroma and vessels of the myocardium, as well as in the epicardium along the veins. Deposition leads to amyloid cardiomegaly. The heart becomes dense, greasy.

Exodus amyloidosis is unfavorable.

2. Stromal-vascular lipidoses

They occur when there are disorders in the metabolism of neutral fats or cholesterol and its esters.

Neutral fats- labile fats that provide the body's energy supply.

Obesity- an increase in the amount of neutral fats in fat depots, which is of a general nature. It is expressed in the abundant deposition of fat in the subcutaneous tissue, omentum, mesentery. mediastinum, epicardium. Adipose tissue also appears where it is normally absent, for example, in the stroma of the myocardium, pancreas.

Classification is based on different principles:

A. On the etiological basis:

Primary form

Its cause is unknown, which is why it is called idiopathic.

Secondary form

Represented by the following types:

Alimentary, the cause of which is physical inactivity and unbalanced nutrition

Cerebral, developing with trauma, tumors, a number of neurotropic infections

Endocrine-syndromes Itsenko-Cushing, Frohlich

Hereditary - Lawrence-Moon-Biedl syndrome, Gierke's disease

B. By external manifestations:

Symmetric type

Fats are deposited evenly in different parts of the body.

Accumulation in the subcutaneous tissue of the face, occiput, neck, upper shoulder girdle, mammary glands.

Fat is deposited in the subcutaneous tissue of the abdomen in the form of an apron

In the area of the thighs and legs

B. Overweight:

I degree - 20-29% overweight

II degree - 30-49%

III degree - 50-99%

IV degree - 100% or more

D. According to the characteristics of morphological changes

The number of adipocytes and their size are taken into account.

Hypertrophic type

Fat cells are enlarged and contain several times more triglycerides than normal ones. The number of adipocytes does not change. Adipocytes are insensitive to insulin, but highly sensitive to lipolytic hormones.

Hyperplastic type

The number of adipocytes increases. The function of adipocytes is not impaired, there are no metabolic changes, the course of the disease is benign.

Causes and mechanisms of development

Unbalanced nutrition, physical inactivity, violation of the central nervous system, endocrine regulation, hereditary factors are of great importance.

The direct mechanism of obesity lies in the imbalance of lipogenesis and lipolysis in the fat cell in favor of lipogenesis.

Exodus: seldom favorable.

Disorders of the metabolism of cholesterol and its esters.

Such disorders underlie atherosclerosis. At the same time, cholesterol and its esters accumulate in the intima of the arteries, but also low-density beta-lipoproteins and blood plasma proteins, which is facilitated by an increase in vascular permeability.

The accumulation leads to the destruction of the intima.

As a result, fatty protein detritus forms in the intima, connective tissue grows, and a fibrous plaque forms, narrowing the lumen of the vessel.

3. Stromal-vascular carbohydrate dystrophies

May be associated with an imbalance of glycoproteins and glycosaminoglycans.

Slime tissue- dystrophy associated with impaired glycoprotein metabolism. Chromotropic substances are released from the bonds with proteins and accumulate in the intermediate substance. In contrast to mucoid swelling, collagen fibers are replaced by a mucoid mass. Connective tissue, organ stroma, adipose tissue, cartilage become translucent, mucoid, and their cells become stellate.

Cause: most often due to dysfunction of endocrine jellies, exhaustion (for example, myxedema, mucous edema, mucous connective tissues with cachexia).

Exodus: The process may be reversible, but its progression leads to colliquation and necrosis.

Hyalinosis of arterioles is a characteristic phenomenon in the pathological picture of hypertension.

Hyaline masses are deposited in the inner lining of the arterioles under the endothelial cover between the inner and outer sheets of the elastic plate; the middle muscular membrane of the vessels is pushed aside by hyaline masses outward. The deposition of hyaline masses leads to a strong thickening of the vessel walls, narrowing of the vascular lumen, and sometimes to its complete closure. It is possible that hyaline is formed in the vessel walls as a result of coagulation of a liquid protein mass entering the inner layers of the vessel from the bloodstream. From this point of view, hyalinosis can be considered as an outcome of protein soaking. Hyaline masses are more homogeneous and dense. Reactive phenomena around the hyaline masses accumulated in the walls of blood vessels are usually not observed.

Hyalinosis of arterioles occurs not only in patients with hypertension. In a large number of cases and in a weak form, it can be found in elderly people who have not suffered from hypertension. Hyalinosis of arterioles affects different vascular regions far from the same. It is most pronounced in the arteries of the spleen, moreover, not only in patients with hypertension, but also in elderly people with normal pressure. Very often and to a pronounced degree, it occurs with hypertension in the vessels of the kidneys, adrenal glands, and pancreas. If hyalinosis of renal arterioles in hypertension occurs in 97% of cases, then among normotonics it is observed only in 2%. Therefore, hyalinosis of renal arterioles is a phenomenon quite characteristic of hypertension.

Protein masses entering the thickness of the vascular walls during hypertension can be further absorbed. Thus, protein impregnation at first, if it has not reached a large extent, is a reversible process. This extremely important circumstance should serve as an additional incentive for vigorous treatment of hypertensive patients.

But most often, protein impregnation and hyalinosis of arterioles in hypertension are accompanied by destructive and sclerotic changes. Arteriolosclerosis is a common outcome of later stages of high blood pressure. It leads to subsequent disorders of blood supply and nutrition of tissues and organs, further narrowing the bloodstream in addition to the narrowing that is created as a result of hypertensive changes in vascular tone.

Protein impregnation and hyalinosis of arterioles can often be observed simultaneously with hypertension, and in different organs these changes can be in different phases of their development, now more recent, now later. This suggests that plasma impregnation, hyalinosis and arteriolosclerosis are forms of the same process, occurring in the form of repeated outbreaks, "and each time new parts of the arterial network are involved in the process." In some organs, hyalinosis is mainly observed, in others - plasma impregnation, in others - their combination.

The article was prepared and edited by: surgeon

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Nowadays, all kinds of diseases are found in medicine. Diseases of the connective tissue, in particular hyalinosis, are not an exception. This is an overgrowth of hyaline in the connective tissue, forming dense masses that resemble cartilage. This pathology is observed in various diseases, for example, hypertension, lupus erythematosus, atherosclerosis, diabetes and so on. It is characterized by an increase in the permeability of blood vessels and body tissues, as well as the impregnation of tissues with plasma proteins. At the same time, human vessels have a narrowed lumen and resemble dense tubes in their structure. This process is irreversible, but in some cases partial resorption of hyaline is possible. In some cases, this pathology can be attributed to the physiological process of the body in old and mature age. This can be, for example, hyalinosis of the vessels of the spleen, etc.

Defining the problem

Hyalinosis is a pathology in which hyaline (fibrillar protein) is deposited in the walls of blood vessels and connective tissue in the form of dense translucent masses. Hyalin, which is a protein, contains fibrin, plasma proteins, lipids and immunoglobulins. It is unaffected by acids, enzymes and alkalis. Currently, hyalinosis is a disease that is very common and is observed in most of the elderly people who have hypertension, hypertension or diabetes mellitus. The vessels are more affected, the connective tissue suffers to a lesser extent. With this pathology, the tissue becomes denser, therefore, the ailment is referred to as a type of sclerosis.

The emergence and development of pathology

Morphogenesis of hyalinosis is very complex and depends on the type of pathology (vessels, connective tissue or serous membranes). The main thing in its formation is the destruction of cells of fibrous structures and leaks of blood vessels as a result of pathological processes in the immune and nervous system, metabolism. In this case, hyaline is formed from the smooth muscle cells of the vessel walls. In most cases, it can appear as a result of various diseases: hypertension, rheumatism, inflammatory processes, necrosis or sclerosis. As a result of sclerosis, this pathology is formed in scars and adhesions, vascular walls, or is involved in the appearance of blood clots. This happens due to metabolic disorders in the connective tissue. There is also, in which the capsule increases in volume and is saturated with proteins.

Vascular hyalinosis

Small arteries and areoles are exposed to this pathology. It arises as a result of the destruction of the endothelium and cell membranes that line the walls of blood vessels. In this case, a thinning of the vascular membranes occurs, they turn into thickened tubes with a narrowed or closed lumen. This process is most often observed in the brain, kidneys, pancreas and is typical for hypertension, diabetes mellitus and disorders of the human immune system. As a physiological process occurs in the elderly in the spleen.

Types of vascular hyalinosis

In medicine, it is customary to distinguish three types of vascular hyalinosis:

Simple, characterized by the appearance due to the release of plasma from the bloodstream. This phenomenon is often observed in atherosclerosis and hypertension.
Lipogyalin, which contains lipids and is characteristic of people who suffer from diabetes.
Complex hyalinosis, which consists of immunoglobulin, fibrin and is typical for people with diseases of the immune system, rheumatism.

As a result, hyalinosis develops with hypertension, becomes wrinkled and has a fine-grained surface.

Effects

With vascular hyalinosis, the consequences are irreversible, so the prognosis is poor. Pathology leads to deformation and atrophy of the organ, as a result of which its failure develops, hemorrhages appear (stroke). In the case of hyalinosis of connective tissue, partial resorption of hyaline is possible, therefore, to some extent, the pathological process can be reversible. This applies, for example, to the mammary glands. This pathology can also lead to organ failure. As for scars, there are no special disorders, but only a cosmetic defect.

Clinical picture

Vascular hyalinosis is not clinically manifested, with the exception of lesions of the vessels of the fundus, which can be determined using ophthalmoscopy. At the same time, small arteries look thickened and curved. The connective tissue that is affected by this ailment is dense, inelastic, cream-colored. This is clearly visible in keloid scars and heart valves. With the defeat of the serous membranes, a thickening of the tissue is observed, it acquires a milky hue. If there is either a liver, then these organs will look as if they were doused with icing sugar. In this case, the disease will be called glazed spleen or glazed liver.

Invisible picture of pathology

With this pathology, there is a thickening of the walls of the arteries due to the accumulation of hyaline masses in them, which partially or completely cover the lumen. In this case, the kidney tangles are replaced by this mass. With pathologies of connective tissue and serous membranes, the presence of hyaline masses with blood glycoproteins is visible. The narrowing of the lumen of the vessels leads to barotrauma, which is not prevented by the contraction of the areola, since it will lose this ability. This leads to the saturation of areas of tissue that is supplied with blood, plasma, so it loses its function. Thus, hyalinosis of the renal tangles gradually develops, chronic renal failure and retinopathy appear, which leads to complete blindness. Since hyalinosis is also a pathology in the connective tissue, if it occurs in the valves of the heart, this contributes to their deformation and leads to their failure. The pathology of the serous membranes is most often detected during operations or autopsy. If it is found in the spleen or liver, it can lead to filling of these organs with blood, stretching of their capsule and the appearance of pain. Lipoids and salts are often deposited in the tissue as a result of its breakdown into simple chemical compounds.

Diagnostics

To identify hyaline, eosin staining is performed, while it will have a pink color. The Van Gieson stain will have a result depending on the age of the patient (yellow to red). Here fuchsin and picric acid act as dyes. Thrombotic masses and inflammatory exudate testify to the appearance of hyaline in dead tissue. For the purpose of diagnosis, histological studies are carried out, while hyalinosis is observed in the connective tissue. Tissue necrosis occurs, which is often accompanied by rupture of the vascular wall, the appearance of hemorrhages and thrombosis. Under a microscope, one can detect swelling, atrophy of cells, loss of elasticity of blood vessels, hardening of organs, and a change in their color. Externally, the tissues that are affected by hyalinosis are not changed.

Differential diagnosis

It is necessary to distinguish between physiological hyalinosis, which appears as a result of aging of the body, and a pathological process. The transformation of dead tissue and secretion products is also similar to this ailment. It must be remembered that pathological processes in the uterus and mammary glands are reversible, since the functions of these organs are enhanced.

Forecast

The outcome of segmental hyalinosis is renal failure. In rare cases, nephrotic syndrome is observed, which is inherited. Nephritis is often associated with abnormalities in the development of the kidneys. Children mainly die due to the failure of this organ.

Thus, hyalinosis is a change in connective tissue that leads to pathologies and is a consequence of various diseases. Also, this process is observed during aging of the body and is of a physiological nature.