Productive (or proliferative) inflammation is the body's response. At the appearance of which a particular phase prevails. That is, in this case, the proliferation of cells of histiogenic and hematogenous origin predominates. The main cell in the area of productive inflammation is considered to be a monocyte that enters the tissue directly from the bloodstream; in the tissues, the monocyte transforms into a macrophage.
Macrophage
The main function of a macrophage is phagocytosis. On its surface there are many different receptors that are necessary to capture viruses, fungi, bacteria, immunoglobulins. Phagocytosis during proliferative inflammation may not always be complete, that is, it does not end with the absolute digestion of a foreign agent. Viruses and microbial cells inside macrophages survive, multiply, which is why the process becomes chronic. In addition to macrophages during proliferative inflammation, oftenother cells are found. These include lymphocytes, eosinophils, plasma cells, mast cells, single neutrophils.
During cell proliferation, cellular diffuse or focal infiltrates are formed.
Varieties
The problem can develop in any organ of the body and on any tissue. There are the following types of proliferative inflammation:
- interstitial (interstitial);
- productive with the formation of polyps, genital warts;
- granulomatous.
Let's consider them separately.
Interstitial
Interstitial (or interstitial) is a type of proliferative inflammation in which a diffuse or focal cellular inflammatory infiltrate is formed in the stroma of the heart, liver, kidneys, lungs. The infiltrate is represented by lymphocytes, plasma cells, macrophages, eosinophils, single mast cells, destroyed parenchyma elements, rare neutrophils.
In the parenchymal elements, pronounced dystrophic, in some cases necrobiotic changes are determined. The result of interstitial inflammation will be interstitial fibrosis, which is the proliferation of connective tissues.
With polyps and genital warts
The proliferative phase of inflammation with the formation of polyps, as well as genital warts, is characterized by a chronic course. It is localized on the mucous membrane. Separate areas of hyperplasia are formed on the mucous membranes of various organs, as well as epithelial growths in the form of polyps, in which the connective tissue baseinfiltrated with macrophages, lymphocytes, plasma cells and others.
Localized most often on the mucous membrane of the nose, stomach, uterus, intestines, bronchi. In the case of localization of inflammation at the junction of a single-layer cylindrical and stratified squamous epithelium, the so-called condylomas are formed. These formations often appear in the anus, as well as on the genitals. In chronic proliferative inflammation, frequent condyloma is genital warts, which is caused by papillomavirus. It is considered a risk factor for the development of squamous cell carcinoma.
Granulomatous
Granulomatous is another variant of productive (proliferative) inflammation. During which the main morphological substrate is considered to be a granuloma, where cells predominate: macrophages, as well as their derivatives (giant cells, epithelioid).
Morphogenesis of granulomas has four successive phases. These include the following:
- accumulation of young monocytes in the lesion;
- maturation of these cells in a macrophage with the formation of a macrophage granuloma;
- further maturation and transformation of monocytes and macrophages into an epithelioid cell and the formation of an epithelioid cell granuloma;
- transformation of an epithelioid cell into a Pirogov-Langhans giant cell (foreign body cell) and the formation of giant cell granulomas.
It should be noted that the phagocytic activity of the granuloma cell as it matures graduallydeclining.
The diameter of granulomas is about 1-2 mm, most often they are visible only with a microscope. In the central region of the granuloma, one can see tissue detritus, which is formed as a result of tissue necrosis and in which the causative agent of the underlying disease can be detected, if in this case there is an infectious process. Macrophages are located on the periphery of necrosis. There are also giant, epithelioid cells, among them there may also be plasma cells, neutrophils, lymphocytes, eosinophils.
Granulomatous diseases
Among such diseases in the form of proliferative inflammation, 4 groups are distinguished. These include:
- infectious etiology, which should include rheumatism, typhus and typhoid fever, rabies, brucellosis, tularemia, viral encephalitis, yersineosis, actinomycosis, syphilis, leprosy, schistosomiasis, tuberculosis, scleroma, glanders and others;
- non-infectious etiology, which should include gout, silicosis, anthracosis, talcosis, asbestosis, berylliosis, aluminosis;
- drug ailments, e.g. drug-induced hepatitis, oleogranulomatous disease;
- diseases of unknown etiology: Crohn's disease, sarcoidosis, Horton's disease, Wegener's granulomatosis, rheumatoid arthritis, xanthogranulomatous pyelonephritis.
Absolutely all granulomas have an infectious etiology, despite the differences, they are similar in morphology. It is also worth noting that in all situations, infectious granulomas appear as clusters.cells having a monocyte-macrophage nature. In some granulomas, lymphocytes, neutrophils, plasma cells are formed, with helminthiasis many eosinophils appear.
The only exception will be granulomas in the case of tuberculosis, syphilis, scleroma, glanders, leprosy. In these diseases with proliferative inflammation, these granulomas have specific features that are characteristic only of a certain pathogen. And this allows us to attribute this group of diseases to the group of specific granulomatosis. Or specific inflammation.
In the morphological concept for a specific inflammation, the formation of several specific granulomas will be characteristic. which have a characteristic structure. It may differ depending on the main pathogen - the cause of proliferative inflammation. Thus, the cellular composition, as well as the location of the cells directly in the granuloma, is quite specific for each pathogen.
Tuberculosis
The inflammatory process in tuberculosis, that is, Mycobacterium tuberculosis can cause three types of tissue reaction: exudative, alterative, and proliferative.
As for alternative inflammation, it often develops as a result of hypoergy, in the case of a decrease in the defenses of the human body. This inflammation is morphologically manifested by caseous necrosis.
Exudative type of inflammation develops as a result of existing hyperergy (in case ofhypersensitivity to mycobacterium toxins, antigens). Morphologically, accumulation manifests itself in the lesion of fibrinous, serous or mixed exudate, which later also undergoes caseous necrosis.
Proliferative inflammation, pathology says, develops in the condition of a specific tuberculous immune system. The morphological manifestation in this case will be the formation of the so-called tuberculous granulomas, presented in the form of millet grains.
Tuberculosis granuloma
So, we have analyzed what characterizes proliferative inflammation. Now it is worth considering separately some cases in which it manifests itself.
Tuberculosis granuloma has a characteristic structure: in its central region there is a focus of the so-called caseous necrosis, behind which is a shaft of radially localized (that is, elongated along the length to the periphery from the center) epithelioid cells. Behind these cells, giant single Pirogov-Langhans cells are visible.
It should also be noted that on the periphery of such a granuloma there is a shaft of lymphocytes. In a large number of these typical cells, plasma cells, as well as macrophages, can still be found in a small amount. In addition, a thin network consisting of argyrophilic fibers is also revealed here. As for the blood vessels, they are not found here. Mycobacterium tuberculosis can be detected in these giant cells in the case of Ziehl-Neelsen staining.
Inflammatory process in syphilis
The inflammatory process in syphilis at different periods will reflect a different tissue reaction to pale treponema: as a rule, primary, secondary, and also tertiary periods are distinguished in case of syphilis.
In the case of primary syphilis, the so-called productive-infiltrative reaction develops in the area of treponema penetration.
During the secondary, a strongly pronounced exudative reaction is observed, contributing to the generalization of the pathogen, In the case of the tertiary period of syphilis, the productive-necrotic reaction will be presented in the form of a syphilitic granuloma, as well as gummous infiltrates.
More about Syphilitic Granuloma
Syphilitic granuloma in the field of medicine also has a short name "gumma". In this granuloma, as in the case of tuberculosis, caseous necrosis is found in the center, but in this situation it will be larger in size.
From necrosis on the periphery is a large number of lymphocytes, fibroblasts, and plasma cells. In a small amount, macrophages, giant cells, and epithelioid cells may be present here. In this case, the proliferation of connective tissues is considered characteristic (this is due to the rapid proliferation of fibroblasts), which form a kind of capsules, as well as a large number of blood vessels.
Quite rarely, among these cells, specialists can identify the so-called pale treponemasilver plating according to Levaditi. Gumma is typical for the tertiary period of syphilis, which begins to develop after a few years (5 or more) from the time of its infection.
In various organs: skin, liver, bones, brain, knots 0.3-1.0 cm in diameter are formed within one decade. In the context of these nodes, a certain jelly-like mass of a yellowish hue is distinguished, which in its appearance resembles gum arabic glue, from which the name "gum" came from.
Gumous infiltration
In addition to these gums, gummous infiltration can also develop in the tertiary period of syphilis. The infiltrate is represented by the same cells, that is, sclerosis, vascular proliferation. The infiltrate is localized most often in the ascending heart, as well as the aortic arch, and is called "syphilitic mesoaortitis".
He, located in the central and outer shell of the cardiac aorta, gradually destroys its elastic framework, and connective tissue begins to grow in place of the elastic fibers. Because of all this, the inner shell on the aorta becomes uneven and wrinkled with a large number of cicatricial retractions, bulges, outwardly resembling shagreen skin.
Conclusion
As we noted earlier, proliferative (or productive) inflammation is characterized by cell proliferation. Exudative and alterative changes recede only into the background. The entire course of this inflammatory process canbe acute, but most often chronic.
