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Immunopathogenesis of tissue helminthiases



Helminth larvae formed after infection of a person from the intestines penetrate into the blood and are hematogenously carried to organs, where they can remain viable for many years, determining the clinical picture of the disease. In some cases, re-migration of larvae is possible.

Tissue migration is associated with serious pathological changes in the human body, both specific, characteristic of a particular pathogen, and non-specific, common to all helminthiases. The pathogenicity of helminths is higher in zoonotic helminths, which are not evolutionarily adapted to humans, and also in the larval stages of parasites.

Regardless of the type of pathogen, during the migration of tissue helminths, allergic reactions of the body to metabolic products of larvae occur. The migration stage of toxocariasis is accompanied by eosinophilic infiltrates of the lungs, liver, polymorphic skin rashes, hypereosinophilia. Severe allergic reactions up to the development of an infectious toxic shock are observed in case of violation of the integrity of echinococcal cysts as a result of trauma or during surgery. Severe allergic edema of subcutaneous fat, as well as the development of severe immunopathological reactions accompany the course of trichinosis. The development of allergic reactions is accompanied by the development of immunosuppression.

The activity of the immune process during helminthiases reflects the eosinophilic reaction: a generalized reaction with hepereosinophilia of the blood indicates a favorable course of the pathological process, and localized tissue or organ eosinophilic infiltration often indicates severe cytopathic processes. The immune response develops according to the T-cell type. Under the action of interleukin-5 (IL-5), secreted by type 2 helper T-lymphocytes, eosinophils, which are the main effector cells that protect the body from large parasites inaccessible to immunocompetent cells, are stimulated.
Eosinophils carry out a distant effect on mature helminths and their larvae due to the release of lysosomal enzymes, free radicals, stimulation of the secretion of class E immunoglobulins (IgE), which leads to the death of parasites.

The development of specific immunity in helminthiases and its tension depend on the general condition of the host organism, its hormonal status, and genotype. The specific immunity that develops under the influence of helminth antigens, its metabolic products and decay in the event of the death of a parasite is not sterile: it only helps to limit the number of helminths, and not their destruction.

The effectiveness of specific immunity is partly due to the type of parasite. Trichinella is known to stimulate strong protective immunity. Echinococcus larvae, forming a cyst, are protected from the action of the immune system and, as a rule, do not cause significant eosinophilia. Specific immunity in toxocariasis reduces the risk of repeated invasions, although it does not completely exclude them, at the same time, those infected with toxocaras develop immunosuppression, documented by a sharp decrease in post-vaccination titers for live and killed vaccines and toxoids (measles vaccines, mumps, DTP, etc.) .

Specific antibodies are used as laboratory markers of the corresponding invasion.

In some cases, they describe the innate, genetically determined, resistance of a person to helminth invasion.

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Immunopathogenesis of tissue helminthiases

  1. Treatment of tissue helminthiases
    Treatment of patients with tissue helminthiases, regardless of severity, is carried out in a hospital. In the acute period of the disease, with severe forms of trichinosis, toxocariasis, cysticercosis, complicated forms of echinococcosis (rupture or suppuration of an echinococcal cyst), bed rest is prescribed. A complete diet enriched with vitamins is shown. Etiotropic therapy. It is indicated for all forms of tissue
  2. Laboratory diagnosis of tissue helminthiases
    Laboratory methods for tissue helminthiases, as a rule, are crucial for making and registering a diagnosis and selecting rational etiotropic therapy. In connection with the peculiarities of the pathogenesis of the described diseases, the methods of coprological research used to diagnose intestinal helminthiases are not informative. Currently, there are parasitological, immunological, including
  3. HELMINTHIASES CAUSED BY TISSUE NEMATODES
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  4. Clinical and epidemiological characteristics of certain types of tissue helminthiases
    Toxocarosis (Toxocarosis) - zoonotic geohelminthiasis caused by toxocar larvae, which occurs with damage to internal organs and eyes. Etiology. The causative agents of toxocariasis are the larvae of nematodes of the family Anisakidae of the genus Toxocara: Toxocara canis (a helminth that parasitizes in canines, which is most important in human pathology) and Toxocara mystax (helminth
  5. Antonov M.M .. Tissue helminthiases in adults and children (epidemiology, clinic, diagnosis, treatment, prevention), 2004

  6. Tissue destruction and tissue hypoxia syndrome
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  7. Diseases caused by the 4th type of immunopathological reactions. Immunopathogenesis. Nosological forms of diseases
    The 4th type of immunopathological reactions is associated with a delayed-type hypersensitivity reaction - HRT, i.e. with reactions of type 1 T-helpers and HRT T-effectors. In this case, type IV reactions occur no earlier than 12 hours. The prototype of this form of response is a tuberculin test, still used in the clinic of infectious diseases. Sequence of events leading to
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  9. Tissue hypoxia
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  10. Definition of tissue Po in the fetus
    The oxygen tension (Po) in the fetal tissues can be determined by the polarographic method during childbirth in the absence of the fetal bladder. This allows for early diagnosis of intrauterine hypoxia (acute and chronic) of the fetus. Intra- and percutaneous polarographic methods for determining PQ in tissues can be used. For intradermal determination of PQ, open microelectrodes are used, which
  11. Deafferentation and denervation hypersensitivity. Tissue deprivation. Inhibition and hyperactivity
    In clinical neurology, the origin of certain motor disorders (sensory ataxia or kinesthetic apraxia, afferent motor aphasia or cortical dysarthria) has long been known for the mechanism of deafferentation. And here, believes V.A. Karlov (1996), for a deeper understanding of the problem, it is useful to use the phylontogenetic aspect. In children, as you know, takes place
  12. Helminthiasis
    Helminthiasis is a group of diseases caused by parasitic worms - helminths. Over 250 types of helminths have been described in humans, of which in Russia representatives of the class of roundworms are of greatest importance: causative agents of ascariasis, hookworm infections, trichinosis, enterobiasis; trichocephalosis; class of tapeworms: teniosis, diphyllobothriasis, echinococcosis; class of flukes:
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