Allergy and cancer relationship: research, observations of scientists

Allergies and cancer are among the most common and severe diseases. Their treatment presents significant difficulties for physicians around the world. WHO statistics indicate a steady increase in the number of allergy sufferers. Oncologists are forced to admit that cancer remains a fatal disease. The search for new approaches to the diagnosis and treatment of these diseases is a priority area of ​​medical science.

The role of the immune system in allergies and cancer

The function of the immune system is to control and maintain the genetic identity of the organism. Immune defense mechanisms are aimed at recognizing a foreign agent and neutralizing it. In addition to external antigens, cells of its own tissues are also removed from the body, which are perceived as "not our own" when they are already "worked out" or are malignant.

Tumors can develop when the immune system, for some reason, ignores the growth of malignant neoplasms and cannot cope with their destruction. It is known that the immune response to tumor antigens is poorly expressed and cannot prevent neoplastic cell transformation.

Allergic manifestations also occur when the immune system "malfunctions", but of the opposite nature. In this case, immune hyperactivity is pathological. When an allergen that is not infectious enters the body, the immune response leads to damage to its own tissues.

The mechanisms of allergic reactions are well understood and they can develop in four different "scenarios" called allergy types. With hyperactivity, a complex multistep cascade of responses to a foreign antigen is triggered with the formation specific antibodies, activation of immunocompetent cells (T-cells, their subpopulations, B-lyphocytes, etc.) and the release of active mediators. In particular, histamine and interleukins, the role of which is now being actively studied.

It should be noted that a certain place in the anticancer defense is given to immunoglobulin E (IgE), which is synthesized in the case of an immediate type of allergy. The role of cellular immunity, the participation of subpopulations of cytotoxic T-lymphocytes, T-helpers and other immunocompetent cells in suppressing the proliferation of cancer cells is also discussed.

Information on the relationship between allergies and cancer

In recent years, many scientific publications have appeared on the relationship between allergic and oncological diseases. Provides information about both positive and negative interactions.

Research and observation	Details
Research by Canadian scientists	Canadian scientists have identified a link between allergy (hay fever) and pancreatic cancer (adenocarcinoma). As a result of studying the anamnesis of 650 people, it was found that people suffering from polynosis (mainly men) develop pancreatic cancer 57% less often than nonatopics.
American Canadian study	A joint US-Canadian large-scale screening study over the past 20 years of the past millennium showed that atopics died from cancer 10% less often than people who did not have allergies.
Observations of American doctors	The results of observations of American doctors say that patients with glioma (primary brain tumor) allergy occurs less frequently (in 35% of cases) than in healthy people from the control group (in 45% cases);
Women with asthma and cancer	Women with asthma are 30% less likely to develop ovarian cancer than non-allergic women. However, asthma can lead to lung cancer.
Children with allergies and cancer	Children with allergies are less likely to develop leukemia, skin and lung cancer.
Research by Danish Scientists	Danish scientists have published data on allergen tests of 17 thousand. people held in the last 20 years. It was found that in persons with hypersensitivity, the risk of skin and breast cancer was reduced. However, among this category of surveyed, there was an increase in the incidence of bladder cancer.
Allergies and blood cancer	The predisposition to blood cancer in atopics (sensitivity to pollen) was noted as a result of a mass survey of the population in the United States.

About cellular immune mechanisms

Russian scientists from the Siberian Branch of the Research Institute of Oncology have obtained interesting results in a comparative analysis of cellular and molecular immune mechanisms in patients with allergy and cancer. The dynamics of changes in T-cell subpopulations in lung cancer and asthma was studied.

• Controlled the number of T-helpers 1. These cells stimulate the cellular response by triggering killer T cells that attack cancer cells and other foreign agents (viruses, bacteria).
• Determined the level of T-helpers 2, which activate B-lyphocytes. These immunocompetent cells form a humoral response (the formation of specific antibodies), which provokes the development of allergies and affects the bacteria in the blood.
• The number of T-regulatory lymphocytes, which control the ratio of T-helpers 1 and T-helpers 2, was recorded.

It was found that in allergy, the population of T-helpers 2 increases, which is due to a decrease in the effect of T-regulators. In lung cancer, an increase in the population of T-regulators was noted, which clinicians associate with a poor prognosis. These data provide reliable evidence of the connection between allergic and oncological processes at the level of intercellular interaction.

The role of immunoglobulin E

Scientists at the University of Vienna in experimental work on laboratory animals have shown that IgE reduces the proliferation of cancer cells. In animals with cancer, tumor proliferation was stopped by the administration of a "vaccine" obtained from allergic rodents. However, some laboratory animals developed an acute allergic reaction. It is known that the production of IgE is controlled by T-helpers 2. Scientists have set themselves the task of finding ways to regulate the T-helper 2 population to reduce side effects. Now, in the future plans of the researchers is the creation of a biologically active targeted drug capable of suppressing the development of malignant neoplasms.

Antihistamines and myeloid suppressor cells.
In recent years, the attention of scientists has been directed to the study of the population of myeloid suppressor cells (MDSCs), which are produced by the bone marrow. These cells have pronounced immunosuppressive properties. Their number increases with chronic infectious and oncological diseases. The accumulation of MDSCs cells in the tumor strongly suppresses the immune response and indicates a poor prognosis.

Group of experimental animals	Drug name	the effect
Mice with allergies	Cetirizine, Cimetidine	Reducing the suppressive effect of MDSCs
Mice with cancer	Cimetidine + Suppressor Cell Suspension (MDSCs)	Decreased suppressive effect of MDSCs and slowed tumor growth

The same laboratory tested the blood of people with allergies for the presence of MDSCs-myeloid suppressor cells. It has been shown that in atopics with high histamine levels, the population of these cells is significantly increased. This made it possible to make an assumption about the possible anticancer effect of antihistamines based on the suppression of the suppressive action of myeloid suppressor cells. The mechanisms of interaction between these drugs and immunocompetent cells are multistage and multidirectional. The use of antihistamines for immunotherapy and cancer prevention is at an early stage of study.

Interleukins

A promising area of ​​molecular immunology is the study of the properties of interleukins (IL) - active factors secreted by lymphocytes in the immune response under various pathological conditions. Domestic immunologists conducted a number of studies of IL25 and IL17, which characterize their structure and describe their biological effects. It is noted that interleukins 17 and 25 are distinguished by a wide and varied spectrum of action at various stages of immunological processes. IL25 plays a leading role in the formation of atopy, and also participates in antitumor protection. Information about the features of the activity of inteleukins makes it possible to consider the question of the relationship between allergies and oncological diseases.

On the value of research

Therefore, the study of cellular and molecular mechanisms opens up prospects for obtaining a new generation of drugs for the treatment and prevention of these serious diseases.