Allergies and intolerances - our immune system
Our immune system is a combination of cells, tissues, organs that fight together against "foreign invaders" attacking our bodies. These are mainly microbes, organisms that cause small infections such as bacteria, viruses, parasites and fungi. Since our organism could be an excellent environment for countless microbes, they regularly try to break into our body. When our body hits a false target, it can be the source of countless unfavorable processes, such as allergies or AIDS. Our immune system is able to recognize and remember millions of diseases, it is able to produce secretions and cells that defeat intruders. The secret to success based on a complicated and highly dynamic communication system. Millions of cells work together like a cloud of bees while swarming, transmitting information between each other back and forth. When immune cells receive an alarm, they change and begin to produce strong chemicals (messenger molecules). A healthy immune system is able to distinguish the body's own cells from strangers. Normally, our body correctly recognizes substances and organisms that are harmless, but if we recognize it as harmful, the response of our immune system begins. Anything that can trigger an immune response is called antigen. Occasionally, our organism can misjudged itself and launch an attack on its own cells, which we call autoimmune disease. It also misunderstands harmless molecules such as pollen. The result is allergies and any kind of antigen called an allergen.
Our primary lymphatic organs are responsible for the production of B and T-cells, B-cell are produced in the bone marrow and cell T-cells are produced in the thymus, after which the secondary lymphatic organs migrate. B-cells are responsible for antibody production, which is responsible for hunting down antigens that circulating in the blood. Each B cell is programmed to produce specific antibodies, so one B lymphocyte (lymphatic cell) will produce antibodies that inhibit the virus that causes colds, while another will attack the bacterium responsible for pneumonia. An antigen matches its antibody as a key to its lock and, when connected, marks the antigen for destruction. Antibodies belong to the group of immunoglobulins, from here there also comes the naming of different types of antibodies, such as the antibody IgE (Immunoglobulin E), whose work is to protect against parasitic infection, although unfortunately it often provokes an allergic reaction. T lymphocytes play a role in the recognition of already infected cells. They can act in two ways, either indirectly triggering an immune response or directly attacking the infected cell. The assistive T cells are involved in the first version by coordinating the immune response and cytotoxic or killer T cellejecles are involved in the direct attack. Of course, our immune system is much more complex than that, but I think that might be enough to help us understand how allergies work.
The allergic reaction
Most of our allergic reactions are due to a faulty distress signal when a harmless substance is misunderstood by our body and triggers an immune reaction against it. Allergy most often develops in the first 3months of our lives, but sometimes it can develop even at the moment of birth, of course this is especially possible with hereditary allergies. In many cases, it happens that our allergies do not accompany us throughout our lives, it is possible that we simply grow out from it.
The immunological basis for the development of allergies is that when a foreign substance enters the organized, it is presented by the body to a naïve T-cell called a naïve T-cell, which, as a result, turns into a helping T-cell. If this assistive T-cell becomes a Th2 cell, it means that our immune system has recorded the foreign substance that has entered our body as an allergen. Th2-type assistive cells are responsible for the release of chemicals responsible for inducing areas of the immune system known as allergic reactions. That's why allergies are called Th2 disease. The chemicals emitted are called interleukins,which activate the IgE production of previously discussed B-cells and the recruitment of mast cells. Then the antibodies are attached to mast cells and basophil granulocytes. Both types of cells belong to the group of white blood cells and are responsible for inflammatory immune reactions. So when these white blood cells with IgE antibodies are linked to molecules classified as allergens, they cause them to release chemicals that are responsible for the symptoms.
This process is called sensitization and this is the first step in the development of allergies.
The next phase is the symptomatic phase. All allergic reactions are based on cross bonding, which means that the allergen binds on two IgE antibodies at the same time, yet the symptoms can appear on different organs, such as the skin, stomach, eyes...
Allergens are usually proteins that can trigger the interleukin production of Th2 cells in small quantities. At present, they have not yet been able to determine the protein structure that would clearly be characteristic of allergens, it is certain that the antigen is recognized by the antibody through so-called epitopes, which is a recognizable sequence of 6-15 amino acids.
Cross-reaction allergens
Cross-reaction is an antibody which can bind to the epitopes of two different antigens. In its presence, these proteins come from the same family and may not cause allergic symptoms individually, but together they do. For example, birch flakes and fruits quite often contain cross-reactive allergens. Often,if we change the 3D structure of the protein, for example, by heat treatment, we can reduce the cross-reaction.
Food allergy
Cases of food allergies have increased in recent years, mainly due to environmental factors such as vitamin D deficiency, reduced consumption of Omega 3 fatty acids and antioxidants, or obesity. They regularly try to develop tactics to prevent allergies, in one of the studies they write about how during pregnancy and babies should not be given food prone to the development of any allergies. In the next study, it is already written that if we start eating peanuts at a young age, we are less likely to become allergic to it. Unfortunately, no one can give clear advice on how we can safely avoid food allergies, but what is certain is that a balanced healthy diet will improve our children's and our own chances.
During the food allergy we organized a protein present in the food reacts with allergic symptoms.
Milk protein allergy
Cow's milk protein allergy is one of the most common allergies in the whole world, contains more than 20 types of protein and is all potential allergens. It occurs mainly in infants, but it can affect our whole life and the symptoms can vary from person to person. The two most common allergens are casein fractions and beta-lactoglobulin. Human milk is beta-lactoglobulin-free,inaddition, camel milk is like this, other mammals whose milk is commonly consumed - lactoglobulin is the main whey protein. Casein also varies from species to species, including the composition of the amino acid and the map of the peptide.
In cow's milk, casein can be fractionated into alpha, beta, kappacasein, and whey protein is made up of alpha-lactalbumin (alpha-la), beta-lactoglobulin (beta-lg), bovine serum albumin (BSA) and immunoglobulin (Igs).
Since proteins can be denatured under the influence of heat, the question arises whether we can reduce the allergen content of milk. Unfortunately, caseins are very thermostable proteins, so if you have a problem with casein, this is not the solution and beta-lactoglobulin has similar properties, but it decomposees well BSA and Igs at 70-80 °C, so these two proteins can lose their allergenic properties by heat treatment. When making cheese, most whey proteins are lost and degraded, so if you are allergic to them, you may want to try harder aged cheeses.
Lactose sensitivity
Lactose is the main carbohydrate in human milk as well. Lactose is digested by enzymatic hydrolysis, which means that lactose is converted into D-galactose and D-glucose with the enzyme lactase by the addition of water. In infancy, the body produces the enzyme lactase, which is fine, but those who still retain the activity of the enzyme lactase are due to the mutation that has developed over many centuries. Currently, 70% of the world's population loses the ability to produce the enzyme lactase by adulthood.
Fortunately, it is no longer complicated to produce a lactose-free product at all, under the right conditions they can pre-digest 80% of lactose with the enzyme lactase in about 3 hours so that our body no longer has to bother with this. In ripened dairy products, the lactose content is reduced to zero in about 10 days. Enzymes convert lactic sugar into lactic acid.
I would like to point out in particular that lactose sensitivity is not the same as milk protein allergies! During lactose sensitivity, we have a digestive problem and only our digestive system participates in it, while during milk protein allergy, our body's immune system is involved in the disease.
Histamine sensitivity
Histamine is a biogenic amine that plays an important role primarily in our immune system, produced by basophilic and mast cells. When our body reacts to an infection or disease with inflammation, it is also due to histamine, in addition, it expands the tiny small passages through the vascular wall so that the cells of our immune system can more easily arrive at the site of the attack. Even during our allergic reactions, when the allergen binds to the mast cell, they also excrete histamine, so these amins also play an important role in the allergy process. Histamine is found in almost all tissues of our organism. It can be released from these immune cells under the influence of countless factors, such as extremely high temperatures, trauma, alcohol, certain foods and medications. These were the cases where our body produces histamine itself, but there are countless cases where we introduce this histamine into our body with different foods and microbes. Histamine can be formed from a protein by decarboxylation, which means that a group of carboxyls of a molecule is detached and carbon dioxide is formed. But that's not what's interesting, it's that many bacteria are capable of this process, and quite a few of them are members of the human microbiome, that is, they are part of the healthy intestinal flora. These microbes are also often used for fermentation, so histamine is also found in most fermented foods, most of which are lactic acid bacteria. Some bacteria can even decarboxylicate at +4°C, so if you want to avoid the histamine you should to store your food frozen. Some dishes naturally contain large amounts of histamine, such as spinach, tomatoes, etc...
In order to get rid of excess histamine that has entered the body, our organism produces enzymes. Two, diaminooxidase and N-methyltransferase, depending on which part of our body is activated, which part of our body has a histamine surplus. Histamine intolerance (HIT) occurs when the production of an enzyme in our body ceases. To treat this, it is recommended to maintain a histamine-free diet for a month, avoid histamine as much as possible, and then slowly try to get your body back on a food-by-food basis.
So in this case, we're not sensitive to histamine, we're just incapable of breaking it down when we don't need it. It is often confused with a normal allergy, even though this disease is one of intolerances.
Resources:
M. Hennebelle, H.F.J. Savelkoul, P.L. Weegels, H.J. Wichers, Reader of Food related allergies and intolerances, Wageningen university and researches
https://edepot.wur.nl/198202#page=70
https://www.sciencedirect.com/science/article/abs/pii/S0921448806002574
https://link.springer.com/article/10.1186/s40413-017-0173-0
https://www.sciencedirect.com/science/article/pii/S002203028580789X
http://acta.bibl.u-szeged.hu/21129/1/szef_tudkozl_017_109-120.pdf
https://www.sciencedirect.com/science/article/abs/pii/S0301054615000932