Today, allergies are quite common diseases and are fully accepted in terms of the mechanism by which they occur and the symptoms they can present. There are numerous diagnostic tests that are adjusted to each type of allergy and the allergens that cause them and we also have a wide range of treatments, in addition to the continuous advances in the cure: immunotherapy. However, the study of allergies as a disease with unique characteristics appeared at the beginning of the 20th century.
A disease of the immune system
In this article we will review what was known at that time about diseases of the immune system and the increasingly frequent appearance of a type of reaction that no one fully understood.
The field of immunology had great advances at the end of the 19th century. The investigation of pathogens and the development of vaccines marked a before and after in the way of understanding the relationship of our organism with foreign elements. Many research centers were founded in Europe where pathogens and some elements of the immune system were discovered, such as antibodies or different cell types involved in infections and tolerance to these pathogens.
On the other hand, during the period of industrialization, the use of vaccines and the improvement in hygienic measures in a large part of society, strange reactions and diseases that had not been seen before began to appear. Although some doctors suspected that they could be caused by the immune system itself, there was no clear evidence. It was not until 1903 that a Viennese pediatrician became interested in this type of reaction and began to lay the foundations for the study of allergic reactions. This pediatrician, Clemens von Pirquet, studied medicine, among other things, and began practicing at the Kinderklinik (Pediatric Hospital) in Vienna in 1900. His work, closer to the patient’s bedside than to the laboratory bench, led him to be interested in those reactions that had no explanation.
Since when are allergies studied?
In 1903 von Pirquet published a first report entitled Zur Theorie der Infektionskrankheiten (On the theory of infectious diseases). In this report he advanced the idea that the response of the immune system in the form of infections was the combined result of an innate and adaptive response. What differences are there between these answers and why was it so important?
The studies published in previous years in the field of immunology focused on a type of immune response that we know as the innate response and that is the result of an evolution in the presence of viruses or bacteria that pose a danger to our health. This response was believed to be activated when a microorganism entered our body and began to invade our cells with harmful compounds such as toxins. This type of response is present in all people, regardless of whether they have been in contact with those pathogens or not; we have it “as standard” and that is why it is called an innate response.
On the other hand, we have the adaptive response, which is acquired throughout the life of each person. This type of response is triggered by first coming into contact with certain foreign molecules and serves as protection for future encounters. As it requires an “adaptation” of our immune system to the environment, it is called an adaptive response.
We now know that allergies are included within the type of adaptive responses, which are acquired throughout the life of each person based on environmental factors and/or genetic predispositions. Clemens von Pirquet was the one who coined the term “allergy” in 1905, combining the words allos (other) and ergon (work) from the Greek to describe a hypersensitive reaction to something foreign.
But what led von Pirquet to think that allergies were adaptive responses? His main argument was that this type of reaction in different experimental models, clinical observations and studies on vaccination and tolerance, needed a specific time until the body activated the response. The Viennese pediatrician deduced that this time was necessary to create the antibodies responsible for the reaction, and therefore, an adaptation was carried out; adaptive response.
In the following years, von Pirquet published several articles together with his collaborators that pointed out that his argument was true, as well as other parallel publications on anaphylaxis reactions by other researchers that he took as inspiration. The contribution of this Viennese pediatrician is still palpable in the allergy research centers in Vienna, and not only because of the bust in front of the entrance to the Kinderklinik. However, in that golden age of immunology, accusing the immune system of dangerous reactions against the body itself was too transgressive. Although he was not recognized by the scientific community and was mocked for several years, today we continue to appreciate his contribution and allergies are more than accepted in medicine.
References:
Von Pirquet et al. 1903. Zur theorie der inkubationszeit. Wien Klin Wochenschr. 1903;16, 1244-1247.Igea. 2013. The history of the idea of allergies. allergies. doi: 10.1111/all.12174Von Pirquet et al. 1905. Die Serumkrankheit. Deuticke, Wien.
