Scientists from St Petersburg University have suspected autoantibodies of involvement in heart diseases, which are not yet considered autoimmune

The participants of the 4th International Academy of Autoimmunity, which will be held at St Petersburg University on 11–13 October, will talk about what other relevant research is being conducted nowadays in this area.

Autoantibodies are immunoglobulins that target the cells of a person’s own body. Paul Ehrlich, a German scientist, was at the forefront of immunology. He believed that autoantibodies are always pathogenic, and autoimmunity is a phenomenon that cannot be physiological. Another point of view was held by Élie Metchnikoff, a famous Russian scientist and associate professor of St Petersburg Imperial University. He said that autoimmunity, on the contrary, is a physiological phenomenon, but only when it is moderate and properly regulated. At present, more and more studies are appearing that autoantibodies are present in small quantities in the blood of healthy people. It turns out that they play a regulatory role – similar to the action of hormones or neurotransmitters.

In a review article published in a peer-reviewed journal Autoimmunity Reviews, researchers from St Petersburg University and the University of Bari (Italy) put forward their own classification of autoantibodies. It consists of two large groups – cytotoxic autoantibodies (damaging to cells) and regulatory ones (acting through their target molecules on the functions and growth of various cells of the body). In total, the review included about 150 academic papers informing about which autoantibodies are common in the blood in people with various cardiovascular diseases.

‘On the one hand, these scientific papers showed that the blood in people with heart diseases indeed contains more autoantibodies than that in healthy people,’ said Varvara Ryabkova. She is the first author of the review, a young scientist, a laboratory assistant and researcher at the Laboratory of the Mosaics of Autoimmunity, St Petersburg University. ‘On the other hand, fundamental studies found that these antibodies can have a direct effect on heart cells. They change such properties of the heart muscle as excitability, capacity, contractility, and heart rate. This means that they can potentially be triggering factors for the development of arrhythmias.’ 

The Laboratory of the Mosaics of Autoimmunity at St Petersburg University was opened in 2017 under the mega grant programme of the Government of the Russian Federation for state support of scientific research. It is headed by Yehuda Schoenfeld, a member of the Israel Academy of Sciences and Humanities, PhD in Medicine, professor, founder and head of the P. Zabludovich Autoimmune Disease Center at the largest hospital in Israel - H. Sheba Medical Center at the University of Tel Aviv, president of international autoimmunity congresses, as well as one of the world leaders in the study, treatment and prevention of autoimmune diseases.

The researchers managed to find out that the cardiovascular complications that sometimes occur after vaccination against the human papillomavirus infection (HPV) may have an autoimmune development mechanism. The fact is that there is an antigenic community between HPV and the proteins that are contained in cardiac myocytes (muscle cells of the heart). Their structures are similar, therefore antibodies against HPV can cross react with proteins of cardiac myocytes, i.e. they can affect not only the virus, but also heart tissue. However, as the co-author of the study emphasises, this is not a cause and effect relation, but a fact that requires further study.

Additionally, autoantibodies can play an important role in sudden cardiac death syndrome, when death occurs suddenly – within an hour – from acute heart failure, although before that a person might not have had any cardiovascular disorders. Unfortunately, young people, including adolescents, are also prone to sudden cardiac death syndrome. In 30% of cases, even after posthumous post-mortem, histological and genetic research, doctors cannot find out the true cause of death. It is in these cases that autoantibodies might play an important role.

‘If we find out “death antibodies”, we might create “antibodies of life” or prevent such cases of sudden death,’ said Leonid Churilov, Deputy Head of the Laboratory of the Mosaics of Autoimmunity, Head of the Department of Pathology, St Petersburg University.

In the future, scientists from the Laboratory of the Mosaics of Autoimmunity want to see during the experiments how autoantibodies that appear in various conditions affect the cardiovascular system of laboratory animals. Additionally, they will continue to study the effect of autoimmune mechanisms on the course of other diseases that affect the blood circulation. An example is chronic fatigue syndrome and postural tachycardia syndrome, in which, during a sharp rise, the heartbeat of a person increases rapidly.

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autoimmune diseases are known to science today. The most common of them are: allergic thyroiditis; insulin dependent diabetes mellitus; multiple sclerosis; psoriasis; lupus erythematosus; rheumatoid arthritis; ulcerative colitis; and coeliac disease.

Moreover, every tenth inhabitant of the planet suffers from at least one of the autoimmune diseases. The fact that modern science knows about the causes, mechanisms, diagnosis, prevention and treatment of autoimmune diseases will be described by the participants of the 4th International Academy of Autoimmunity. It will be held at St Petersburg University on 11–13 October. To find out more about the event, visit the event website.