Study: Skin infections increase the risk of allergic asthma!

Study: Skin infections increase the risk of allergic asthma!

A recent study by the Medical University of Vienna and the CeMM Research Center for Molecular Medicine shows alarming results regarding the effects of skin infections on the immune system. The research, published in the renowned journal Science Immunology, examines the consequences of local infection with Staphylococcus aureus (S. aureus) and its long-term influence on the immune response in mice. S. aureus can act as both harmless and pathogenic and plays a significant role in the development of skin infections.

After an infection with S. aureus, not only neutrophil granulocytes but also eosinophils migrate to the inflamed region. Eosinophils are a type of white blood cell that is particularly important in allergic diseases. The research shows that such a skin infection leads to permanent changes in the bone marrow, where eosinophils are produced. These eosinophils, isolated from infected mice, exhibit a pro-inflammatory signature that persists even after the infection resolves.

Long-term consequences and allergies

The infected mice developed increased allergy-induced inflammation in the lungs after coming into contact with house dust mite allergens. In addition to an increased number of eosinophils in the lung tissue, these animals also showed a significantly increased production of allergy-promoting antibodies and impaired lung function. It turned out that the increased immune reaction is mediated by the eosinophils from the altered bone marrow.

Most notably, transplantation of eosinophils from infected mice to healthy mice resulted in increased allergic inflammation. The influence of two messenger substances, interleukin-33 (IL-33) and C5a, also proves to be crucial for these immune changes. IL-33 promotes the proliferation of eosinophils in the bone marrow, while C5a is responsible for directing the changes in immune cells to the lungs. According to the study authors, targeted blocking of these signaling pathways could represent a promising treatment strategy for allergic diseases such as asthma.

Additional insights into asthma and allergies

The research is consistent with previous studies looking at the role of eosinophils and basophils in asthmatic reactions. Studies have shown that basophils are less prominent in the bronchi of asthmatics than eosinophils and mast cells, which occur in significantly higher levels. By comparing bronchial biopsies from atopic and non-atopic subjects, it was found that basophils gain weight but still make up less than 10% of eosinophils.

These immune responses are crucial because they represent the body's defense mechanisms against infections. The adaptive immune response can be triggered by environmental antigens such as pollen or food and lead to allergic reactions. Over the last two decades, allergic diseases have increased, particularly in the Western world. The influence of environmental factors and genetic predispositions plays an important role.

In summary, current research results indicate that bacterial skin infections not only cause acute reactions, but can also cause long-term changes in the immune system that contribute to the development of allergies and asthma. This highlights the need for further studies to develop possible therapeutic approaches and to deepen the understanding of the connections between skin infections and allergic reactions.

For more information, read the full study OTS, PubMed and PMC.