DZL scientists discovered altered numbers of B cells in the blood of asthmatics. The results from the ALLIANCE registry could help detect inflammation in the small airways more easily in the future.
B cells are an important component of the human immune system. Ideally, they recognize invading pathogens and produce specific antibodies to fight them. The fact that an asthmatic disease affects the B cell repertoire was already known from preliminary studies in animal models. Researchers of the ALLIANCE registry now investigated patients with asthma using clinical data and blood samples from more than 180 patients and healthy controls.
The scientists from the DZL sites ARCN, BREATH and CPC-M discovered that particularly in severe asthma, fewer immature B cells circulate in the blood of patients compared to healthy individuals. Immature B cells are immune cells that have not yet had contact with a pathogen. With their specific receptors, they can bind pathogens, so-called antigens, leading to b cell-activation. This activation is also known as the maturation process, which ensures the formation of memory B cells and the production of antibodies. The antibodies produced by the B cells bind the pathogens and trigger an elimination process.
Improving the diagnosis of inflammation of the small airways
The researchers found a specialized form of B cells, so-called IgA-positive memory B cells, to be particularly common in those patients who had deteriorated lung function and damage to the small airways. IgA (immunoglobulin A) is a class of antibodies that plays a particular role in the defense against pathogens that enter through the mucous membranes. There were also more IgA-positive memory B cells in patients with frequent acute episodes of disease (exacerbations). The results now offer the opportunity to better diagnose inflammation of the small airways in the future. Up to now, there have been few other possibilities in this area of the lung, as sampling in the finely branched airways is generally impossible. However, the biological significance of the association found between IgA-positive memory B cells and small airways remains to be explored. Nevertheless, it may be possible to develop an asthma therapy that takes advantage of this connection.
Habener A, Grychtol R, Gaedcke S, DeLuca D, Dittrich AM, Happle C, Abdo M, Watz H, Pedersen F, König IR, Thiele D, Kopp MV, von Mutius E, Bahmer T, Rabe KF, Meyer-Bahlburg A, Hansen G (2022) IgA(+) memory B cells are significantly increased in patients with asthma and small airways dysfunction. Eur Respir J (ARCN, Assoziierter Partner, BREATH, CPC-M) https://doi.org/10.1183/13993003.02130-2021
Habener A, Happle C, Grychtol R, Skuljec J, Busse M, Dalüge K, Obernolte H, Sewald K, Braun A, Meyer-Bahlburg A, Hansen G. Regulatory B cells control airway hyperreactivity and lung remodeling in a murine asthma model. J Allergy Clin Immunol. 2021 Jun;147(6):2281-2294.e7. doi: 10.1016/j.jaci.2020.09.041. Epub 2020 Nov 27. PMID: 33249168.