Despite ongoing development of existing treatment principles as well as new treatments there are currently patients who develop such severe asthma that they are not helped by the drugs they receive – so called uncontrolled asthma. Researchers across the world therefore continue to study the underlying disease mechanisms.
Prof. Anders Lindén's research team at Karolinska Institutet, in collaboration with Prof. Leif Bjermer's research team at Lund University, has examined the presence of the cytokine interleukin(IL)-26 in adult patients with asthma. The work is a continuation of previous studies into IL-26, where Anders Lindén’s research group has among other things been able to demonstrate higher levels of local IL-26 in the airways in certain children with uncontrolled asthma.
The current results show similarities between adults and children, i.e. on average there are substantially higher levels of local IL-26 in airways in the group of subjects with uncontrolled asthma compared to subjects with controlled asthma. This finding is clear even though both patient groups are being treated with anti-inflammatory drugs and bronchodilators according to the most recent international guidelines.
"At the same time, we are showing that all patients with asthma, regardless of the severity of the disease, have an on average lower local level of IL-26 than healthy subjects do. We think that this latter finding is very interesting since we have found in a previous study that IL-26 contributes to the mobilization of important anti-bacterial cells, so called neutrophils, during an infection. It is a long-known fact that all patients with asthma have an increased vulnerability to bacterial infections", Lindén explains.
In the patient group with uncontrolled asthma, the researchers also noted that the patients with the poorest disease control were characterized by a low local level of IL-26, something that the researchers believe might indicate that IL-26 has a protective effect and that these patients lack the ability to react with adequate production of IL-26. In the group of patients with asthma as a whole, the researchers found a negative correlation between a local level of IL-26 and lung function and the presence of inflammatory cells other than neutrophils.
"In light of existing experimental litterature, these findings could be interpreted as a general increase of local IL-26 as a consequence of severe asthma and that it in fact has a protective effect against inflammation. The generally lower level compared to healthy persons could then be due to the long-term cortisone treatment that the majority of patients with asthma receive. All in all, our new research results indicate that IL-26 might be a useful biomarker for uncontrolled asthma in adults as well as children, something that could benefit future medical care," says Lindén.
MEDICA-tradefair.com; Source: The Swedish Research Council