IL-17 in human asthma.

Asthma is perceived as a heterogeneous disease with several clinical phenotypes and triggering factors. In general, cytokines from T-helper 2 cells are believed to be critical contributors of asthma. In recent years, IL-17, another T-helper lymphocyte-associated cytokine, has been put forward as another potentially important mediator of asthma. Currently, several drugs that target IL-17 signaling are being tested in clinical trials. With the aim to find whether there are any specific features of this heterogeneous disease that potentially could be relieved by the use of IL-17-targeting drugs, this review scrutinizes the evidence for an involvement of IL-17 in human asthma.