Scientists from the Helmholtz Zentrum München now have shown that many of the adult patients with CF in addition lack a cell surface molecule, which is important for immune defence. The results have been published recently in the Journal of Molecular Medicine.

Cystic fibrosis (mucoviscidosis) is due to a mutation of an ion channel which leads to highly viscous mucus and to dysfunction of the lung and the gastrointestinal organs. Since these patients frequently suffer from chronic infections, Dr. Thomas Hofer and Professor Dr. Loems Ziegler-Heitbrock from the Comprehensive Pneumology Center (CPC) at Helmholtz Zentrum München — together with colleagues at the Klinikum der Universität München and the University of Leicester, UK — investigated, whether these patients might have an additional immune defect. The scientists found that the immunological cell surface molecule HLA-DQ is reduced or absent in many of these patients.

Defect is seen in all relevant leukocyte populations

HLA-DQ belongs to the MHC class II molecules, which can present crucial parts of invading microbes to immune cells such that the latter are activated leading to specific elimination of the pathogens. The class II molecules are strongly expressed on primary immune cells such as monocytes, macrophages and so-called dendritic cells. The study showed that HLA-DQ is reduced or absent in all these cell types in the blood and in the lung. Hence, all of the relevant antigen-presenting cells of the immune system are affected.