Corticosteroids/β2-agonists in Hair in Asthmatic Patients (CorticHair)

Asthma affects 3-10% of the European population and is a heterogeneous disease in its clinical manifestations and also in its response to treatment. Since therapy is often started at young age and given over many years, with adjustments made on disease control, long-term adherence and efficacy are particular concerns. Adherence to inhaled controller medications is a major challenge to obtain disease control and to avoid serious asthma flare-ups or unnecessary treatment stepping up. In addition to adherence concerns, poor asthma control may also be the consequence of a poor inhalation technique and the resulting insufficient drug exposure. To overcome adherence issues, patients are encouraged to self-manage their disease and the use of new technologies such as inhaler reminders, electronic devices and/or smartphone applications may be helpful. Although there is a margin to improve and monitor adherence, assessing the efficiency of the inhalation technique in daily routine and its consequences in terms of drug exposure is much harder. The traditional monitoring of pharmacological therapies involves therapeutic drug monitoring, i.e. the measure of drug concentration in plasma. But drugs concentration in plasma most only reflect the quantity of drug in the body in the last 24-48 hrs only. Hence, therapeutic drug monitoring is not used for inhaled asthma treatments, in part because of the limited interest in assessing only a 24-48 hrs exposure and of the very low plasma concentrations which are very challenging to measure. Since drugs present in the bloodstream also reach and stay in the forming hair where their concentrations can be measured and interpreted as an overall chronic exposure, hair analysis could become a valuable tool in the monitoring of inhaled asthma treatments, with the use of very specific mass spectrometry techniques and of the most sensitive last-generation mass spectrometers.