Exhaled Breath Analysis by Secondary Electrospray Ionization - Mass Spectrometry in Children and Adolescents

Participants will be asked to refrain from eating, drinking, chewing gum use or brushing their teeth at least 1 hour before the measurements will be performed. Room temperature and lighting will be set at the same level for all measurements. Participants will exhale through a disposable mouthpiece into a commercially available SESI source (FIT S.L., Spain). While performing full exhalations, the subjects will keep the pressure through the sampling line at a fixed value monitored by a digital manometer. Breath prints will be collected in real-time recording multiple replicates (typically six in positive and negative ion mode). The whole procedure is absolutely non-invasive and is usually accomplished without any effort in around 15 min per subject.

In young children below the age of 4 not capable of completing the on-line exhalation maneuvers, or in cases when the patient needs cannot approach the mass spectrometer, the sample will be collected off-line. They will be asked to exhale into a bag that will be transported to the lab and deflated into the mass spectrometer for analysis. Exhaled breath of patients under anesthesia will also collected using available ventilation system in the operation theatre.

Blood analysis done in patients who undergo regular blood sampling needed for clinical routine laboratory controls. This includes i) children and adolescents receiving medications which require TDM ii) patients with acute diseases such as TD1 and pneumonia and iii) patients with chronic diseases such as asthma bronchiale. For those patients where a blood sample is drawn during the clinical routine, an additional blood sample consisting of only several blood drops will be collected using the same blood sampling line. No additional venous puncture for research purpose will be done.

During the diagnostic and therapeutic work-up of T1D patients, saliva samples are collected during the clinical routine. For those patients, additional samples will be obtained by clinically trained investigators.

During the diagnostic and therapeutic work-up of T1D patients, urine samples are collected during the clinical routine. For those patients, additional samples will be obtained by clinically trained investigators.