Association of IgG4-related disease and sarcoidosis.

findings of this study are (i) PTR-MS evidence for the flow dependency of exhaled acetone; (ii) changing minute ventilation can both increase and decrease the concentrations of selected exhaled trace gases; and (iii) concentrations of certain volatiles were not significantly altered by respiratory manoeuvres in healthy volunteers. These preliminary observations may have important implications regarding the standardisation requirement for measuring and reporting the concentrations of exhaled trace gases in the future. Further larger studies both in healthy and diseased subjects are necessary to expand on these observations and to provide mechanistic insights into exchange kinetics of affected volatiles. Such studies may help to further define the exact role of on-line MS technologies in non-invasive diagnosis and monitoring pulmonary and systemic diseases.