Inorganic exposome in pediatric sarcoidosis: The PEDIASARC study

Background: Sarcoidosis in children is a rare, often multiorganic and severe disease. It is believed to appear in genetically predisposed individuals, exposed to environmental triggers. We aimed to study inorganic exposome in pediatric sarcoidosis. Methods: With the French network for Rare Lung Diseases (RespiRare), we collected information on pediatric lung sarcoidosis. The patient and his parents were asked to answer a questionnaire adapted from the adult MINASARC case-control study. In case of possible current exposure, or in the absence of move since the onset of the disease, a mineralogical analysis of the indoor air and the biopsies will be proposed. Results: So far, 20 patients (median age 10), mostly from Afro-Caribbean and Subsaharian origin, are included. The questionnaire revealed that the parents of 13 patients had at least one occupational exposure (cleaning, packaging and shipment in warehouses, building, cardboard manufacturing, metalwork, waste sorting, mechanic, cabling installation in confined areas). A non-occupational exposure was also reported in 13 patients: pottery, geophagy, scouring powder inhalation, blowing talc gloves, cat litter exposure, coal handling, living close to a construction site. Discussion: The study sheds light on a possible high risk of abnormal inorganic exposure in pediatric patients with sarcoidosis. These results argue for an environmental participation in the disease onset and/or progression. Correlations between exposure and inorganic particles in the indoor air and on biopsies will further be studied. This study helps consider afresh the so-called “genetic” and “environmental” factors by highlighting some environmental specificities of migrants9 living conditions.