The Minasarc study: A case-control study measuring mineral exposome in sarcoidosis

International audienceIntroduction: it has been suggested that sarcoidosis could be associated with exposure to inorganic particles (Newman LS Curr Opin All Clin Immunol 2012; 12:145-50, Vincent M et al Am J Ind Med 2015; 58:S31-8).Objectives: in order to test this hypothesis the Minasarc study was designed to evaluate the mineral exposome by a specific questionnaire (SQ) and a mineralogical analysis performed on BALs by optical and electron microscopy in patients and healthy volunteers (HV). We present here the results obtained by the SQ which can be considered as a tool for global assessment of the “whole life” exposure to inorganic particles in occupational and environmental contexts.Methods: The study was performed on 20 patients with sarcoidosis and 20 HV. Every HV was matched to a patient by sex, age and smoking habit. The SQ was calibrated with a representative sample of the French population (n=825) in the ELIPSSilice survey (ANR-10-Eqpx-19-01) and the result was expressed as a “dust score”. Scores were compared by a Wilcoxon signed-rank test.Results: The “dust score” was found significantly higher in patients with sarcoidosis than in HV (p=0,036; Wilcoxon signed-rank test). Moreover we found a significant overrepresentation of people exposed to building activities among the cases. However this remains to be assessed on a larger series.Conclusion: The SQ demonstrated a significantly higher level of exposure to inorganic dusts in patients with sarcoidosis compared to HV. Such preliminary results encourage 1) to study the association between sarcoidosis and inorganic dust exposure and 2) to submit routinely this exposure questionnaire to every patient with a granulomatous disease