Clinical Impact of Fungal Domestic Environmental Exposure on COPD Patients

Overview

Fungal infections could play a role in chronic obstructive pulmonary disease (COPD) patient's exacerbations and in lung function impairment. In fact, Aspergillus fumigatus is often isolated from respiratory samples, but few data are available about its clinical significance. Aspergillus colonization could be associated to a higher risk of invasive pulmonary aspergillosis (IPA), which, in COPD patients, is characterized by a 2% incidence (probably underestimated) and a high mortality (72 to 95%). Similarly, detection of anti-Aspergillus antibodies is quite frequent in COPD patients but its significance and usefulness for aspergillosis diagnosis and follow-up have not been assessed. Furthermore, several studies suggest a frequent carriage of Pneumocystis jirovecii, reaching 37-55%, with a higher frequency in the most severe COPD stages and a possible role of colonisation in the occurrence and progression of COPD. As these colonization and sensitization phenomena could be related to domestic exposure to airborne or, for P. jirovecii, to human reservoirs, the investigators set-up a study in order to (i) Evaluate how domestic exposure to mould or to P. jirovecii could impact fungal colonization and sensitization frequency in COPD patients, (ii) Study the relationship between these fungal colonization/sensitization phenomena and lung function impairment in the course of COPD and (iii) Have a better understanding of mould and P. jirovecii circulation in the close environment of patients (between airborne, human reservoirs and patients). In fine, this study will provide data (i) On fungal contamination levels (species and conidia concentration) of COPD patient's homes in a French region, (ii) On the relationship between fungal exposure level and colonization/sensitization phenomena, (iii) On the role of fungal colonization/sensitization in lung function impairment, (iv) To design diagnostic, therapeutic, and preventive options for the management of COPD patients, taking into account fungal environmental exposure and colonization/sensitization impact on the evolution of the disease.

The investigators will focus on both the patient and its domestic environment. More precisely, for 80 patients, the investigators will measure mould domestic exposure (determination of mould frequency during an environmental investigation at the patient's home), search for mould sensitization and colonization (complete bio clinical check-up including spirometry, inflammatory and mycological markers at inclusion), and do a clinical follow-up of exacerbation's (frequency and severity). At last, clinical and environmental mould and P. jirovecii isolates will be characterized at the phenotypic and genotypic level.