Clinical and Genetic Study of Familial Sarcoidosis (SARCFAM)

Overview

Major impacts of air pollution are lung diseases such as granulomatous diseases and mainly sarcoidosis. Understanding the respective role of inorganic / nanoparticles and genetic background in these chronic diseases is a major challenge for the management of patients and prevention strategies. Granulomas are characterized by giant epithelioid and multinucleated cells, reflecting a severe disturbance in immunological pathways induced both by toxic exposure and genetic predisposition. Previous studies demonstrated that professional environmental context and acute exposures (the World Trade Center disaster) to micro/nanoparticles have a pathogenic impact with a sharp increase in sarcoidosis. Sarcoidosis is a multifactorial disease occurring in a genetically vulnerable context. Many gene variants have been linked to an increased odds-ratio of the disease, such BTNL2, CCDC88B, ANNEXIN A11 involved in regulation of T-cell activation and maturation pathways. We have contributed since 2008 to a national cohort (GSF, 28 centers) of ≈ 800 sarcoidosis patients with familial and sporadic presentation of the disease. This collection has been an exceptional (and worldwide unique) tool for the implementation of an exhaustive clinical database on sarcoidosis, modelling of disease evolution and identification of clinical / genetic criteria differentiating sporadic and familial forms. The main goals of the project are: 1. Completion of the genetic data in order to establish a pattern of gene variants segregating with familial forms of the disease, compared to sporadic one. This will be done by WES (WHOLE EXOME) analysis on the previously collected DNA samples. The informed consent for the patients included the information about the BTNL2 gene, which has been already tested since 2008, and related genes connected to immune pathways, thus allowing a unambiguous information about the research finality of the project. 2. Completion of the clinical data about each patient, in cooperation with the GSF network, management of the database established since 2008. The data collected are those which are commonly detailed in the normal follow-up of the patients. The project do not include any new interventions on the patient (neither radiological or invasive tests). 3. Specific biological studies might be done on the white blood cells of the patients, and might need in such cases a new blood sampling, both in patients and first degree related healthy controls. Theses specific studies will be presented to an ethical committee (CCP) in order to validate the feasibility in term of 'new intervention' on the cohort. The samples collected will be at the same volume of a classical blood sampling (2\*7 ml). 4. Any other projects, submitted to the GSF network will needed a specific registration and ethical committee validation.