Assessment of type I interferon response in routine practice in France in 2022

Abstract

An European Alliance of Associations for Rheumatology task force recently recommended specific points to consider for exploring type I interferon pathway in patients, highlighting the lack of analytical assays validated for clinical routine. We report here the French experience on a type I interferon pathway assay that has been set up and used routinely since 2018 in Lyon, France.

Keywords: Autoimmune Diseases; Cytokines; Dermatomyositis; Lupus Erythematosus, Systemic.

Figure 1

(A) Geographical distribution of ISG expression score prescriptions in France in 2022. (B) Demographic features of patients for whom we performed an ISG expression score. (C) ISG expression score according to the indication for which the ISG expression score has been performed. Red line: median ISG expression score for each indication. Black dot line: positive threshold (2.3). (D) Overview of the prescribers of ISG expression score in 2022. (E) Reproducibility of our type I interferon pathway assay. Reproducibility Coefficient of Variation (CV) calculated from repeated measurement of the same IQC over time (two different IQC used, IQC#1 and IQC#2). (F) Repeatability of our type I interferon pathway assay. arb. unit: arbitrary unit. CAPS, cryopyrin-associated periodic syndrome; CTD, connective tissue disease; DM, dermatomyositis; FMF, familial Mediterranean fever; ICU, intensive care unit; IFN, interferon; IQC, internal quality control; JIA, juvenile idiopathic arthritis; PFAPA, periodic fever with aphthosis, pharyngitis and adenitis; PID, primary immunodeficiency; PIMS, paediatric inflammatory multisystem syndrome; RF, recurrent fever; SLE, systemic lupus erythematosus.