RT Journal Article SR Electronic T1 Variable Clinical Phenotypes and Relation of Interferon Signature with Disease Activity in ADA2 Deficiency JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 523 OP 526 DO 10.3899/jrheum.180045 VO 46 IS 5 A1 Insalaco, Antonella A1 Moneta, Gian Marco A1 Pardeo, Manuela A1 Caiello, Ivan A1 Messia, Virginia A1 Bracaglia, Claudia A1 Passarelli, Chiara A1 De Benedetti, Fabrizio YR 2019 UL http://www.jrheum.org/content/46/5/523.abstract AB Objective. An upregulation of type I interferon (IFN) stimulated genes [IFN score (IS)] was described in patients with adenosine deaminase 2 deficiency (DADA2). We describe the clinical course of 5 such patients and the role of IS as a marker of disease activity and severity.Methods. Expression levels of IS were determined by quantitative real-time PCR.Results. Five white patients were identified as carrying CECR1 mutations. The IS before treatment was elevated in 4 out of 5 patients and decreased after treatment.Conclusion. Our data confirm the high variability of DADA2 and suggest type I IS as a biomarker of disease activity.