title: Longitudinal expression of type I interferon responsive genes in systemic lupus erythematosus.
abstract: Cross-sectional studies of patients with systemic lupus erythematosus (SLE) have demonstrated an association between activation of type I interferon (IFN) pathway and disease activity. This study examined longitudinal changes in IFN-regulated gene expression in peripheral blood using microarrays. A cross-section of 66 patients from the Autoimmune Biomarkers Collaborative Network SLE archive was evaluated. We also examined paired samples from a 15 patient subset collected during a period of low disease activity (Baseline) and at a subsequent flare event, and baseline scores of 29 patients who maintained low disease activity. IFN response (IFNr) scores were calculated from three IFN-regulated genes. Overall, higher IFNr scores were associated with increased disease activity. However, IFNr scores were not significantly different between the paired Baseline and Flare samples. An extended longitudinal analysis in 11 patients indicated little change in IFNr scores over time, even during dynamic disease activity. In patients with low disease activity, IFNr scores were not different between patients who experienced a subsequent flare and those who maintained low disease activity. In summary, although higher IFNr scores were associated with greater disease activity, IFNr scores of individual patients did not correlate with changes in disease severity or flare risk.
authors.affiliation: Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA. mpetri@jhmi.edu
authors.forename: M
authors.initials: M
authors.lastname: Petri
authors.forename: S
authors.initials: S
authors.lastname: Singh
authors.forename: H
authors.initials: H
authors.lastname: Tesfasyone
authors.forename: R
authors.initials: R
authors.lastname: Dedrick
authors.forename: K
authors.initials: K
authors.lastname: Fry
authors.forename: Pg
authors.initials: P
authors.lastname: Lal
authors.forename: G
authors.initials: G
authors.lastname: Williams
authors.forename: Jw
authors.initials: J
authors.lastname: Bauer
authors.forename: Pk
authors.initials: P
authors.lastname: Gregersen
authors.forename: Tw
authors.initials: T
authors.lastname: Behrens
authors.forename: Ec
authors.initials: E
authors.lastname: Baechler
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D007370:Interferon Type I / Q000235:genetics / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000276:immunology* / Q000503:physiopathology; D046228:Microarray Analysis; D008875:Middle Aged; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D007370:Interferon Type I