title: A distinct inflammatory gene expression profile in patients with psoriatic arthritis.
abstract: Psoriatic arthritis (PsA) is a systemic inflammatory condition featuring polyarthritis associated with psoriasis. Apart from clinical indicators, few biomarkers exist to aid in the diagnosis and management of PsA. We hypothesized that whole blood gene expression profiling would provide new diagnostic markers and/or insights into pathogenesis of the disease. We compared whole blood gene expression profiles in PsA patients and in age-matched controls. We identified 310 differentially expressed genes, the majority of which are upregulated in PsA patients. The PsA expression profile does not significantly overlap with profiles derived from patients with rheumatoid arthritis or systemic lupus erythematosus. Logistic regression identified two lymphocyte-specific genes (zinc-finger protein 395 and phosphoinositide-3-kinase 2B) that discriminate PsA patients from normal controls. In addition, a highly coregulated cluster of overexpressed genes implicated in protein kinase A regulation strongly correlates with erythrocyte sedimentation rate. Other clusters of coregulated, yet suppressed genes in PsA patient blood include molecules involved in T-cell signaling. Finally, differentially expressed genes in PsA fall into diverse functional categories, but many downregulated genes belong to a CD40 signaling pathway. Together, the data suggest that gene expression profiles of PsA patient blood contain candidate novel disease markers and clues to pathogenesis.
authors.affiliation: Department of Medicine, University of Minnesota Medical School, Center for Immunology, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Stoeckman
authors.forename: E C
authors.initials: EC
authors.lastname: Baechler
authors.forename: W A
authors.initials: WA
authors.lastname: Ortmann
authors.forename: T W
authors.initials: TW
authors.lastname: Behrens
authors.forename: C J
authors.initials: CJ
authors.lastname: Michet
authors.forename: E J
authors.initials: EJ
authors.lastname: Peterson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015535:Arthritis, Psoriatic / Q000235:genetics* / Q000276:immunology*; D016022:Case-Control Studies; D058541:Class II Phosphatidylinositol 3-Kinases; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000276:immunology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D005810:Multigene Family; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D014157:Transcription Factors; C484332:ZNF395 protein, human; D019869:Phosphatidylinositol 3-Kinases; D058541:Class II Phosphatidylinositol 3-Kinases; C502616:PIK3C2B protein, human