title: Baseline JAK phosphorylation profile of peripheral blood leukocytes, studied by whole blood phosphospecific flow cytometry, is associated with 1-year treatment response in early rheumatoid arthritis.
abstract: We found recently that baseline signal transducer and activator of transcription 3 phosphorylation in peripheral blood CD4+T cells of patients with early rheumatoid arthritis (RA) is associated with treatment response to synthetic disease-modifying antirheumatic drugs (DMARDs). This prompted us to study the baseline phosphorylation profiles of Janus kinases (JAKs) in blood leukocytes with respect to treatment response in early RA.
  
  
  
  Thirty-five DMARD-naïve patients with early RA provided blood samples for whole blood flow cytometric determination of phosphorylation of JAKs in CD4+and CD8+T cells, CD19+B cells, and CD14+monocytes. Treatment response was determined after 1 year of treatment with synthetic DMARDs, with remission defined as absence of tender and swollen joints and normal erythrocyte sedimentation rate. Exact logistic regression was used to investigate the association of baseline variables with treatment response. Ninety-five percent CIs of means were estimated by bias-corrected bootstrapping.
  
  
  
  High JAK3 phosphorylation in CD4+and CD8+T cells, CD19+B cells, and CD14+monocytes and low JAK2 phosphorylation in CD14+monocytes were significantly associated with remission following treatment with synthetic DMARDs.
  
  
  
  Baseline JAK phosphorylation profile in peripheral blood leukocytes may provide a means to predict treatment response achieved by synthetic DMARDs among patients with early RA.
authors.affiliation: Bacteriology and Immunology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland. krista.kuuliala@helsinki.fi.
authors.forename: Krista
authors.initials: K
authors.lastname: Kuuliala
authors.affiliation: Bacteriology and Immunology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Kuuliala
authors.affiliation: Rheumatology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Koivuniemi
authors.affiliation: Primary Health Care, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.|General Practice, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.|Unit of Primary Health Care, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Hannu
authors.initials: H
authors.lastname: Kautiainen
authors.affiliation: Bacteriology and Immunology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Repo
authors.affiliation: Rheumatology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
authors.forename: Marjatta
authors.initials: M
authors.lastname: Leirisalo-Repo
mesh_terms: D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D053612:Janus Kinases / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism; D010766:Phosphorylation
chemical_list: D018501:Antirheumatic Agents; D015415:Biomarkers; D053612:Janus Kinases
keywords: Biomarker; Blood; Disease-modifying antirheumatic drug; Janus kinases; Leukocyte; Phosphorylation; Rheumatoid arthritis