title: Discrepancies in assessment of patients with rheumatoid arthritis and secondary Sjögren's syndrome by DAS28-ESR and DAS28-CRP.
abstract: OBJECTIVE
  To investigate whether a difference exists between DAS28 from CRP and DAS28 from ESR in patients with rheumatoid arthritis (RA) and secondary Sjögren's syndrome (sSS).
  
  
  METHODS
  One group comprised patients with RA and sSS, the control group comprised patients with RA. The inclusion criteria for the RA and sSS group have been specified as follows: presence of at least one symptom of dryness, and also presence of anti-SS-A and anti-SS-B or at least focus score of one in biopsy.
  
  
  RESULTS
  The disease activity score 28 (DAS28) was assessed using both ESR and CRP in 60 patients with RA and sSS and 59 patients with RA alone. However, concordance between these two methods was good (Cohen's κ coefficient κ = 0.60, 95% CI: 0.45-0.75 in the first group and κ = 0.71, 95% CI: 0.56-0.86 in the control group). In the group with RA and sSS, the mean value of DAS28-ESR = 5.2, whereas the mean value of DAS28-CRP = 4.7 (p < 0.0001). In the group with RA alone, mean DAS28-ESR = 4.7 while mean DAS28-CRP = 4.6; no significant difference was identified. Moreover, in RA patients with sSS, mean ESR = 39 mm/h compared with mean CRP at 25 mg/l. 79% of all patients demonstrated dysproteinaemia. There were connections between higher ESR and dysproteinaemia. In the control group there was no statistically significant difference between CRP and ESR.
  
  
  CONCLUSIONS
  Both DAS28-ESR and DAS28-CRP are useful outcome measures in RA. However, in patients with RA and sSS, DAS28 should be evaluated based on CRP.
authors.affiliation: Department of General and Experimental Pathology, Warsaw Medical University, Warsaw, Poland; Department and Polyclinic of Systemic Connective Tissue Diseases, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Romanowska-Próchnicka
authors.affiliation: Department of General and Experimental Pathology, Warsaw Medical University, Warsaw, Poland.
authors.forename: Marzena
authors.initials: M
authors.lastname: Olesińska
authors.affiliation: Department of Biochemistry and Molecular Biology, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Paradowska-Gorycka
authors.affiliation: Department of Epidemiology and Health Promotion, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Mańczak
authors.affiliation: Department of General and Experimental Pathology, Warsaw Medical University, Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Felis-Giemza
authors.affiliation: Department and Polyclinic of Systemic Connective Tissue Diseases, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Wojdasiewicz
authors.affiliation: Department and Polyclinic of Systemic Connective Tissue Diseases, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Szukiewicz
keywords: DAS28-CRP; DAS28-ESR; rheumatoid arthritis; secondary Sjögren's syndrome