%0 Journal Article
%T Circulating surfactant protein -D is low and correlates negatively with systemic inflammation in early, untreated rheumatoid arthritis
%A Anne Christensen
%A Grith S£¿rensen
%A Kim H£¿rslev-Petersen
%A Uffe Holmskov
%A Hanne Lindegaard
%A Kirsten Junker
%A Merete Hetland
%A Kristian Stengaard-Pedersen
%A S£¿ren Jacobsen
%A Tine Lottenburger
%A Torkell Ellingsen
%A Lis Andersen
%A Ib Hansen
%A Henrik Skj£¿dt
%A Jens Pedersen
%A Ulrik Lauridsen
%A Anders Svendsen
%A Ulrik Tarp
%A Jan P£¿denphant
%A Aage Vestergaard
%A Anne Jurik
%A Mikkel £¿stergaard
%A Peter Junker
%J Arthritis Research & Therapy
%D 2010
%I BioMed Central
%R 10.1186/ar2948
%X One-hundred-and-sixty disease-modifying antirheumatic drug (DMARD) na£¿ve RA patients with disease duration less than six months were studied prospectively for four years (CIMESTRA (Ciclosporine, Methotrexate, Steroid in RA) trial) including disease activity measures (C-reactive protein, joint counts and Health Assessment Questionnaire (HAQ) score), autoantibodies, x-ray findings and SP-D. SP-D was quantified by enzyme-linked immunosorbent assay (ELISA) and molecular size distribution was assessed by gel filtration chromatography. Further, SP-D Met11Thr single nucleotide polymorphism (SNP) analysis was performed.Serum SP-D was significantly lower in RA patients at baseline compared with healthy controls (P < 0.001). SP-D increased slightly during follow-up (P < 0.001), but was still subnormal at four years after adjustment for confounders (P < 0.001). SP-D in synovial fluid was up to 2.5-fold lower than in serum. While multimeric variants were detected in serum, SP-D in synovial fluid comprised trimeric subunits only. There were no significant associations between genotype distribution and SP-D. Baseline SP-D was inversely associated to CRP and HAQ score. A similar relationship was observed regarding temporal changes in SP-D and CRP (zero to four years). SP-D was not associated to x-ray findings.This study confirms that circulating SP-D is persistently subnormal in early and untreated RA despite a favourable therapeutic response obtained during four years of follow-up. SP-D correlated negatively to disease activity measures, but was not correlated with x-ray progression or SP-D genotype. These observations suggest that SP-D is implicated in RA pathogenesis at the protein level. The exclusive presence of trimeric SP-D in affected joints may contribute to the maintenance of joint inflammation.(j.nr NCT00209859).Within recent years, search for innate immune system abnormalities in rheumatoid arthritis (RA) has attracted considerable attention [1]. Thus, low serum levels
%U http://arthritis-research.com/content/12/2/R39