RT Journal Article SR Electronic T1 The impact of rheumatoid factor and ACPA on bone erosion in rheumatoid arthritis JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP e4 OP e4 DO 10.1136/annrheumdis-2014-206631 VO 74 IS 1 A1 Carolin Hecht A1 Georg Schett A1 Stephanie Finzel YR 2015 UL http://ard.bmj.com/content/74/1/e4.abstract AB