Differences in bone structure between rheumatoid arthritis and psoriatic arthritis patients relative to autoantibody positivity.
OBJECTIVE
To investigate whether trabecular and cortical bone structure differ between patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA). So far, no study has performed a detailed comparative analysis of bone structure in patients with RA and PsA.


METHODS
110 patients (60 RA, 50 PsA) received high-resolution peripheral quantitative CT of the distal radius. Demographic and disease-specific parameters including anti-rheumatic treatment, bone erosion status and previous fractures were recorded.


RESULTS
RA and PsA patients were comparable in age, gender, body mass index, disease duration, disease activity, functional status, antirheumatic treatment and bone erosion status. No significant differences were found for volumetric bone mineral density (BMD), including total BMD (300±77 vs 316±62 mgHA/cm(3)), trabecular BMD (152±46 vs 165±40 mgHA/cm(3)) and cortical BMD (787±113 vs 818±76 mgHA/cm(3)) when comparing RA patients to PsA patients, respectively. However, in contrast to seronegative RA, seropositive RA showed significantly reduced trabecular BMD (p=0.007), bone volume per tissue volume (p=0.007) and trabecular number (p=0.044), as well as a strong trend towards higher trabecular inhomogeneity compared to PsA patients. In the regression analysis, higher age, female gender and presence of autoantibodies were independently associated with trabecular bone loss.


CONCLUSIONS
Seropositive RA exhibits more profound changes in trabecular bone architecture than seronegative RA or PsA. The data support the concept that seropositive RA is a disease entity that is distinct from seronegative RA and PsA.
Department of Internal Medicine 3 and Institute of Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany St. Vincent Hospital - Medical Department II, The VINFORCE Study Group, Academic Teaching Hospital of Medical University of Vienna, Austria.
Roland
R
Kocijan
Department of Internal Medicine 3 and Institute of Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany.
Stephanie
S
Finzel
Department of Internal Medicine 3 and Institute of Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany.
Matthias
M
Englbrecht
Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany.
Klaus
K
Engelke
Department of Internal Medicine 3 and Institute of Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany.
Juergen
J
Rech
Department of Internal Medicine 3 and Institute of Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany.
Georg
G
Schett
D000328:Adult; D000367:Age Factors; D000368:Aged; D015535:Arthritis, Psoriatic / Q000150:complications* / Q000000981:diagnostic imaging / Q000276:immunology / Q000503:physiopathology; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000000981:diagnostic imaging / Q000276:immunology / Q000503:physiopathology; D001323:Autoantibodies / Q000097:blood*; D015519:Bone Density / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000276:immunology / Q000503:physiopathology; D011884:Radius / Q000000981:diagnostic imaging / Q000503:physiopathology; D012044:Regression Analysis; D012737:Sex Factors; D014057:Tomography, X-Ray Computed / Q000379:methods
D001323:Autoantibodies
Bone Mineral Density; Osteoporosis; Psoriatic Arthritis; Rheumatoid Arthritis