FRI0517 Early metacarpal bone mineral density loss is predictive for radiologic joint damage progression after 1 year in patients with early arthritis

Background In patients with established RA, radiological progression is preceded by metacarpal bone mineral density (mBMD) loss. Objectives To assess whether in early (rheumatoid) arthritis patients, mBMD loss after 4 months is an independent predictor for radiological progression after 1 year of antirheumatic treatment. Methods mBMD was measured in metacarpals 2-4 by digital X-ray radiogrammetry (DXR) in patients participating in the IMPROVED study, a single blind multicenter study in 479(79%) RA (2010 ACR/EULAR criteria, symptom duration 1 joint, at risk for developing RA by rheumatologists estimation but not fulfilling the 2010 criteria) patients. All patients started treatment with 4 months of methotrexate (MTX) and a tapered high dose of prednisone, followed by tapering or adjusting treatment aiming at DAS Results Of 237 patients (43(18%) UA, 192(81%) RA, 2 missing classification) mBMD measurements at baseline and 4 months and radiological progression data after 1 year were available. Median mBMD loss after 4 months (4mo-mBMD loss, mg/cm 2 unless indicated otherwise) was 2.3(-1.7 to 6.8) (corresponding to 0.6(-0.4 to 1.7) mg/cm 2 /month). Seventeen (7%) patients had radiological progression after 1 year and 220(93%) had not. Patients with radiological progression had a median (IQR) 4mo-mBMD loss of 5.5(2.7 to 13.6) compared to 2.0(-2.0 to 6.6) in patients without progression (corresponding to 1.4(0.7 to 3.4) and 0.5(-0.5 to 1.6) mg/cm 2 /month), (p=0.002). Univariable predictors for progression (OR (95%CI) were age (1.0(1.0-1.1)), fulfilling the 2010 criteria for RA (6.4(0.9-48)), postmenopausal status (6.2(1.4-27)), ESR (1.0(0.999-1.0)), tSHS (1.1(0.996-1.1)), presence of erosions (4.4(2.0-10.0)) and presence of ACPA (3.5(1.3-9.4)), all at baseline, and 4mo-mBMD loss (mg/cm 2 /months) (1.5(1.2-1.9)). Female gender, RF positivity, symptom duration, baseline swollen and tender joint counts were not predictive. Independent predictors for progression after 1 year were presence of baseline erosions (5.2(1.7-16)) and 4mo-mBMD loss (mg/cm 2 /month) (1.5(1.1-2.0)). In 203(86%) patients who had no erosions at baseline, 4mo-mBMD loss (mg/cm 2 /month) was the only independent predictor for progression after 1 year (1.8(1.3-2.7), adjusted for age). Conclusions In early (rheumatoid) arthritis patients, mBMD loss after 4 months of MTX and prednisone is an independent predictor for radiological joint damage progression, despite the fact that radiological progression was only present in 7% of patients after 1 year of a remission steered treatment strategy. In particular in patients who are non-erosive at baseline, mBMD loss after 4 months may help to steer treatment decisions as predictor of damage progression. Disclosure of Interest None Declared