Background The association between MRI inflammation and bone loss in early axial spondyloarthritis (axSpA) patients is not sufficiently studied.
Objectives Establishing the association between MRI inflammation of sacroiliac joints (SIJs), lumbar spine (LS) and hip joints (HJs) and bone loss in the nearby bone-joint system in early axial axSpA patients.
Methods 73 patients (33 men and 40 women) with early axSpa were examined: mean disease duration 19.9±14.4 months. Patients fulfilled ASAS criteria. Mean age 28.3±6.4 years, mean BASDAI 4.1±1.9; mean ASDAS-CRP 2.7±1.3; mean ESR 21.9±17.6; mean CRP 29.0±38.5; 66 (90.4%) patients were HLA-B27 positive. MRI of SIJs, LS and HJs (in case of hip joint involvement) was performed on Signa Ovation 0.35 T scanner (matrix 288x192). BMD was measured using dual energy x-ray absorptiometry (DXA) of the femoral neck (FN) and lumbar spine (LS) (L2–4). BMD reduction was defined as T score ≤−1.
Results MRI inflammation of SIJs and/or LS and/or HJs has been found in 62 (84.9%) patients. Among the 62 patients of this group 44 (71.0%) had BMD reduction in FN and/or LS. And in the group of patients without MRI inflammation (n=11) nobody had bone loss (p=0.0001).
MRI sacroiliitis (SI) was observed in 53 (72.6%) patients: 37 (69.8%) of them had BMD reduction in FN and/or LS, and 16 (30.2%) patients of this group had normal BMD values (p=0.007).
MRI SI has been found in 32 out of 37 (86.5%) patients that had BMD reduction in the LS; in the group of patients without bone loss in the LS (n=36) MRI SI was observed in 21 (58.3%) patients (p=0.007).
MRI SI has been found in 21 out of 27 (77.8%) patients that had BMD reduction in the FN; in the group of patients without bone loss in the FN (n=46) MRI SI was observed in 32 (69.6%) patients (p=0.45).
Conclusions Correlation has been detected between inflammatory lesions in SIJs and/or LS and/or HJs and bone loss in FN and/or LS. There is an association between existence of active MRI SI and BMD reduction in the LS. This demonstrates that in patients with early axSpA bone loss is a result of inflammation.
Disclosure of Interest None declared