[Presence of subclinical inflammation in axial spondyloarthropathy patients in clinical remission].

OBJECTIVE: To investigate the incidence of bone marrow edema in sacroiliac joint under examination of magnetic resonance imaging (MRI) in patients with axial spondyloarthropathy (SpA) in remission.

METHODS: A total of 87 patients with axial SpA were recruited. Disease activity was assessed by calculation of BASDAI and ASDAScrp scores. All the SpA patients completed MRI scan of sacroiliac joint and bone marrow edema in sacroiliac joint was quantized by SPARCC scoring standard.

RESULTS: According to BASDAI standard (n=87), 60 patients (69.0%) were categorized as remission, of which 40 patients (66.7%) exhibited bone marrow edema in sacroiliac joint (SPARCC>0). 27 patients (31.0%) were categorized as activity, while 23 patients (85.2%) exhibited bone marrow edema in sacroiliac joint (SPARCC>0). According to ASDAScrp standard (n=75), 12 patients (16.0%) were classified as remission, of which 4 patients (33.3%) exhibited bone marrow edema in sacroiliac joint (SPARCC>0). 63 patients (31.0%) were categorized as activity, while 52 patients (82.5%) exhibited bone marrow edema in sacroiliac joint (SPARCC>0). SPARCC score positively correlated with BASDAI (r=0.271, P<0.05), ASDAScrp (r=0.291, P=0.011) and patient global assessment (r=0.414, P<0.01). All the patients were classified as non-regular treatment group, traditional drugs group, and biologics group based on the therapeutic conditions. Percentages of patients with SPARCC>0 in sacroiliac joint were also different among these groups (86.8%, 75.0%, 31.6%, χ(2)=21.483, P<0.01).

CONCLUSIONS: About 1/3 to 2/3 axial SpA patients in clinical remission represent bone marrow edema in sacroiliac joint under MRI examination, which indicates presence of subclinical inflammation in axial SpA with clinical remission. SpA patients treated with biologics could have better remission of radiographic inflammation on MRI.