Background 10-62% of Inflammatory Bowel Disease (IBD) patients have musculoskeletal manifestations, characterized by the appearance of peripheral arthritis, axial disease and enthesitis, mainly. Ultrasonography is more sensitive than physical examination to detect enthesopathy, so it may be useful to identify subclinical entheseal involvement.
Objectives To evaluate the presence of enthesitis with power Doppler ultrasonography (PDUS) in IBD patients without clinically evident musculoskeletal disease and to investigate its correlation with IBD variables.
Methods Cross-sectional study that recruited prospectively IBD patients, without clinically overt musculoskeletal disease, attended by Gastroenterology during 2013. Gastroenterological, rheumatological and PDUS evaluation, blind to each other, were performed. Clinical assessment included demographics, comorbidities, IBD characteristics (activity, phenotype, evolution time and clinical subtype), work and sport activities and musculoskeletal clinical examination. PDUS evaluation consisted of the detection of grey scale (GS) enthesopathy and entheseal power Doppler (PD) signal in 12 enthesis (bilateral triceps, cuadriceps, proximal and distal patellar, Achilles and plantar fascia enthesis), scored according to the Madrid Ankylosing Spondylitis Enthesitis Index (MASEI), using a LOGIQ7 General Electric machine with a 12-MHz linear array transducer. Statistical analysis: continuous variables are expressed as mean ± SD or range and categorical variables as number of cases (%). The associations between PDUS and clinical variables were evaluated by the Student's t test and Mann-Whitney test for continuous variables and by the χ2 test for categorical ones. Pearson and Spearman correlations of PDUS with clinical and analytical variables were also analyzed. The intra-reader agreement for US was estimated in all the images obtained. Statistical significance was set at p<0.05 (Stata 10).
Results 23 (56.5% male) IBD patients [9 Crohn's disease (CD) and 14 ulcerative colitis (UC)] have been included so far. Clinical variables: Age 42±12 years, evolution time 9 years (range: 0.1-33), CDAI 28±21, Mayo index 0.4±1, DMARD therapy in 91.3% for 5.5±5.3 years, ESR 12±8.8 mm/h and CRP 0.12±0.14 mg/dL. A positive MASEI (>20) was present in 95.7%, with a mean score of 35.2±9.5. GS enthesal abnormalities were found in at least 1 enthesis in 100% of patients: enthesophytes or calcifications (100%), altered echoestructure (100%), increased thickness (100%), erosion (13%) and bursitis (34.8%). Enthesophytes and calcifications were mild, moderate and severe in 60.9%, 26.1% and 13% of patients, respectively. PD signal was positive in 52.2% of patients. We found no association between PDUS variables and clinical or analytical IBD variables, probably due to the yet small sample size. The intra-reader agreement was high (0.8 intra-class correlation variability).
Conclusions Subclinical articular and entheseal PDUS abnormalities are frequently present in IBD patients, independently of activity, evolution time and clinical subtype. Their predictive value of clinically overt musculoskeletal disease should be investigated in prospective longitudinal studies.
Disclosure of Interest None declared