Sonographic evaluation of subclinical entheseal involvement in patients with Behçet disease

The aim of the current study was to determine the prevalence of subclinical entheseal involvement in patients with Behçet disease via ultrasound using a newly developed method, the Madrid sonography enthesitis index.

The study was conducted with 36 patients with Behçet disease and 46 healthy sex- and age-matched control subjects. All patients with Behçet disease who had no clinical evidence of arthritis or enthesitis underwent an ultrasound examination. All sonographic findings were identified according to the Madrid sonography enthesitis index. Madrid sonography enthesitis index values of patients and control subjects were compared by Student t test and Mann-Whitney U test. Validity was analyzed by receiver operating characteristic curve.

Total enthesitis score was 12.16 ± 6.16 among patients with Behçet disease and 2.06 ± 2.18 among healthy control subjects (p < 0.001). The receiver operating characteristic curve established an ultrasound score greater than 4.5 in the Behçet disease group as the best cut-off point differentiating case subjects from control subjects. This cutoff was exceeded by 88.8% of the patients with Behçet disease. When the Madrid sonography enthesitis index score in each affected enthesis was evaluated, patients with Behçet disease had significantly higher scores than did control subjects when all entheseal sites were compared (all p values < 0.05).

This is the first study to our knowledge to show significant subclinical enthesopathy of the triceps tendon enthesis in patients with Behçet disease who had no arthritic involvement. These data suggest that the Madrid sonography enthesitis index scoring system for sonographic detection of enthesopathy should be incorporated into the clinical protocol for evaluating patients with Behçet disease in routine clinical practice.