Serum Growth Differentiation Factor-15 (GDF-15) Level in Behcet's Disease Patients: Relation to Clinical Characteristics, Musculoskeletal Ultrasound Findings and Disease Activity

Aim of the work: This study was conducted to assess serum level of growth differentiation factor-15(GDF-15) in Behcet's disease (BD) patients and its relationship with clinical characteristics, ultrasound findings and disease activity. Patients and methods: Study included 30 BD patients and 20 matched healthy controls. Visual analog scale (VAS)-pain of affected joints and Behcet's disease current activity form (BDCAF) were assessed. The most affected joints and surrounding soft tissues were assessed by musculoskeletal ultrasound (MSUS). Serum GDF-15 level was measured. Results: Patients were 23 males and 7 females (M:F 3.3:1) with a mean age of 34.6 +/- 8.6 years and mean disease duration of 6.6 +/- 4.5 years. 18(60%) had arthritis and arthralgia. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were 26.2 +/- 21.2 mm/1sthr and 50.4 +/- 37 mg/dl respectively. There was significant increase of GDF-15 levels in patients with articular affection (3492.3 +/- 4618.8 ng/ml) compared to those without (338.9 +/- 90.3 ng/ml) and controls (322 +/- 78.8 ng/ml) (p < 0.001). As regard MSUS, knee (n = 8) and ankle joints (n = 8) were the most commonly affected joints. Synovitis was present in 13 patients, enthesopathy was present in 10. GDF-15 significantly correlated with ESR and CRP (r = 0.48;p = 0.008 and r = 0.73, p = 0.005) and both remained significant on regression analysis that ESR (p = 0.019 and p = 0.007 respectively). At a serum GDF-15 cut-off point of 570 ng/ml for patients with peripheral arthritis/arthralgia the sensitivity and specificity were 88.9% and 91.7% respectively. Conclusion: Serum GDF-15 can be used as a marker for articular affection in BD patients and is associated with the MSUS imaging visualizing subclinical inflammatory changes. (C) 2021 Egyptian Society of Rheumatic Diseases. Publishing services provided by Elsevier B.V.