Background/Purpose To determine the prospective clinical course of lower extremity deep vein thrombosis (LEDVT) in patients with Behçet’s syndrome (BS). 

Methods Consecutive BS patients with an acute episode of LEDVT were prospectively studied.  Clinical examination and lower extremity Doppler ultrasonography (US) were done at 1, 3, 6, 18 and 24 months after the index event. A relapse was defined as a new episode of LEDTV and/or a superficial vein thrombosis (SVT). 

Results

40 patients (6F, 34M) with LEDVT were followed for a mean= 33.2±10.8 months.  The mean age was 30.2±7.3, and the median disease duration since disease onset was 33.3 months (IQR=8.0-60.8). A total of 50 relapses were observed in 27 patients. This was in the form of solo SVT in 8 patients, solo LEDVT in 10 and LEDV+SVT in 9 patients. Cox regression analysis revealed that a recanalization rate of ≥ 50% in LEDVT observed by US at month 3 was significantly associated with a lower relapse rate (HR= 0.23; 95% CI =0.092-0.59). 

The first line treatment had been with azathioprine (AZA) with moderate doses of glucocorticoids (0.5 mg/kg/d) in 34 (85%) patients, interferon-alpha (IFN-alpha) in 4 and cyclophosphamide in 2 patients (also with pulmonary vasculitis). 19 out of 34 (55%) remained on AZA, 10 were switched to IFN-alpha for resistant or recurrent disease during  follow up. 8 of these 10 patients did not experience relapses after switching to IFN-alpha. 16 patients treated with IFN-alpha (including 3/4 initially treated with IFN-alpha) during follow-up and 12 of 16 (75%) patients were still on IFN-alpha therapy without relapses. 

Conclusion Relapses and resistant disease are frequent 27/40 (67.5%) in LEDTV in BS and is significantly associated with a failure to recanalize at 3 months.  IFN-alpha can justifiably be tried in the treatment of LEDVT, refractory to AZA and glucocorticoid use.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-clinical-course-of-acute-deep-vein-thrombosis-of-the-legs-in-behcets-syndrome/