FRI0185 HYDROXYCHLOROQUINE FOR THE PREVENTION OF RELAPSES IN A SERIES OF 812 PATIENTS WITH PRIMARY ANTIPHOSPHOLIPID SYNDROME: THE HIBISCUS RETROSPECTIVE STUDY

Abstract

Background: The relapse rate in antiphospholipid syndrome (APS) remains high, 20% at 5 years in thrombotic APS and 28% in obstetrical APS (1). Hydroxychloroquine (HCQ) appears as an additional therapy, with immunomodulatory and antithrombotic effects (2-5). Objectives: The main aim of this trial is to assess the efficacy of treatment with Hydroxychloroquine in preventing new events in primary antiphospholipid syndrome patients. Methods: We have performed a retrospective multicentre open-labelled study (2002-2018). Results: 812 patients with APS from 53 international centres from 16 countries were included. In all cases, the previous standard treatment was inefficient. The mean follow-up was 20.2 months (8- 144 mo), the mean age 39.5 years old. The type of clinical manifestations is described in figure 1. The obstetrical manifestations were various as described in figure 2. The number of thrombotic events were 190 arterial and 187 venous. Triple antiphospholipid antibody (tAPL) positivity was found in 20% of patients and lupus anticoagulant (LA) in 22%. No bleeding was registered in 99,6% of cases with treatment by HCQ. HCQ use was associated with favourable outcome in 96% of cases (figure 3). In multivariate analysis, age more than 65 years was associated with arterial events (odds-ratio 0.13 95%CI 0.03-0.32, p 0.005). Conclusion: HCQ could be effective in cases of refractory APS but prospective studies are necessary.