Hydroxychloroquine for the First Thrombosis Prevention in Antiphospholipid Antibody Positive Patients

A Prospective Randomized Controlled Trial of Hydroxychloroquine in the Primary Thrombosis Prophylaxis of aPL Positive But Thrombosis-free Patients.

In this multi-center international study, our aim is to determine the effectiveness of HCQ for primary thrombosis prophylaxis in persistently aPL-positive but thrombosis-free patients without systemic autoimmune diseases.

Randomized to receive HCQ or no treatment in addition to their standard regimen. 11 study visits and 10 phone visits over 5 years.

This study was terminated at 2 years due to low recruitment rate exacerbated by manufacturing shortage and price increase of hydroxychloroquine.

Inclusion Criteria:

• Persistent(at least 12 weeks apart)aPL-positivity within 12 months prior to the screening defined as:

  • aCL IgG/M (>40U,medium-to-high titer,and/or greater than the 99th percentile)and/or
  • aβ2GPI IgG/M(>40U, medium-to-high titer, and/or greater than the 99th percentile)and/or
  • Positive LA test based on the International Society of Thrombosis & Haematosis Recommendations

Selected Exclusion Criteria:

• History of thrombosis (arterial, venous, and/or biopsy proven microthrombosis
• History of Transient Ischemic Attack Confirmed by a Neurologist
• SLE Diagnosis based on the ACR Classification Criteria > 4/11
• Other Systemic Autoimmune Diseases diagnosed based on ACR Classification Criteria
• Current Hydroxychloroquine or another antimalarial treatment (-3 months)
• Current warfarin treatment (-3 months)
• Current heparin therapy( -3 months)
• Current pregnancy
• History of Hydroxychloroquine eye toxicity
• History of Hydroxychloroquine allergy
• Known glucose-6-phosphate dehydrogenase deficiency