Prevention of thrombosis relapse in antiphospholipid syndrome patients refractory to conventional therapy using intravenous immunoglobulin

To investigate the long-term effects of megadoses of intravenous immunoglobulin (IVIG) in a small cohort of patients with relapsing primary APS resistant to conventional treatments.

Five primary APS patients, 4 women, mean age 45.1 years (range 31-76 years), were considered eligible for IVIG therapy due to relapsing thrombotic events (4 recurrent venous thromboses, 2 ischaemic cerebral strokes, 2 pulmonary thromboembolisms, 1 thrombotic event on the vena cava filter), despite conventional therapy with anticoagulants. All patients had anti-nuclear antibodies at low-medium titre without other signs or symptoms of systemic lupus erythematosus. IVIG was combined with hydroxychloroquine and, in patients with cerebral strokes, acetylsalicylic acid. Three consecutive daily infusions of IVIG were administered intravenously at a dose of 0.4 g/kg/day every month for 3 months, followed by a single monthly infusion for 9 months.

No further thromboses occurred in the 5 treated patients (mean follow-up 89.2 months, range 61-114). Visual analogue score (VAS 0-10) improved (mean 3.5, range 3.0-5.0, before, and 7.35, range 9.9-6.0, p= 0.05) after IVIG treatment.

In a long-term (>5 years) open study in a small cohort of high risk primary APS patients, IVIG was found to be effective in preventing recurrent thrombosis. Full understanding of the mechanisms and efficacy, as well as the optimal doses of IVIG in APS patients with recurrent thrombosis, will require appropriately designed clinical studies. Presently, IVIG use is restricted by costs and limited availability.