Drug treatment-induced downregulation of antiphospholipid antibodies in PAPS.

Although low-dose methotrexate (MTX) has been used to treat several autoimmune diseases like lupus erythematosus, rheumatoid arthritis, etc., it has not yet been used to treat patients with primary antiphospholipid syndrome (PAPS). Parallel to clinical follow-up of female patient with a severe form of PAPS, antiphospholipid antibodies (aPL), blood coagulation, and hematological parameters in the peripheral blood have been monitored. MTX improved ulcers, livedo reticularis, decreased aPL titers, increased platelet counts, and improved blood coagulation parameters (e.g., factor VIII) and was well tolerated. Low-dose MTX was safe and effective in the presented case with PAPS. The clinical benefit may be due to the downregulation of increased aPL titers and amelioration of disturbed coagulation parameters.