Primary antiphospholipid syndrome (PAPS). Two case reports and therapeutic implications

Antiphospholipid antibodies (aPL) interfere with the coagulation system and can cause thrombosis and other clotting disorders. The combination of recurrent venous thrombosis, arterial embolism and recurrent fetal loss is nowadays considered to be primary antiphospholipid syndrome (PAPS), provided an underlying systemic lupus erythematosus (SLE) has been excluded and aPL have been detected. We report on two patients with PAPs, and show the course of their IgG- and IgM-anticardiolipin antibody (aCL) titers during immunosuppressive therapy with prednisone and azathioprine or cyclophosphamide. Over a period of 18 months this therapy was effective in preventing relapses of thrombo-embolism and other complications. Therapy with cyclophosphamide resulted in normalization of the aCL titers in one of the two reported cases. Azathioprine treatment reduced the aCL titer in the other patient, without fully normalizing it. Based on our observation, we propose to treat PAPS-associated severe and recurrent thrombo-embolic complications by aggressive immunosuppression, including azathioprine and cyclophosphamide.