Thalidomide and thrombosis.

Background. Teratogenicity and neuropathy are the well known serious side e ffects induced by thalidomide. We describe 5 cases of thrombotic events occ urring within a brief delay after the onset of thalidomide in a manner that suggests that thalidomide could have acted as a precipiting or as a starti ng factor in these events. Observations. Five patients including 4 patients with lupus erythematosus ( 1 discoid lupus, 1 subacute lupus and 2 systemic lupus erythematosus) and o ne patient with a severe atopic dermatitis, all without previous history of vascular events, developed an arterial thrombosis (2 cases) or a Venous th rombosis (3 cases), severe in 4 cases, few days or weeks after the onset of thalidomide treatment (50 to loo mg daily). Discussion. All the patients had risk factors of thrombosis: the presence o f antiphospholipids and/or anticardiolipin antibodies in lupus erythematosu s patients and a trauma in the atopic case. However the absence of a previo us story of thrombosis, its rapid occurrence after the onset of thalidomide and its severity are intriguing. In addition, recent studies demonstrate t hat thalidomide has various effects that would act, among other things, on angiogenesis. Thus, we think that a doubt exists on a negative effect of th alidomide in thrombosis risk factors patients and that this hypothesis has to be confirmed.