[Venous thrombosis, circulating anticoagulant and systemic lupus erythematosus. Two cases reported in two identical HLA sisters (author's transl)].

The observation of two cases of thrombophlebitis of the calf which occurred in two sisters within a period of three years is reported. The investigation revealed in both cases the presence of a circulating anticoagulant with anti-prothrombinase activity in association with biological signs of systemic lupus erythematosus (L.E.