[Treatment of severe hyperthyroidism by plasma exchange. Clinical and biological efficacy. 8 cases].

The effectiveness of plasmapheresis was evaluated in 8 patients with severe thyrotoxicosis of diverse origin and clinical manifestations, who underwent a total of 22 plasma exchanges. The method proved rapidly effective in controlling the symptoms in 6 cases. No adverse reaction was noted. In all patients plasma exchanges significantly reduced plasma concentrations of total thyroxine and triiodothyronine and of thyroxine-binding globulin, without effect on free thyroxine and triiodothyronine fractions. The satisfactory clinical results obtained can only be explained by displacement of thyroid hormones from the intracellular compartment. The hormonal variations observed were proportional to the initial hormone concentrations, to the amount of thyroxine-binding globulin removed and to the plasma volume purified. It is concluded that plasmapheresis rapidly extracts thyroid hormones and is therefore useful in the treatment of acute severe thyrotoxicosis.