The author describes the use of a continual COM.TEC Separator of Fresenius Co. in therapeutic cytoreduction erythrocytaphereses in 20 patients. He mentions the balic differences as compared with model Fresenius AS.TEC 204. The apparatus was used for reduction of the erythrocyte volume in polycythemia vera, secondary polyglobulie and haemochromatosis. The collected erythrocyte volumes esere within the range of 628-1472 ml. The author investigated the correlation of the target haematocrit set on the apparatus with the actual haematocrit assessed during the procedures on the haematological analyzer - the mean difference was 2 %. The author did not record any undesirable effects nor side-effects.

        Key words: eerytrocytapheresis, polyglobulie, polycytemia vera, haemochromatosis