Influence of the reticulocyte crisis in the healing phase of megaloblastic anemias following transfusion

: The numerical behaviour of the leucocytes, thrombocytes and reticulocytes of 12 patients with megaloblastic anaemia before and after additional transfusion as well as after following parenteral therapy with vitamin B12 was investigated. Transfusions alone had no influence on the numbers of leukocytes thrombocytes and reticulocytes. After 4--5 days vitamin B12 led to a very inhibited crisis of reticulocytes in 9 of the 12 patients, in the others an increase did not take place. Thrombocytes and leukocytes appeared partly in form of a crisis in all patients after 6 to 9 days with normalisation of the values, latest after 14 days. The very reduced or lacking crisis of reticulocytes after treatment with vitamin B12 due to previous additional transfusion was discussed.