[Fetal hemoglobin in the blood in leukemia].

Haemoglobin F was determined in 19 patients with leukemia: 12 with LAM, 4 with LAL, 2 with LLC and 1 with LMC. Half of the patients with acute leukaemia was in remission and other half in evolution at the time of the study, later ones having anemia. Haemoglobin F was determined by the alcali resistance method. In 10 control cases haemoglobin F was 0.98 +/- 0.48%. Increased level of haemoglobin F was found in 7/12 LAM and 2/4 LAL patients. Eight of those 9 patients with increased haemoglobin F level were in remission and in one not in remission refrectary anaemia preceded LAM. The results presented indicate that during the recovery of erythropoiesis, some erythroblasts synthetize haemoglobin F. Those erythroblasts are probably the progeny of erythroid stem cells which during differentiation and proliferation "skipp" some maturation stages.