AIM AND TASKS: The major gene regulating erythropoietin /EPO/ synthesis is hypoxia induced factor/HIF/. Proceeding from the assumption that the transfusions /HT/ remove hypoxia due to anemia and inactivate HIF, the aim of the study was to show the decreased activity of erythropoiesis after HT MATERIALS AND METHODS:
Patients: 40 premature infants <34 g.a. and birth weight < 1400 g with anemia of prematurity. We analyzed: Hb /g/I/, Ht%, Thrx 10(9)/I, Ret%, 24-48 hours and 7-10 days after HT The dynamics of changes of blood lactate /mmol/l/level after HT was used as an indirect index of relative hypoxia/activated HIF/. The changes of Hb /g/l/ and Ht% determined the need of haemotransfusions.
Results: After HT along with the increase of Hb from 89, 7+/-10,0 to 119+/-13,3, there was significant decrease in Ret % from 2,4+/-1,1 to 1,4+/-0,5 7-10 day after HT There was also a reduction of Thr from 391,5+/-131,5 to 250, 7+/-57,2 and blood lactate in mmol/l from 2,5+/-1,1 to 1,5+/-0,7. The study showed that 7-10 days after HT the values of Hb and Ht decreased to baseline levels, that required new transfusion.
Conclusion: Transfusion of packed red blood cells in patients with anemia of prematurity suppresses erythropoiesis, which is demonstrated by the significant reduction in reticulocyte count. The decreased level of blood lactate after HT shows elimination of the relative hypoxia that is required for hypoxia- induced expression of HIF and erythropoietin synthesis.