Effect of Transfusion on Hemoglobin Variants in Preterm Infants

Abstract

OBJECTIVE:To determine the effect of transfusion on hemoglobin (Hb) variants in very low birth weight infants and to correlate these changes with parameters measured in routine complete blood counts. METHODS:Hb variants were measured by capillary isoelectric focusing on 126 specimens from 25 very low birth weight infants during their hospital course. These results were compared with transfusion frequency, mean corpuscular volume (MCV), and red cell distribution width. RESULTS:Mean initial Hb F level before transfusion was 87.1 Ϯ 5.1%, and a single 15 ml/kg packed red blood cell transfusion decreased the mean Hb F level to 54.0 Ϯ 4.7%. With frequent transfusions in the first month of life, there was progressive decline in Hb F content such that Hb F made up Ͻ15% of the total Hb after five transfusions. There was a linear correlation between Hb F content and MCV, with a correlation coefficient (r) of 0.77 and a p value of Ͻ0.0001. In most instances, when the MCV fell below 100 fl, the Hb F content was Ͻ50%; when the MCV fell below 95 fl, the Hb F content was Ͻ25%. There was a nonlinear correlation between Hb F content and red cell distribution width. CONCLUSION:Transfusion in very low birth weight infants results in a rapid transition from Hb F to Hb A predominance. This transition is marked by a reduction in MCV that allows for prediction of the Hb F content.

Duration of neonatal oxygen supplementation, erythropoiesis and blood pressure in young adults born preterm

“…Preterm birth is associated with an abrupt and early transition to ex utero environment, with blood oxygen saturation levels increasing rapidly from physiological fetal levels (45%–55%) to adult values 23. Early exposure to higher oxygen concentrations, neonatal oxygen supplementation and repeated adult red blood cell transfusions that result in a transition from fetal to adult haemoglobin predominance (with a different O 2 affinity) in early life24 may durably alter oxygen-sensing pathways in preterm neonates that could result in a long-term upregulation of erythropoiesis in individuals born preterm. Since red blood cell transfusions in the neonatal period and duration of neonatal oxygen supplementation were associated with each other, the observational nature of our study does not allow to distinguish the effects of these factors separately.…”

The Role of Hemoglobin Variant Replacement in Retinopathy of Prematurity

“…The physiological content of hemoglobin F (HbF) of over 90% in that period of life is replaced by HbA, resulting in a dissociation curve shift, which can be responsible for oxygen toxicity [7,[12][13][14].…”

“…It has been shown that after five transfusions in infants, the hemoglobin F (HbF) level declines to below 15% of the total hemoglobin, compared with 87.1±5.1% before transfusion [12]. This change affects the hemoglobin oxygen dissociation curve and results in increased oxygen toxicity during this period of life [13,14].…”

“…MCV depends on and indirectly indicates the HbF content [12]. The authors have tested relationship between severity of ROP and gender too.…”

Recent applications of capillary isoelectric focusing

“…A convenient CIEF system applying the standard two-step CIEF technique with pressure mobilization was used to analyze both Hb and globin chain variants [36][37][38]. The isoelectric points of the hemoglobin variants were determined and used for identification in CIEF applying external standards [39].…”