Reference intervals for acetylated fetal hemoglobin in healthy newborns

The acetylated fetal hemoglobin (AcHbF) derives from an enzyme-mediated post-translational modification occurring on the N-terminal glycine residues of g-chains. At present, no established data are available on reference intervals for AcHbF in newborns. A total of 92 healthy infants, with gestational age between 37 and 41 weeks were selected for the establishment of AcHbF reference intervals. Blood samples were collected by heel pricking, when collecting routine neonatal screening, and the hemoglobin pattern was analyzed by high-performance liquid chromatography. AcHbF results were then normalized for HbF content in order to account for differences in hemoglobin switch. No difference was found in AcHbF values between genders (P=0.858). AcHbF results were as follow: 12.8±0.8% (mean±standard deviation), reference interval: 11.3-14.3%. This finding could facilitate further studies aimed to assess the possible use of AcHbF, for instance as a possible fetal metabolic biomarker during pregnancy.