Hemoglobin fractions in Indian pediatric population – Do we need to look westward?

Abstract

BACKGROUND: Hemoglobin (Hb) is a tetramer of two alpha and two beta globin polypeptide chains, The fractions of HbF, HbA2, and HbA vary gradually in pediatric population (age 0–12 years) and show a dynamic change in the 1st year of life. OBJECTIVE: The objective of the study is to establish the levels of normal hemoglobin (Hb) fractions by using high-performance liquid chromatography (HPLC) in Indian pediatric population. MATERIALS AND METHODS: A total of 169 children of 0–12 years of age were recruited from a pediatric outpatient clinic. Eleven cord blood samples from normal deliveries were collected, and 2 ml peripheral blood was drawn from each subject in EDTA vial for CBC and Hb HPLC. CBC was performed by hematology analyzer XT 2000i, and the proportion of HbA, HbA2, and HbF was obtained from HPLC using the β thalassemia short program. RESULTS: The fractions of HbF, HbA2, and HbA gradually changed with increasing age. HbF levels decreased rapidly from 80.9% ± 0.48% (mean ± standard deviation) in the cord blood to 3.6% ± 1.04% at 6 months of age. HbA2 was 0% in cord blood, was 0.04 ± 0.12 in newborn, reached to a level of 2.52% ± 0.3% at 6–12 months of age, and thereafter marginally increased to 2.65 ± 0.89% at 2–12 years of age. HbA was 20.41% ± 5.14% in the cord blood and increased substantially to 84.7% ± 1.83% at 6–12 months of age. CONCLUSION: HbF levels show a more dynamic change in the first 6 months of life than later half. It reaches adult levels by the age of 2 years. HbA2 levels reach a plateau at 6 months of age. HbA levels rise substantially until the 6th month and sustain thereafter. These data can serve as a quick practical reference guide for the analysis of Hb fractions in the Indian pediatric population.

Keywords

• hemoglobin
• high-performance liquid chromatography
• newborn screening
• pediatrics