Reference ranges for hemoglobin variants by HPLC in African Americans

Area of Science:

• Hematology
• Clinical Chemistry

Background:

• Conventional methods for hemoglobinopathy screening have limitations.
• High performance liquid chromatography (HPLC) offers advantages for identifying hemoglobin variants.
• There is a need to establish HPLC-specific hemoglobin reference ranges for diverse populations.

Purpose of the Study:

• To determine HPLC-based hemoglobin reference ranges for normal African American adults and newborns.
• To provide updated quantitation data for hemoglobin A (Hb A), Hb A1, Hb F, and Hb A2.
• To assess the utility of these ranges in identifying common hemoglobin variants.

Main Methods:

• Utilized high performance liquid chromatography (HPLC) for hemoglobin analysis.
• Analyzed blood samples from 200 normal African American adults.
• Analyzed blood samples from 99 normal African American newborns and babies at different ages.

Main Results:

• Established HPLC reference ranges for adults: Hb A (89.8-95.2%), Hb A1 (0.8-5.2%), Hb F (1.7-5.3%), Hb A2 (0.5-3.4%).
• Documented fluctuating ranges for newborns: Hb F (66.6-89.9% at 4 days to 9.3-22.8% at 300 days), Hb A (10.1-33.4% at 4 days to 76.4-90.7% at 300 days).
• Observed consistent A/S and A/C ratios (1.0-2.2) for common variants (Hb AS, Hb AC, Hb FAS, Hb FAC) across age groups.

Conclusions:

• HPLC provides reliable hemoglobin quantitation and reference ranges for African American populations.
• These established ranges are valuable for accurate hemoglobinopathy screening and variant identification.
• The findings support the broader application of HPLC in clinical diagnostics for hemoglobin disorders.