Neonatal screening for haemoglobin variants using filter paper-dried blood specimens.

Area of Science:

• Medical Diagnostics
• Biochemistry
• Public Health

Background:

• Neonatal screening for haemoglobinopathies is crucial for early diagnosis and management.
• Current cord blood screening methods have limitations, including high miss rates and maternal sample contamination.
• Dried Guthrie card samples offer an alternative collection method, avoiding issues associated with cord blood.

Purpose of the Study:

• To evaluate Iso-electric focusing (IEF) for analysing dried Guthrie card samples for haemoglobinopathies.
• To compare IEF results with established cellulose acetate/citrate agar electrophoresis methods.
• To assess the utility of the JOSHUA enzyme-linked immunosorbent assay (ELISA) for sickle cell trait confirmation.

Main Methods:

• Analysis of 2406 dried Guthrie card samples using Iso-electric focusing (IEF).
• Comparison of IEF results with cellulose acetate/citrate agar electrophoresis of liquid cord blood samples.
• Evaluation of the JOSHUA enzyme-linked immunosorbent assay (ELISA) for haemoglobin S detection.

Main Results:

• Iso-electric focusing (IEF) demonstrated excellent correlation with cellulose acetate/citrate agar electrophoresis.
• IEF analysis provided clear and easily interpretable results, even after 4 weeks of room temperature storage.
• The JOSHUA ELISA reliably detected haemoglobin S in dried specimens, confirming sickle cell trait.

Conclusions:

• Dried Guthrie card analysis via Iso-electric focusing (IEF) is a reliable method for neonatal haemoglobinopathy screening.
• IEF offers a practical and interpretable alternative to traditional methods for dried samples.
• The JOSHUA ELISA is a cost-effective and simple tool for confirming sickle cell trait in neonatal screening programs using dried specimens.