Related Experiment Video
Updated: Jul 16, 2025
Biochemical Measurement of Neonatal Hypoxia
Published on: August 24, 2011
Performance Comparison Between Conventional Fluorescent Spot Test and Quantitative Assay in Detecting G6PD Deficiency
Sarah Abdul Halim1,2, Rosnah Bahar1,2, Wan Zaidah Abdullah1,2
1Department of Hematology and Transfusion Medicine Unit, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia.
Insights
The fluorescent spot test (FST) misses many cases of Glucose-6-phosphate dehydrogenase (G6PD) deficiency in newborns. The CareStart Biosensor 1 offers a more accurate detection of G6PD deficiency, identifying a higher prevalence.
Area of Science:
- Biochemistry
- Neonatal Screening
- Genetics
Background:
- Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most prevalent inherited enzymopathy globally.
- The fluorescent spot test (FST) is a traditional method for neonatal G6PD screening, but it has limitations.
- Quantitative assays, such as the CareStart Biosensor 1, are increasingly recommended for G6PD detection.
Purpose of the Study:
- To compare the diagnostic performance of the fluorescent spot test (FST) and the CareStart Biosensor 1 for detecting G6PD deficiency in neonates.
- To evaluate the ability of both methods to identify varying levels of G6PD activity.
Main Methods:
- A cross-sectional study involving 455 neonates.
- Analysis of cord blood using CareStart Biosensor 1 and dried cord blood spots using FST.
- Statistical analysis including sensitivity, specificity, and Cohen's kappa to assess agreement and performance.
Main Results:
- FST sensitivity decreased significantly at higher G6PD cut-off values (29.0% at 60% cut-off), while specificity remained high (100%).
- The prevalence of G6PD deficiency was 5.1% by FST versus 17.8% by Biosensor 1 (p < 0.001).
- FST misclassified individuals with intermediate G6PD levels as normal.
Conclusions:
- The FST misses a substantial number of neonates with intermediate G6PD deficiency.
- The CareStart Biosensor 1 identifies a higher prevalence of G6PD deficiency compared to FST.
- Accurate detection of G6PD deficiency is crucial to prevent oxidative stress-related complications.
Objectives:
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy worldwide. The fluorescent spot test (FST) is the conventional method for screening neonates for G6PD. However, it has limitations and quantitative assays such as the CareStart Biosensor 1 are being increasingly recommended. This study aimed to compare FST and CareStart Bioensor 1 in their ability to detect G6PD levels in neonates.
Methods:
This cross-sectional study involved 455 neonates between June and December 2020. Two milliliters of cord blood were analyzed with CareStart Biosensor 1 and dried cord blood spots with FST. Data was recorded and statistically analyzed. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the performance of FST at specific G6PD cut-off values; Cohen's kappa analysis assessed the agreement between the two methods.
Results:
The sensitivity of FST at 30% cut-off G6PD activity level was 91.0%, (95% CI: 57.0-100) and specificity of 97.0% (95% CI: 95.0-98.0). At 60% cut-off, the FST sensitivity sharply declined to 29.0% (95% CI: 19.0-40.0) with a specificity of 100% (95% CI: 98.0-100). The overall prevalence of G6PD deficiency was 5.1% as measured by FST and 17.8% by Biosensor 1 (p < 0.001).
Conclusions:
In this study, FST missed a significant proportion of cases of intermediate G6PD levels. FST also misclassified several G6PD intermediate individuals as normal, rendering them susceptible to oxidative stress. Biosensor 1 reported a significantly higher prevalence of G6PD deficiency.
