Repeatability and reproducibility of a handheld quantitative G6PD diagnostic

Area of Science:

• Medical Diagnostics
• Point-of-Care Testing
• Malaria Diagnostics

Background:

• Accurate diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency is crucial for radical cure regimens of Plasmodium vivax.
• Quantitative G6PD measurement is necessary for females due to their genetic make-up.
• SD Biosensor developed a handheld quantitative G6PD diagnostic device for point-of-care use.

Purpose of the Study:

• To evaluate the precision and reproducibility of the STANDARD G6PD test.
• To compare the device's performance against spectrophotometry.
• To determine the suitability of the device for routine clinical care.

Main Methods:

• Lyophilized G6PD controls (high, intermediate, low) were tested on multiple Biosensor devices.
• Devices were distributed to 10 laboratories for inter-laboratory reproducibility testing.
• Results were compared to spectrophotometry measurements.

Main Results:

• The STANDARD G6PD test demonstrated good repeatability and inter-laboratory reproducibility.
• High correlation was observed between Biosensor readings and spectrophotometry (rs = 0.859) when tested at a single site.
• Lower correlation (rs = 0.604) was found in inter-laboratory tests, with overlapping G6PD activity for low and intermediate controls.

Conclusions:

• The Biosensor device exhibits good precision but has limitations in discriminating between intermediate and low G6PD activities using lyophilized specimens.
• Further clinical studies are needed to validate the device's performance in real-world settings.
• The device's potential for routine use in G6PD deficiency diagnosis requires further assessment.