Methods for the field evaluation of quantitative G6PD diagnostics: a review

Area of Science:

• Clinical diagnostics
• Parasitology
• Pharmacogenomics

Background:

• Glucose-6-phosphate dehydrogenase (G6PD) deficiency poses a risk for hemolysis with 8-aminoquinoline antimalarials.
• Primaquine is essential for Plasmodium vivax radical cure, but requires G6PD testing.
• Tafenoquine, a new antimalarial, necessitates quantitative G6PD point-of-care (PoC) tests for safe administration.

Purpose of the Study:

• To outline technical details for the field evaluation of novel quantitative G6PD diagnostics.
• To ensure the development and validation of reliable G6PD PoC tests for clinical use.
• To guide the implementation of G6PD PoC tests for safe antimalarial drug administration.

Main Methods:

• Field evaluation involves comparing paired samples tested with novel PoC assays and gold-standard UV spectrophotometry.
• Sample handling recommendations include using capillary or venous blood, storing at 4°C, and testing within 4 days.
• Statistical analysis includes scatter plots, Bland-Altman plots, histograms, and receiver operating characteristic (ROC) analysis.

Main Results:

• Standardized field evaluation protocols are essential for validating new G6PD PoC tests.
• Proper sample collection, storage, and timely testing are critical for preserving enzyme activity.
• Quantitative G6PD measurements enable accurate patient categorization and risk assessment for antimalarial treatment.

Conclusions:

• Validated G6PD PoC tests are critical for the safe and effective use of 8-aminoquinoline antimalarials, particularly for Plasmodium vivax.
• Standardized field evaluation methodologies will facilitate the market entry and clinical adoption of new G6PD diagnostics.
• Accurate G6PD activity measurement ensures patient safety by preventing drug-induced hemolysis.