People with deficiencies in the metabolic enzyme glucose-6-phosphate dehydrogenase (G6PD) are at high risk for severe anemia and its consequences if treated with certain anti-malaria drugs, the 8- aminoquinolines. These medications are used to kill the Plasmodium vivax (P. vivax) parasite, which causes about half of malaria cases outside sub-Saharan Africa. More than 400 million people worldwide have G6PD deficiencies, which are especially common in malaria-endemic regions. Best clinical practice requires testing for G6PD deficiency before administering the drugs, but tests that meet technical requirements and are appropriate for use in low-resource settings are not currently available. PATH aims to accelerate the development and introduction of a point-of-care (POC) G6PD diagnostic test to support the safe use of 8-aminoquinoline-based drugs in areas with P. vivax malaria.

Test developers will need to evaluate their technologies throughout the product development process with blood samples expressing different G6PD levels that have been characterized by gold standard G6PD assays. However, collecting, processing, and maintaining a supply of samples would be costly and timeconsuming for individual companies. Obtaining specimens with a range of G6PD activities, from severely deficient to normal, is challenging because of the low prevalence of mutations in non-malaria-endemic regions, where most test development occurs.

To address this need, PATH has established a repository of cryopreserved blood samples highly characterized for G6PD activity. The cryopreservation technique keeps red blood cells from rupturing and prevents loss of enzyme activity, so that cells can be analyzed weeks to months after blood collection. The specimens, recruited on a continuous basis, will be used at PATH to evaluate performance of the technologies as they progress through product development stages. Panels of specimens also are available to all product developers, ensuring global access to the resource and facilitating an accelerated G6PD diagnostic product pipeline.