Complexity doesn’t slow the PATH laboratory team down. It inspires them.
So when a scientific conundrum threatened to hinder malaria treatment worldwide, they got to work. “Laboratory puzzles are what we do, and this one caught our interest,” says Sampa Pal, one of the lead scientists on the team. “We thought: ‘We have the tools to crack this and help stamp out malaria. Let’s take a look.’”
It’s in the genes
The puzzle? A hereditary condition called G6PD (glucose-6-phosphate dehydrogenase) deficiency that complicates treatment for the parasite that most often causes malaria, Plasmodium vivax malaria or P. vivax.
In some parts of the world, an estimated 20 percent of the population carries the trait. For these people, treatment with drugs against P. vivax malaria can be dangerous—causing a potentially fatal condition called hemolytic anemia, in which the body destroys red blood cells.
If people with G6PD deficiency are diagnosed ahead of time, health workers can take steps to prevent the condition and watch for symptoms of anemia. But existing tests—especially those designed to be used in the field or right in the clinic (what health workers call “rapid” or “point-of-care” tests)—have limitations. Many are too expensive, too slow, or require laboratory support that isn’t available in remote areas. In addition, rapid tests currently on the market often fail to detect the condition among women because of the way the G6PD gene is carried on the chromosome. There was a clear need for a more suitable diagnostic to test for G6PD.
Minding the gap
Sampa’s team, which also includes researchers Maria Kahn and Nicole LaRue, knew they could help.
“First, we searched to see whether any existing rapid tests for G6PD deficiency could be used in low-resource settings where malaria occurs,” explains Sampa. “Our goal was to test those options to see how well they worked, and identify where the gaps were.” That information would then go to the diagnostic developers PATH partners with who could use it to create or adjust promising new prototypes aimed at accelerating the elimination of malaria.
It seemed straightforward—but first, there was another hurdle the team would need to address.
A “treasure chest” full of liquid nitrogen
To develop a new diagnostic, scientists and developers need blood samples containing a diverse range of whatever the test is meant to find (in this case, samples that contain known levels of G6PD activity). But G6PD levels fade quickly in blood specimens, especially when samples are preserved for storage and transport.
To solve the problem, Maria and Nicole applied an existing technique for preserving blood samples so they could be stored, categorized by levels of G6PD activity, and used to test new prototypes. “With this approach,” notes Maria, “levels of G6PD activity remain unchanged in a sample so that it can still be used—the day it’s collected or three weeks later.”
Using this technique, the team built a first-of-its-kind specimen bank (or repository) of blood samples with G6PD activity, stored in liquid nitrogen, and made it available to researchers and developers worldwide.
These samples can be used by PATH and our partners to develop diagnostics that will help combat malaria in areas where G6PD deficiency is common while supporting research into other applications. As Maria describes it, “The specimen bank is like a treasure chest that will save time and money for G6PD test developers and donors. It may ultimately help get these tests even faster to communities that need them.”
Meanwhile, a new, better test
The lab team evaluated the G6PD test prototypes and shared their findings with PATH’s diagnostic development partners. If successful, these diagnostics could be more accurate, faster, more affordable, and better at detecting G6PD among women—helping countries worldwide put malaria on the run.
“With the specimen bank and new prototypes, we’re seeing our efforts come to fruition,” says Sampa. “Whether the science behind it is complex or not, our ultimate goal is clear: to eliminate malaria.”