Lily PolenchukUniversity of Alberta researchers have found that a portable blood test athletes use to measure their lactic acid levels can also quickly identify children critically-ill with malaria.
The study is a secondary analysis of clinical trials previously conducted by Michael Hawkes. He is an associate professor in the department of pediatrics. As well, he is a Former Stollery Science Lab Distinguished Researcher at the Stollery Children’s Hospital Foundation.
Hawkes did not design the initial clinical trials to examine the function of the lactic acid measuring tool. However, it was the secondary analysis done by Katie Mitran that led to crucial insights. Mitran holds a PhD in public health and is a third-year medical student at the U of A.
Children with high lactic acid levels and malaria upon hospital admission have a higher risk of mortality, according to a study authored by Mitran.
Cells produce lactic acid when breaking down glucose and carbohydrates to produce energy for body processes. This happens when cells need more oxygen than usual, such as during intense exercise.
“Lactic acid is a known marker of severe disease in a lot of [malaria] cases,” Mitran said.
According to the World Health Organization, parasite-infected mosquitoes spread malaria, a deadly blood-borne disease. Infants, pregnant women, children under five years old, and individuals with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) are at a higher risk of infection.
“Malaria killed 619,000 people [worldwide] in 2021, and the vast majority of those are children under the age of five in Sub-Saharan Africa,” Mitran said.
Cells produce lactic acid during illness because of oxygen deprivation, Mitran says
During illness, cells produce excess lactic acid when they’re not receiving enough oxygen from the blood.
“Lactic acid build-up is dangerous because it means the body is not receiving enough oxygen,” Mitran said. “Cells, which make up the body’s tissues and organs, try to adapt and compensate for the oxygen deprivation by producing more lactic acid than normal.”
Cells and tissues require lots of oxygen for metabolism to make energy. When the oxygen requirement is not met, cells will compensate. They switch the process of metabolism and produce lactic acid as a by-product.
The measuring tool is similar to a blood glucose monitoring device used by individuals with Type 2 diabetes. It only requires a small amount of blood from a finger prick to quickly determine lactic acid levels.
With malaria, “there’s a number of different reasons you get high levels of [lactic acid in blood],” Mitran said. “All [your] tissues can be deprived of oxygen if the parasites cause you to have severe anemia, which is a very common thing in malaria.”
The parasite can also damage the lung tissue, preventing oxygen from entering the bloodstream, Mitran said.
According to Mitran, “parasites can cause clogs in the small blood vessels,” leading to oxygen deprivation in nearby cells. Some parasites, which produce lactic acid, can reside in red blood cells, which deliver oxygen to tissues and organs. The parasite also affects the functioning of the liver and kidneys, which clear lactic acid from the bloodstream. Damage to these organs causes higher-than-normal lactic acid levels in the blood.
“Not only do you have this increased production of lactic acid, but then you also have this decreased clearance of lactic acid,” Mitran said. “The balance of that can be completely different in each patient. That’s still something they’re trying to figure out [with] malaria.”
“It’s potentially a useful tool to add to the evaluation of these patients,” Mitran says
Mitran said an advantage of the device is its consistency. The location or the amount of expertise of the person using the device does not impact the effectiveness.
“We showed whether it’s a highly trained clinician in a big referral hospital in Uganda or it’s a community health care worker in a rural setting using this device. Either way, the device performed the same,” Mitran said.
According to Mitran, the usefulness of testing lactate levels lies in the ability of the tool “[to] predict death in these children just as well as clinical evaluation.”
“When you combine those two factors together, it could predict death more accurately. So, it just showed that it’s potentially a useful tool to add to the evaluation of these patients.”
The team plans to see if using the tool to quickly identify children with a high risk of mortality will positively impact patient health outcomes.
