Alpha thalassemia, a blood disorder that is characterized by anemia caused by abnormally small red blood cells, may have the benefit of preventing malaria. Children with this disorder were found in a recent study to have a far greater chance of prevention for malaria than those without.
Hemoglobin is a protein in red blood cells which carries oxygen and is responsible for blood clotting. People suffering from anemia suffer a deficiency of hemoglobin in the blood, which can lead to hemorrhage, or excessive blood loss, in severe cases. Children with alpha thalassemia often experience a mild form of anemia. Malaria on the other hand can lead to much more sever anemia and hemorrhaging.
By having the small red blood cells and diminished hemoglobin levels, children with alpha thalassemia were found to be better protected against malaria, a disease which effects over 500 million people and kills upwards of 3 million, each year.
Dr. Karen Day, lead researcher for the study, says “We made the surprising finding that packaging your hemoglobin in smaller amounts in more cells is an advantage against malaria.”
The study was conducted of 800 children living in Papua, New Guinea, a region at high risk for malaria (Asia and Sub-Saharan Africa account for the majority of malaria cases worldwide). An astounding 68% of children in Papua suffer from alpha thalassemia. In severe malaria cases, often leading to fatalities, nearly one half of ones red blood cells can be lost. “For Children with mild alpha thalassemia tolerated this massive loss because they started out with 10 to 20 percent more red blood cells than unaffected children.”
These children, due to their condition, are more equipped to handle massive losses of blood. “these children do better because they end up with more hemoglobin overall when they have a malaria attack compared to normal children,” says Dr. Day.
These findings could have many uses, most importantly an understanding of how to deal with the most severe cases of malaria, and which individuals have the best chance of survival. It’s noted in the study that the majority of alpha thalassemia cases worldwide are of the mild nature, the form least likely to cause severe harm and most likely to protect against serious cases of malaria.
Source: Defeat Diabetes Foundation: Day, Karen. Klein, Lorinda. PLoS Medicine Press Release. March 2008.