Sickle-cell hemoglobin could fight malaria

Sickle-cell hemoglobin may work to keep malaria in check, according to a new study.

Scientists used to believe that a mutation that deforms the oxygen-carrying protein in red blood cells prevented the malaria parasite from entering them. Researchers from the Instituto Gulbenkian de Ciência in Oeiras, Portugal, now suggest that an alternate mechanism might be at work, according to

The sickle-cell mutation leads to higher production of a protein known as heme oxygenase-1, which produces carbon monoxide gas. The study, published in the April 29 issue of Cell, showed that the gas helps reduce inflammation and kept alive mice whose brains had been infected with malaria.

The mutation primed the mice that had been genetically engineered to make human hemoglobin with the sickle-cell mutation to deal with the red blood cell shredding activities of the malaria parasite.

According to Miguel Soares, the study’s lead researcher, hemoglobin breaks down more easily in people with the sickle-cell mutation, releasing a toxic compound known as heme. When there is more heme in the blood stream, the body makes more of the heme oxygenase-1 enzyme, which leads to more carbon monoxide production, reports. The carbon monoxide attaches to the hemoglobin and prevents the heme from separating and causing more trouble.

“Before you get infected, sickle hemoglobin is releasing tiny amounts of heme. Your body looks at it and says, ‘This could be very dangerous, so I’m going to shut it down,” Soares said, according to

When the body is prepared for more heme, it is also prepared for the effects of the malaria parasite. The parasite is still able to infect the cell, but the host does not feel the effects, allowing the immune system to deal with the infection.

Malaria infected mice kept in a chamber with small amounts of carbon monoxide fared well, while those in a chamber with only regular air died, reports. Soares said that the finding suggests low doses of carbon monoxide could be used to treat malaria.