The discovery of pfcrt's "central role" in malarial drug resistance could "help in the development of new therapeutic strategies that are effective against chloroquine-resistant parasites," said David Fidock of Albert Einstein College of Medicine, one of the lead authors of the paper.
Nearly three million people, mostly children, die from malaria each year. Chloroquine is one of the most affordable and widely used antimalarial drugs available, but chloroquine-resistant malaria has become an increasingly serious problem in the developing world, with death rates rising as a consequence.
The experiments conducted by Fidock and colleagues suggest that previously unknown mutations in the pfrct gene are associated with Plasmodium falciparum's resistance to halofantrine and amantadine. The two drugs are used to treat mild to moderate cases of chloroquine-resistant malaria.
Fidock said pfcrt's role in halofantrine and amantadine resistance was "a big surprise actually, for both drugs. We thought initially that pfcrt was only critical for chloroquine."
The researchers uncovered the new pfcrt mutations after gradually creating strains of malaria resistant to halofantrine and amantadine treatment. As resistance to these two drugs increased, however, the parasites lost their resistance to chloroquine.
This unusual pattern--gaining resistance to one drug while simultaneously losing resistance to another--may shed light on the exact role that pfcrt plays in resistance, according to Fidock and colleagues.