Sickle Cell Trait Protects Against Plasmodium falciparum Infection
"Sickle Cell Trait Protects Against Plasmodium falciparum Infection" addresses whether sickle cell trait is effective in protecting carrier children from asymptomatic malaria caused by P. falciparuminstead of only symptomatic malaria. If the carrier is protected from asymptomatic malaria, then sickle cell trait is doing more than decreasing the severity of symptoms and is actually affecting the parasite. The study was carried out in a village in Mali over two years and included 621 children—450 of whom were positive for P. falciparum at the beginning of the study and 171 were negative. Children with HbAS had lower concentration of P. falciparum per μL and had malaria less often. Additionally, children initially negative for P. falciparum with HbAS remained negative longer than those with HbAA, and children initially positive for P. falciparum with HbAS returned to negative faster than those with HbAA. The results of this study indicate sickle cell trait does protect the carrier from asymptomatic malaria as well as symptomatic malaria.[8]
Mechanisms Behind Malarial Protection from Sickle Cell Trait
It is widely accepted that sickle cell trait protects the carrier from malaria (both symptomatic and asymptomatic), yet all of the mechanisms are still not fully understood. Some mechanisms, including smaller numbers of P. falciparum being able to infect sickled cells due to their shapes and increased rates of phagocytosis of infected sickled cells, have been accepted and supported for many years. Others, such as microRNAs entering the parasite and tampering with its genome, have only been considered more recently but have very strong supporting evidence.[7] These recent discoveries seem to be very promising for further attempts to curve rates of infection for all forms of malaria without relying on the presence of sickle cell trait.