Potential Hemoglobin A/F role in clinical Malaria

The Malarial parasite resides in the host RBC during its erythrocytic cycle. Plasmodium meets its entire nutritional requirement from RBC. It scavenges the hemoglobin of RBCs to meet its amino acid requirement. The host hemoglobin is made of different chains and it is dependent on age. Hemoglobin F (HbF), which has two-alpha and two gamma chain persists in children upto six years, and hemoglobin A (HbA) made of two alpha and two beta chains dominates. Therefore, it is of interest to compare the compositional features of HbA with HbF. Isoleucine is present in hemoglobin of children (gamma chain of HbF) while it is absent in adult hemoglobin (HbA). The presence of Isoleucine (I) makes HbF ideally suitable for the growth of parasite, as it does not have to depend upon the exogenous supply of the isoleucine, which might be responsible for making children more vulnerable to malaria as compared to adults.