Malaria resistant with anemias

[Ella]

Hey guys,

Could someone explain the reasoning why only Sickle Cell anemia and G6PD deficiency patients are resistant to Malaria. Why aren't other intrinsic defect anemias patients such as hereditary spherocytosis and PK deficiency also resistant to malaria? Or are they??

Thanks.

[nafees ahmad]

in these condition cells have less oxygen inside so the parasite can not survive there

[student-2]

It's because the life span of the red blood cells is less then the needed time for the parasite to complete it's life cycle.
The oxygen tension in the RBC is the same it's just that in G6PD the RBC can't "handle" it and it undergoes an oxidative "explosion" if you will. That's why sickle trait and G6PD underwent "selection" in areas infested with malaria.

[bpoichan]

i agree with you guys...but i need to remind you that you are talking about the P.Falciparum...
for p. vivax it would have another mechanism... patients missing the Duffy antigen(mostly blacks) are resistant to P.vivax

[student-2]

bpoichan-
Can you elaborate????

[bpoichan]

sure
we have different types of Antigens stuck on our RBCs surface...
c, C, D, E,e...
now there is an Ag named the Duffy Ag ...and plasmodium VIVAX needs to anchor on it in order to enter a RBC....
Blacks are missing that Duffy Ag..and therefore are protected against Plasmodium VIVAX.