Research: Malaria and sickle cell trait
31 May 2005
The blood cell abnormality sickle cell trait protects against malaria because of its effect on the immune response.
While it has been known for some time that sickle cell trait offers protection against malaria, the mechanisms have never been clear.
Now, a study, led by Dr Tom Williams of the Kenya Medical Research Institute/Wellcome Trust Research Programme in Kilifi, Kenya has discovered an unexpected link with immunity. Children with sickle cell trait have shown enhanced immunity to the malaria parasite, with the level of immunity increasing with age.
Sickle cell trait occurs when someone inherits a normal haemoglobin gene from one parent and a sickle haemoglobin gene from the other. While children with sickle cell trait do not usually display symptoms, children who inherit a double dose of the sickle gene suffer from sickle cell disease, which can cause chronic ill health and early death.
Further research will be needed to find out why the trait leads to increasing levels of immunity. One possibility, suggested by Dr Williams, is that a malaria infection persists in the body for longer, so allowing the immune system time to build up a better defence.
See also
- Sickle cell trait offers malaria protection to children (Press release: 30 May 2005)