Age-related changes in red blood cell complement regulatory proteins and susceptibility to severe malaria.

Severe malaria-associated anemia and cerebral malaria are life-threatening complications of Plasmodium falciparum infection. Red blood cell (RBC) complement regulatory proteins (CRPs) have been implicated in the pathogenesis of both. We sought to determine whether there are age-related changes in the expression of CRPs that could explain the susceptibility to severe malaria-associated anemia in young children and the susceptibility to cerebral malaria in older children and adults.

Measurement of antibody levels against region II of the erythrocyte-binding antigen 175 of Plasmodium falciparum in an area of malaria holoendemicity in western Kenya.

Region II of the 175-kDa erythrocyte-binding antigen (EBA-175RII) of Plasmodium falciparum is functionally important in sialic acid-dependent erythrocyte invasion and is considered a prime target for an invasion-blocking vaccine. The objectives of this study were to (i) determine the prevalence of anti-EBA-175RII antibodies in a naturally exposed population, (ii) determine whether naturally acquired antibodies have a functional role by inhibiting binding of EBA-175RII to erythrocytes, and (iii) determine whether antibodies against EBA-175RII correlate with immunity to clinical malaria. We treated 301 lifelong residents of an area of malaria holoendemicity in western Kenya for malaria, monitored them during a high-transmission season, and identified 33 individuals who were asymptomatic despite parasitemia (clinically immune).