PROGNOSTIC-SIGNIFICANCE OF REDUCED RED-BLOOD-CELL DEFORMABILITY IN SEVERE FALCIPARUM MALARIA

Severe falciparum malaria is associated with microvascular obstruction resulting from sequestration of erythrocytes containing mature stages of the parasite, Since reduced red blood cell deformability (RBC-D) c an contribute to impaired microcirculatory dow, RBC-D was measured in 23 patients with severe falciparum malaria (seven of whom subsequently died), 30 patients with uncomplicated malaria, and 17 healthy control s. The RBC-D, measured by ektacytometry, was significantly reduced in severe malaria and was particularly low in all fatal cases. At a low s hear stress of 1.7 Pascal (Pa), a red blood cell elongation index less than 0.21 on admission to the hospital predicted fatal outcome with a sensitivity of 100% (confidence interval [CI] = 59-100%) and a specif icity of 88% (CI = 61-98%), The reduction in the RBC-D appeared to res ult mainly from changes in unparasitized erythrocytes. Reduced deforma bility of unparasitized red blood cells in severe malaria may contribu te to impaired microcirculatory how and a fatal outcome in severe falc iparum malaria.