The eosinophilic response and haematological recovery after treatment for Plasmodium falciparum malaria

Abstract
SummaryTo examine a possible relationship between the immune response and haematological recovery after acute falciparum malaria, we followed peripheral blood eosinophil counts and haemoglobin concentrations for 4 weeks after starting effective treatment in 70 adult Thai patients. Eosinophils are induced by Th‐2 cytokines as well as other stimuli. Eosinophil counts were elevated in only 8 (11%) of the subjects at presentation, but were increased in 65 (93%) by day 7. Eosinophil counts then decreased markedly by day 14, followed by a second increase until day 28. A significant positive correlation was found between peak eosinophil counts on day 7 and the haemoglobin concentration on day 28, both in 16 subjects without stool parasites (= 0.65, = 0.006) and in 54 patients with stool parasites (= 0.32; = 0.0019). These results suggest that a robust eosinophilic response shortly after completing antimalarial therapy predicts a good recovery from malaria‐associated anaemia.