Higher IL-10 levels are associated with less effective clearance of Plasmodium falciparum parasites.
The implications of high levels of the immune regulatory cytokine IL-10 in Plasmodium falciparum malaria are unclear. IL-10 may down-regulate pro-inflammatory responses and also exacerbate disease by inhibiting anti-parasitic immune functions. To study possible inhibiting effects on parasite clearance, IL-10 plasma levels were determined in 104 Tanzanian children, 1 to 4 years old, with acute uncomplicated P. falciparum malaria, and analysed for association with parasite densities during 3 days of anti-malarial treatment. Higher baseline IL-10 plasma levels were associated with statistically significantly higher parasite densities after 24, 48 and 72 h of treatment. These associations could not be explained by differences in initial parasitaemia, temperature, age, sex or type of treatment. Induction of high IL-10 production might be a direct or indirect mechanism whereby the parasite evades the immune response.
Malaria Research Unit, Division of Infectious Diseases, Department of Medicine, Karolinska Hospital, Karolinska Institutet, Stockholm, Sweden. ehugosson@hotmail.com
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Hugosson
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Montgomery
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Premji
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Troye-Blomberg
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Björkman
D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D016753:Interleukin-10 / Q000097:blood*; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000276:immunology* / Q000469:parasitology*; D018512:Parasitemia / Q000188:drug therapy / Q000276:immunology / Q000469:parasitology; D010963:Plasmodium falciparum / Q000276:immunology / Q000302:isolation & purification; D013636:Tanzania; D013997:Time Factors
D000962:Antimalarials; D016753:Interleukin-10