Cytokine profiling in immigrants with clinical malaria after extended periods of interrupted exposure to Plasmodium falciparum

PLoS One. 2013 Aug 14;8(8):e73360. doi: 10.1371/journal.pone.0073360. eCollection 2013.

Abstract

Immunity to malaria is believed to wane with time in the absence of exposure to Plasmodium falciparum infection, but immunoepidemiological data on longevity of immunity remain controversial. We quantified serum cytokines and chemokines by suspension array technology as potential biomarkers for durability of immunity in immigrants with clinical malaria after years without parasite exposure. These were compared to serum/plasma profiles in naïve adults (travelers) and semi-immune adults under continuous exposure, with malaria, along with immigrant and traveler patients without malaria. Immigrants had higher levels of IL-2, IL-5 and IL-8 compared to semi-immune adults with malaria (P≤0.0200). Time since immigration correlated with increased IL-2 (rho=0.2738P=0.0495) and IFN-γ (rho=0.3044P=0.0282). However, immigrants did not show as high IFN-γ concentrations as travelers during a first malaria episode (P<0.0001). Immigrants and travelers with malaria had higher levels of IFN-γ, IL-6, and IL-10 (P<0.0100) than patients with other diseases, and IL-8 and IL-1β were elevated in immigrants with malaria (P<0.0500). Therefore, malaria patients had a characteristic strong pro-inflammatory/Th1 signature. Upon loss of exposure, control of pro-inflammatory responses and tolerance to P. falciparum appeared to be reduced. Understanding the mechanisms to maintain non-pathogenic effector responses is important to develop new malaria control strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biomarkers / blood
  • Chemokines / blood
  • Cytokines / blood*
  • Emigrants and Immigrants / statistics & numerical data*
  • Endemic Diseases
  • Environmental Exposure / statistics & numerical data*
  • Female
  • Humans
  • Malaria, Falciparum / blood*
  • Malaria, Falciparum / diagnosis
  • Malaria, Falciparum / epidemiology
  • Malaria, Falciparum / immunology*
  • Male
  • Plasmodium falciparum / immunology
  • Plasmodium falciparum / physiology*
  • Prognosis

Substances

  • Biomarkers
  • Chemokines
  • Cytokines

Grants and funding

The study received financial support from the Ministerio de Ciencia e Innovación (SAF2008-00743, salary support RYC-2008-02631 to C.D.); the Agència de Gestió d’Ajuts Universitaris i de Recerca (2009SGR934, 2009SGR385); the Instituto de Salud Carlos III (PI050275, PS0901113, salary support CD10/00156 to G.M., CP-4/00220 to A.M.), and the Fundación Ramón Areces. The Centro de Investigação em Saúde de Manhiça receives core support from the Spanish Agency for International Cooperation and Development (AECID). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.