Institut National de la Sante et de la Recherche Medicale (INSERM) Unite 13 et Institut de Medecine et d'Epidemiologie Africaines (IMEA), Antenne Institut Francais en Recherche Scientifique pour le Developpement en Cooperation (ORSTOM) et Service des Laboratoires, Organisation de Coordination pour la Lutte Contre les Endemies en Afrique Centrale (OCEAC), Service de Pharmacologie et d'Immunologie, Commissariat a l'Energie Atomique, Unite de Physiopathologie de l'Infection, Institut Pasteur, Department of Medical Parasitology, University of Nijmegen, Paris, France
To investigate the mechanisms underlying the increased susceptibility to malaria in pregnant women, we determined the level of malaria-specific immunity in primigravidae. Humoral and cellular in vitro responses to unpurified (a crude schizont extract and a gametocyte preparation) and purified (affinity-purified Pf155/ring-infected erythrocyte surface antigen [RESA]) Plasmodium falciparum proteins, an immunodominant 45/47-kilodalton antigen from Mycobacterium bovis, and leucoagglutinin were compared between 52 primigravidae and 52 nonpregnant women from a semirural area of Cameroon. In vitro cellular responses were investigated in terms of lymphocyte proliferation, as well as production of interleukin-2 (IL-2), interferon-gamma (IFN-γ), and IL-4. Cells from primigravidae exhibited a reduced proliferative response to schizont and gametocyte antigens, as well as to the M. bovis antigen. Conversely, the IL-2 response to Pf155/RESA was reduced. Interleukin-4 and IFN-γ production did not appear to be affected in primigravidae. Antibody levels were also similar between pregnant and nonpregnant women. Our results underline the importance of examining several parameters of T cell activation with different types of antigens for a correct evaluation of the ability of lymphocytes to respond to malaria.