title: Gambiense human african trypanosomiasis and immunological memory: effect on phenotypic lymphocyte profiles and humoral immunity.
abstract: In mice, experimental infection with Trypanosoma brucei causes decreased bone marrow B-cell development, abolished splenic B-cell maturation and loss of antibody mediated protection including vaccine induced memory responses. Nothing is known about this phenomenon in human African trypanosomiasis (HAT), but if occurring, it would imply the need of revaccination of HAT patients after therapy and abolish hope for a HAT vaccine. The effect of gambiense HAT on peripheral blood memory T- and B-cells and on innate and vaccine induced antibody levels was examined. The percentage of memory B- and T-cells was quantified in peripheral blood, prospectively collected in DR Congo from 117 Trypanosoma brucei gambiense infected HAT patients before and six months after treatment and 117 controls at the same time points. Antibodies against carbohydrate antigens on red blood cells and against measles were quantified. Before treatment, significantly higher percentages of memory B-cells, mainly T-independent memory B-cells, were observed in HAT patients compared to controls (CD20+CD27+IgM+, 13.0% versus 2.0%, p<0.001). The percentage of memory T-cells, mainly early effector/memory T-cells, was higher in HAT (CD3+CD45RO+CD27+, 19.4% versus 16.7%, p = 0.003). After treatment, the percentage of memory T-cells normalized, the percentage of memory B-cells did not. The median anti-red blood cell carbohydrate IgM level was one titer lower in HAT patients than in controls (p<0.004), and partially normalized after treatment. Anti-measles antibody concentrations were lower in HAT patients than in controls (medians of 1500 versus 2250 mIU/ml, p = 0.02), and remained so after treatment, but were above the cut-off level assumed to provide protection in 94.8% of HAT patients, before and after treatment (versus 98.3% of controls, p = 0.3). Although functionality of the B-cells was not verified, the results suggest that immunity was conserved in T.b. gambiense infected HAT patients and that B-cell dysfunction might not be that severe as in mouse models.
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium; Institut de Recherche pour le Développement, UMR 177 IRD-CIRAD INTERTRYP, Montpellier, France.
authors.forename: Veerle
authors.initials: V
authors.lastname: Lejon
authors.affiliation: Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo.
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Mumba Ngoyi
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Kestens
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Boel
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Barbara
authors.initials: B
authors.lastname: Barbé
authors.affiliation: Programme Nationale de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of the Congo.
authors.forename: Victor
authors.initials: V
authors.lastname: Kande Betu
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: van Griensven
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bottieau
authors.affiliation: Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Muyembe Tamfum
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Jacobs
authors.affiliation: Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Büscher
mesh_terms: D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D056724:Immunity, Humoral / Q000276:immunology*; D007156:Immunologic Memory / Q000276:immunology*; D008297:Male; D010641:Phenotype; D014347:Trypanosoma brucei gambiense / Q000276:immunology; D014353:Trypanosomiasis, African / Q000097:blood / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan