Differences in the frequency of cytokine-producing cells in antigenemic and nonantigenemic individuals with bancroftian filariasis.
Individuals with clinical manifestations of lymphatic filariasis may be currently infected or not. Twenty-five individuals from a Wuchereria bancrofti-endemic area of Brazil were classified as being asymptomatic microfilaremic individuals, antigenemic individuals with clinical filariasis, or nonantigenemic individuals with clinical filariasis. Intracellular cytokine staining of mitogen-stimulated peripheral blood mononuclear cells (PBMC) showed that the frequency of either gamma interferon (IFN-gamma)- or interleukin-4 (IL-4)-producing cells was higher in the nonantigenemic individuals with clinical filariasis than in the asymptomatic microfilaremic individuals (geometric means, 22.1 versus 10.7% [P = 0.02] and 2.9 versus 1.4% [P = 0.01], respectively). When the asymptomatic microfilaremic individuals and antigenemic individuals with clinical filariasis were grouped together to constitute all actively infected individuals, the frequency of IFN-gamma-producing cells was also lower than in the nonantigenemic individuals with clinical filariasis (P = 0.04). Likewise, the frequency of IL-4-producing cells in the actively infected individuals was also lower than in the nonantigenemic individuals with clinical filariasis (P = 0.02). No differences in the frequency of IFN-gamma-, IL-4-, or IL-5-producing cells in purified CD4 T lymphocytes were found among the groups. These findings suggest that the presence of antigenemia, which is an indicator of current active infection, is closely associated with the frequency of IFN-gamma- and IL-4-producing cells in lymphatic filariasis. The differences found in the frequency of cytokine-producing cells among the three groups appear to be due to a subset of cells other than CD4 T cells.
de Almeida
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AB
Division of Geographic Medicine, The University of Alabama at Birmingham, 35294-2170, USA. dflab@geomed.dom.uab.edu
Silva
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MC
Braga
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C
Freedman
D O
DO
D000293:Adolescent; D000328:Adult; D000818:Animals; D000947:Antigens, Helminth / Q000097:blood*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D005368:Filariasis / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D014958:Wuchereria bancrofti / Q000276:immunology*
D000947:Antigens, Helminth; D016207:Cytokines; D015847:Interleukin-4; D007371:Interferon-gamma