Clinical and immunological consequences of human T cell leukemia virus type-I and Schistosoma mansoni co-infection.
Human T cell leukemia virus type-I (HTLV-I) infection is associated with spontaneous T cell activation and uncontrolled lymphocyte proliferation. An exacerbated type-1 immune response with production of pro-inflammatory cytokines (interferon-gamma and tumor necrosis factor-alpha) is significantly higher in patients with myelopathy associated to HTLV-I than in HTLV-I asymptomatic carriers. In contrast with HTLV-I, a chronic Schistosoma mansoni infection is associated with a type-2 immune response with high levels of interleukin (IL-4, IL-5, and IL-10) and low levels of IFN-gamma. In this study, clinical and immunological consequences of the HTLV-I and S. mansoni infection were evaluated. The immune response in patients with schistosomiasis co-infected with HTLV-I showed low levels of IL-5 (p < 0.05) in peripheral blood mononuclear cells cultures stimulated with S. mansoni antigen (SWAP) and decreased SWAP-specific IgE levels when compared with patients with only schistosomiasis (p < 0.05). Liver fibrosis was mild in all HTLV-I co-infected patients. Immunological response was also compared in individuals who had only HTLV-I infection with those who were co-infected with HTLV-I and helminths (S. mansoni and Strongyloides stercoralis). In patients HTLV-I positive co-infected with helminths the IFN-gamma levels were lower than in individuals who had only HTLV-I. Moreover, there were fewer cells expressing IFN-gamma and more cells expressing IL-10 in individuals co-infected with HTLV-I and helminths. These dates indicate that HTLV-I infection decrease type 2-response and IgE synthesis and are inversely associated with the development of liver fibrosis. Moreover, helminths may protect HTLV-I infected patients to produce large quantities of pro-inflammatory cytokines such as IFN-gamma.
Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, Rua João das Botas, s/n, 40110-160 Salvador, BA, Brazil.
Silvane Braga
SB
Santos
Aurélia Fonseca
AF
Porto
André Luiz
AL
Muniz
Amélia Ribeiro de
AR
Jesus
Edgar M
EM
Carvalho
D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology; D016022:Case-Control Studies; D002908:Chronic Disease; D016207:Cytokines / Q000096:biosynthesis*; D015490:HTLV-I Infections / Q000150:complications* / Q000276:immunology; D015368:Human T-lymphotropic virus 1 / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008103:Liver Cirrhosis / Q000276:immunology / Q000821:virology*; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000150:complications* / Q000276:immunology; D018709:Statistics, Nonparametric
D000947:Antigens, Helminth; D016207:Cytokines