Anti-Anopheles darlingi saliva antibodies as marker of Plasmodium vivax infection and clinical immunity in the Brazilian Amazon

• Autor(a) principal: Andrade, Bruno B.
• Data de Publicação: 2009
• Outros Autores: Rocha, Bruno Coelho, Reis-Filho, Antonio, Camargo, Luis Marcelo Aranha, Tadei, Wanderli Pedro, Moreira, Luciano Andrade, Barral, Aldina Maria Prado, Barral-Netto, M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional do INPA
• Texto Completo: https://repositorio.inpa.gov.br/handle/1/16305
• topic: Darlingi Saliva Gland Sonicate Antibody; Gamma Interferon; Interleukin-10; Protozoon Antibody; Unclassified Drug; Antibody; Biological Marker; Gamma Interferon; Insect Proteins; Interleukin-10; Adult; Antibody Blood Level; Antibody Titer; Blood Sampling; Brasil; Concentration (parameters); Control Group; Controlled Study; Cytokine Production; Disease Severity; Female; Human; Humoral Immunity; Immunity; Major Clinical Study; Microscopy; Parasitemia; Plasmodium Vivax; Plasmodium Vivax Malaria; Polymerase Chain Reaction; Screening; Animals; Anopheles; Blood; Immunology; Middle Aged; Plasmodium Vivax Malaria; Prediction And Forecasting; Saliva; Adult; Animal; Anopheles; Antibodies; Biological Markers; Brasil; Female; Humans; Insect Proteins; Interferon-gamma; Interleukin-10; Malaria, Vivax; Middle Aged; Predictive Value Of Tests; Saliva; Young Adult

Background. Despite governmental and private efforts on providing malaria control, this disease continues to be a major health threat. Thus, innovative strategies are needed to reduce disease burden. The malaria vectors, through the injection of saliva into the host skin, play important role on disease transmission and may influence malaria morbidity. This study describes the humoral immune response against Anopheles (An.) darlingi saliva in volunteers from the Brazilian Amazon and addresses the association between levels of specific antibodies and clinical presentation of Plasmodium (P.) vivax infection. Methods. Adult volunteers from communities in the Rondônia State, Brazil, were screened in order to assess the presence of P. vivax infection by light microscopy and nested PCR. Non-infected volunteers and individuals with symptomatic or symptomless infection were randomly selected and plasma collected. An. darlingi salivary gland sonicates (SGS) were prepared and used to measure anti-saliva antibody levels. Plasma interleukin (IL)-10 and interferon (IFN)- levels were also estimated and correlated to anti-SGS levels. Results. Individuals infected with P. vivax presented higher levels of anti-SGS than non-infected individuals and antibody levels could discriminate infection. Furthermore, anti-saliva antibody measurement was also useful to distinguish asymptomatic infection from non-infection, with a high likelihood ratio. Interestingly, individuals with asymptomatic parasitaemia presented higher titers of anti-SGS and lower IFN-/IL-10 ratio than symptomatic ones. In P. vivax-infected asymptomatic individuals, the IFN-/IL-10 ratio was inversely correlated to anti-SGS titers, although not for while in symptomatic volunteers. Conclusion. The estimation of anti-An. darlingi antibody levels can indicate the probable P. vivax infection status and also could serve as a marker of disease severity in this region of Brazilian Amazon. © 2009 Andrade et al; licensee BioMed Central Ltd.