Citologia do escarro induzido em asmáticos infectados pelo Schistosoma mansoni / Induced sputum cytology in asthmatics infected with Schistosoma mansoni

A infecção pelo Schistosoma mansoni inibe manifestação da asma. A avaliação do escarro induzido em pacientes infectados pelo parasita pode trazer informações importantes sobre a relação entre doenças alérgicas e parasitoses. Objetivo: Avaliar a celularidade do escarro em asmáticos em uma área endêmica em esquistossomose na Bahia. Métodos: Estudo randomizado, duplo cego, controlado com placebo, incluindo asmáticos infectados pelo S. mansoni e um grupo de asmáticos não infectados. Foi utilizada a celularidade do escarro induzido, em contagens sequenciais pré (D0) e pós-tratamento (D7, D60 e D90), para avaliar os efeitos do tratamento da parasitose com praziquantel sobre a asma. Resultados: Avaliados 22 indivíduos asmáticos infectados pelo S. mansoni e grupo controle adicional composto por oito asmáticos não infectados. O grupo que usou praziquantel não diferiu do grupo placebo quando comparada a celularidade do escarro. Houve aumento no número de eosinófilos nos D7, D60 e D90 no grupo placebo, quando comparados ao basal, e no D60 no grupo praziquantel. O número total de células aumentou em relação ao basal no D7 e no D90 para o grupo placebo, e no D90 para o grupo praziquantel. O grupo que usou praziquantel apresentou uma redução do volume expiratório forçado no 1º segundo (VEF1) no D7, D60 e D90. Não houve associação entre a eosinofilia e a gravidade da asma. Conclusão: No presente estudo não foi encontrada correlação entre os tipos celulares encontrados e a gravidade da asma, nem houve variação significativa do percentualde eosinófilos em resposta ao tratamento da esquistossomose...

Schistosoma mansoni infection inhibits asthma symptoms. Assessment of induced sputum in infected patients may shed light on the relationship between allergic diseases and parasite infections. Objective: To assess the cellularity of induced sputum in asthmatic patients living in an endemic area of schistosomiasis in the Brazilian state Bahia. Methods: This randomized, double blind, placebo-controlled study included asthmatic patients infected with S. mansoni and a group of non-infected asthmatics (controls). Cellularity of induced sputum was analyzed based on cell counts before (D0) and after treatment (D7, D60, and D90), to evaluate the effects of treatment with praziquantel on asthma. Results: A total of 22 asthmatics infected with S. mansoni and 8 controls were assessed. Induced sputum cellularity in the group treated with praziquantel did not differ from that of the group treated with placebo. However, compared to baseline counts, a higher number of eosinophils was found in the placebo group on D7, D60, and D90, and on D60 in the treatment group. Total cell counts increased from baseline to D7 and D90 in the placebo group, and from baseline to D90 in the treatment group. Moreover, the treatment group showed a reduction in forced expiratory volume in 1 second (FEV1) on D7, D60, and D90. There was no association between eosinophilia and asthma severity. Conclusion: In the present study, there was no correlation between asthma severity and the cell types found during cellularity assessment, nor was there an association between treatment of schistosomiasis and sputum eosinophilia...

Schistosoma mansoni antigen-driven interleukin-10 production in infected asthmatic individuals

Asthmatics infected with Schistosoma mansoni have a less severe course of asthma and an inhibition of the Th2 inflammatory response that seems to be mediated by interleukin (IL-10). The objective of this study was to evaluate the capacity of some S. mansoni antigens to stimulate IL-10 production in vitro by cells of asthmatic infected individuals. Peripheral bloods mononuclear cells were stimulated with the S. mansoni recombinant antigens Sm22.6, Sm14, P24, and PIII antigen. IL-10 was measured in the supernatants of cultures. As the recombinant antigens were cloned in Escherichia coli, we blocked contaminant endotoxin with polymyxin B added to the cultures. We demonstrated that all antigens used drove high production of IL-10 in S. mansoni infected individuals (n = 13, 408 ± 514 and 401 ± 383 pg/ml, 484 ± 245 pg/ml, 579 ± 468 pg/ml, respectively). In asthmatics infected with S. mansoni (n = 21) rP24 induced higher levels of IL-10 (565 ± 377 pg/ml) when compared to PIII, rSm14 and rSm22.6 (184 ± 209 pg/ml; 292 ± 243 pg/ml; 156 ± 247 pg/ml, respectively). Conclusion: the S. mansoni antigens evaluated in this study stimulated IL-10 production by cells from infected individuals and therefore they have the potential to be used as a modulator of the inflammatory response in asthma.

Aluminum hydroxide associated to Schistosoma mansoni 22.6 kDa protein abrogates partial protection against experimental infection but not alter interleukin-10 production

The need to develop a vaccine against schistosomiasis led several researches and our group to investigate proteins from Schistosoma mansoni as vaccine candidates. Sm22.6 is a protein from S. mansoni that shows high identity with Sj22.6 and Sh22.6 (79 and 91 percent, respectively). These proteins are associated with high levels of IgE and protection to reinfection. Previously, we have shown that Sm22.6 induced a partial protection of 34.5 percent when used together with Freund's adjuvant and produced a Th0 type of immune response with interferon-g and interleukin-4. In this work, mice were immunized with Sm22.6 alone or with aluminum hydroxide adjuvant and high levels of IgG, IgG1, and IgG2a were measured. Unfortunately, no protection was detected. Since IL-10 is a modulating cytokine in schistosomiasis, we also observed a high level of this molecule in splenocytes of vaccinated mice. In conclusion, we did not observe the adjuvant effect of aluminum hydroxide associated with rSm22.6 in protective immunity.