Antibody response to Salmonella typhi lw human Schistosomiasis mansoni

Abstract

Antibody response toActivation of the immune system has been demonstrated during acute schistosomiasis2 3 27 and, although modulation of both the cellular15" and humoral1819 immune responses occur later during the chronic phase of the disease, high levels of anti-Schistosom a m an son i antibodies are still detectable. However, the ability of infected individuals to mount an immune response to unrelated antigens has not yet been clearly established.It has been shown that some Schistosom ain fected individuals co-infected with salmonella p rod u ce less a n tib o d ies to both O and H antigens of this bacteria20 23, and antibodies present in their sera show an impaired ability to inhibit in vitro salmonella growth1'. However, serum from S chistosom a-infected hamsters can inhibit bacterial growth13. On the other hand, some human studies have indicated that schistosomiasis impairs the immune response to anti-salmonella vaccine5, while others do not seem to support this conclusion26.An altered ability of Schistosom a-infected individuals to produce antibodies to unrelated antigens may result in a con strain t to the elimination of some pathogens. For instance, it has been shown that antibodies help the clearance of salmonella from the blood stream11. Therefore, a deficient production of antibodies to salmonella in schistosomiasis may facilitate the development of the atypic form o f salm on ellosis w hich occu rs in Sch istosom a-infected individuals.This work aimed at evaluating the antibody response to S alm on ella typhi in Schistosom ain fected individuals before and after typhoid vaccine. MATERIAL AND METHODSThe rules put forw ard by the H elsinki Declaration for experiments in human subjects630 w e re s t r ic t ly f o llo w e d th r o u g h o u t th is investigation.Twenty six patients of both sexes, 13 to 43 y ears old (m ean ± SD = 24 ± 10), m ostly. Caucasians (75%) were studied. The diagnosis of schistosomiasis was established on clinical and parasitological grounds. Our study group :441-445, set-out, 1996. comprised 16 individuals with die hepatointestinal, and 10 with the hepatosplenic schistosomiasis, characterized according to the criteria defined by Prata21. Their clinical and nutritional status were satisfatory. Eggs of Schistosom a m an son i in faeces were quantified by the Kato-Katz method8. The control group comprised nine healthy individuals of both sexes, 20 to 50 years old (m ean ± SD = 29 ± 9), 70% being Caucasians. 441 M u n iz-Ju n qu eirã MI, Tavares-Neto J, P rata A, Tosta CE. A n tibody response toSalmonella typhi in h u m a n schistosom iasis m an son i. Revista d a S o cied a d e B rasileira d e M ed icin a T ropical 2 9The S alm on ella typhi vaccine, prepared with 10s formol-treated bacteria strain Ty2 by the Instituto Oswaldo Cruz, was intradermaliy administered in a single dose, as indicated by the manufacturer. Before vaccination and 30 days after serum antibodies to O and H a n tig e n s w e r e d e t e c t e d u s in g a W id al agglutination test29 provided by Laborclin. T...

Factors influencing phagocytosis of Salmonella typhimurium by macrophages in murine schistosomiasis

“…However, we also have previously shown in human schistosomiasis an impaired capacity to produce specific antibodies to Salmonella 16 . Therefore, the association in schistosomiasis of a reduced functional reserve of macrophages with the impaired production of specific antibodies 16 20 24 and the deficient Tlymphocyte function 17 appear to be insufficient to overcome the Salmonella infection as seems to be the case of chronic salmonellosis associated with schistosomiasis.…”

The effect of current Schistosoma mansoni infection on the immunogenicity of a candidate TB vaccine, MVA85A, in BCG-vaccinated adolescents: An open-label trial

“…There is substantial evidence of variability between populations in vaccine immunogenicity: notably, impaired responses to yellow fever vaccine were observed in Uganda, compared to Switzerland, in a study that found reduced vaccine virus replication and neutralising antibody production and persistence, in the context of elevated innate and adaptive immune response activation, among Ugandan volunteers [50]. There is evidence, for other vaccines, of differences (such as Th2 bias) in the response between people with and without schistosomiasis [7, 10], and of modulation of vaccine responses by other helminth species [8, 9]. Key factors in helminth-vaccine interactions are likely to include vaccine characteristics (live, replicating, protein or toxoid), prior exposure to environmental organisms or pathogens homologous to the vaccine, and the nature of the desired response (cellular or antibody).…”

“…In humans, the effects are less clear. Helminth infections can modulate vaccine-induced responses against tetanus [7], influenza [8], cholera [9], and Salmonella typhi [10]. T-helper (Th)1 responses are important for protective immunity against intracellular bacteria and viruses, while helminths characteristically induce Th2 [11] and immunoregulatory responses, both of which can down-regulate Th1 pathways [8].…”

Análisis epidemiológico de pacientes coinfectados con enfermedad de Chagas y cisticercosis

“…En algunos de esos casos ocurre un cuadro peculiar en que la progresión de la enfermedad sigue un desarrollo favorable al huésped (3)(4)(5)(6). Así, la agresión al tejido del huésped como, por ejemplo, la fibrosis y la inflamación, podría ocurrir de forma menos grave, permitiendo una mayor supervivencia, como se observó en nuestro material.…”