Immunostimulation as Adjuvant for the Chemotherapy of Experimental Schistosomiasis

Abstract

Immunosuppressed animals respond poorly to schistosomal chemotherapy and a proper response can be restored by the administration of immune serum. Present study attempts to search whether immunological stimulation would increase drug effectiveness. Swiss mice infected with 50 S. mansoni cercariae were later treated with complete Freund's adjuvant. Treatment with oxamniquine was made with 100 mg/kg.b.w., 25 mg/kg.b.w. and 50 mg/kg.b.w., the last two doses representing a fourth and a half of the recommended curative dose. Appropriate controls for the drug, the adjuvant and the infection were also studied. The serum-level of anti-S. mansoni antibodies (ELISA) and recovery of worms by perfusion of the portal vein system were the evaluated parameters. Statistical analysis of the results failed to reveal significant differences in worm recovery between adjuvant-stimulated animals treated with oxamniquine and any of the treated controls receiving the same amount of the drug. Although total lack of immunity interferes with curative treatment the usual immune response seems to be sufficient to allow for curative drug action in schistosomiasis and thus apparently does not need to be artificially stimulated.

Biochemical and Immunologic Predictors of Efficacy of Treatment or Reinfection Risk for Schistosoma Mansoni

“…The immune response is an important component of the mechanism of action for praziquantel. [26][27][28][29] Immunosuppression is associated with decreased efficacy of oxamniquine in experimental mice, but reconstitution of these animals with immune serum fully restores effectiveness. While much has been written about the deleterious effect of immune responses to LDL-cholesterol, 30 the pro-inflammatory properties of this form of lipid might be responsible for the effects we see here by altering the immune response to interluminal tissues including those of the parasite.…”

Chemotherapeutic effects on larval stages of Schistosoma mansoni during infection and re-infection of mice

“…The schistosomicides administered cause focal areas of damage to the worm tegument 12 18 , exposing target antigens to host antibodies, which ultimately provoke the worm death 3 9 17 . Unfortunately, the role played by the immune system cannot be enhanced by means of artificial antigenic stimulation 19 . There are few and contradictory experimental data concerning the participation of the immune response during the drug killing of immature schistosomes.…”

Análise Da Esquistossomose Na Região Nordeste De 2020 a 2023: Diagnóstico, Terapêutica E Considerações Clínicas

“…Caramujos de água doce do gênero Biomphalaria funcionam como hospedeiros intermediários, enquanto os seres humanos assumem o papel de hospedeiros definitivos. Essa enfermidade é amplamente disseminada em escala global, apresentando-se como um desafio expressivo para a saúde pública, especialmente em nações em desenvolvimento (Lira;Campos;Silva, 2019;Sobrinho et al, 2020).…”

“…O controle da doença nessas localidades ainda não foi plenamente alcançado Brazilian Journal of Implantology and Health Sciences Volume 6, Issue 2 ( 2024), Page 691-711. (Silva;Sá, 2019;Souza;Grala;Villela, 2021).…”

“…Tais fatores contribuem para o contato direto das populações residentes em áreas endêmicas com águas contaminadas por caramujos, que atuam como hospedeiros intermediários do parasita (Araújo et al, 2021). A partir desse período, as ações de controle e vigilância da doença passaram a ser realizadas pelos municípios, desempenhando papéis cruciais na execução das principais estratégias de combate à esquistossomose (Costa et al, 2017;Silva;Wanderley, 2022).…”