Impact of autologous whole blood administration upon experimental mouse models of acute Trypanosoma cruzi infection

Predicting Blood Parasite Load and Influence of Expression of iNOS on the Effect Size of Clinical Laboratory Parameters in Acute Trypanosoma cruzi Infection With Different Inoculum Concentrations in C57BL/6 Mice

In Chagas disease, the initial responses of phagocyte-mediated innate immunity are strongly associated with the control of Trypanosoma cruzi and are mediated by various signaling pathways, including the inducible nitric oxide synthetase (iNOS) pathway. The clinical and laboratory manifestations of Chagas disease depend on the parasite–host relationship, i.e., the responsive capacity of the host immune system and the immunogenicity of the parasite. Here, we evaluated effect sizes in clinical and laboratory parameters mediated by acute infection with different concentrations of T. cruzi inoculum in mice immunosuppressed via iNOS pathway inactivation. Infection was induced in C57BL/6 wild-type and iNOS^-/- mice with the “Y” strain of T. cruzi at three inoculum concentrations (3 × 10², 3 × 10³, and 3 × 10⁴). Parasitemia and mortality in both mouse strains were monitored. Immunohistochemistry was performed to quantify amastigotes in cardiac tissues and cardiac musculature cells. Biochemical parameters, such as blood urea nitrogen, sodium, albumin, and globulin concentrations, among others, were measured, and cytokine concentrations were also measured. Effect sizes were determined by the eta squared formula. Compared with that in wild-type animals, mice with an absence of iNOS expression demonstrated a greater parasite load, with earlier infection and a delayed parasitemia peak. Inoculum concentration was positively related to death in the immunosuppressed subgroup. Nineteen parameters (hematological, biochemical, cytokine-related, and histopathological) in the immunocompetent subgroup and four in the immunosuppressed subgroup were associated with parasitemia. Parasitemia, biochemical parameters, and hematological parameters were found to be predictors in the knockout group. The impact of effect sizes on the markers evaluated based on T. cruzi inoculum concentration was notably high in the immunocompetent group (Cohen’s d = 88.50%; p <.001). These findings contribute to the understanding of physiopathogenic mechanisms underlying T. cruzi infection and also indicate the influence of the concentration of T. cruzi during infection and the immunosuppression through the iNOS pathway in clinical laboratory heterogeneity reported in acute Chagas disease.

Clinical effectiveness of autohemotherapy as an adjuvant in the control of gastrointestinal nematodes in naturally infected sheep

Abstract This study aimed to evaluate the effects of autohemotherapy as an adjuvant in the control of gastrointestinal nematodes in sheep. Four experimental groups were formed: G1, 10 animals receiving autologous venous blood; G2, 10 animals receiving autologous venous blood and vermifuge containing levamisole; G3, 10 animals receiving only vermifuge containing levamisole; and G4, 10 animals as the control group receiving no treatment. We performed fecal egg count (eggs per gram, EPG) of strongyles, larval culture, hemogram, leukogram, and serum protein dosage prior to the start of treatment (D0), and on days 14 (D14) and 42 (D42). There was a significant decrease in the EPG of the groups receiving levamisole (G2 and G3) from D14 to the end of the experimental period. At the end of the evaluations, the mean EPG of G2 and G3 was significantly lower than that of G1 and G4. The most common nematode genus was Haemonchus (88%), and the least common was Trichostrongylus (1%). The Fecal Egg Count Reduction Test (FECRT) of G2 and G3 on D14 were 98.1% and 97.9%, respectively, however, in G1, the FECRT was zero on the two days when evaluation took place. G1 and G2 showed a significant increase in monocyte counts on D14 and D42. There was a significant increase in hematocrit and hemoglobin values in G2 and G3, however, a significant increase in the absolute value of red blood cells was observed only in G2. Two doses of autohemotherapy at 21-day intervals, administered alone or as an adjuvant to levamisole, is ineffective in controlling gastrointestinal nematodes in naturally infected sheep.