Perfil Bioquímico, Hematológico e Imunológico de gerbils (Meriones unguiculatus) experimentalmente infectados por Giardia lamblia

• Ano de defesa: 2016
• Autor(a) principal: Frederico Ferreira Gil
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Giardia; Perfil bioquímico; Hematológico e imunológico; Cinética; Parasitologia
• Link de acesso: http://hdl.handle.net/1843/BUBD-AHRPUL

Giardia lamblia is a enteric parasite that infect human and animals, these parasite is distributed globally. The impact of clinical manifestations is observed in children resulting in deficits physical and cognitive development. Asymptomatic infections are frequent and usually auto-limited. The pathogenic mechanisms are poorly understood and available reports are often controversial. Basic questions such as haematological and biochemical changes from giardiasis they are not known. In this context, we pretended to know the evolution of the biochemical, hematological and immunological profile of gerbils experimentally infected with G. lamblia, searching for metabolic changes related to the development of the disease. The biochemical profile was evaluated by the serum dosage of some analytes. On the 21th day after infection (dai) glycemia increased, showing a peak at 28th (dai). Insulin followed the glucose behavior profile, suggesting that giardiasis determines a significant inflammatory process from the 3rd week of infection, resulting an increase of the insulin resistance. During infection, there was a progressive decrease in total proteins with the increase of albumin suggesting an increase of the dietary intake in the infection generating a state of anabolism with albumin elevation. This hypothesis is confirmed by the maintenance of the weight of the infected animals compared to uninfected. Cortisol behaved as expected. That is a significant increase after the 7th (dai) to the 14th (dai), when the animals were probably still inflamed with active infection by Giardia, falling again, but for values still significantly higher than the control. Serum calcium levels were significantly higher from the 14th (dai), thus remaining at 63rd (dai). The results of the alkaline phosphatase, AST and ALT analysis did not change with pathological significance, suggesting that hepatic functions would not be altered by infection. Cholesterol and triglycerides showed similar behavior, with a significant increase from the 21st (dai). These results contribute to the inflammation produced by giardiasis. Males and females presented differences in some analyzed parameters. However, behavior of the individual males group was like the behavior of both groups. In several biochemical variables analyzed it was observed a change from the 21st (dai), suggesting that giardiasis may be the trigger for these changes. All hematological variables were evaluated. Leukocytes did not present significant changes during infection. From the second week of infection it was observed the significant reduction in the number of red blood cells, hemoglobin concentration and hematocrit value confirming an anemia related to giardiasis. The reduction of serum iron level from the 3rd week of infection, although not significant, suggests the participation of iron in the anemia. However, the weight of the animals during the infection remained unchanged and the hematometric parameters began to return to baseline values after parasitological cure, without iron replacement. These results suggest that anemia in giardiasis relates more inflammatory and metabolic changes induced by the parasite that iron deficiency produced by mineral malabsorption. Although systemic inflammatory activation has been well established in this model, with the elevation of proinflammatory cytokines, which may have been activated macrophages and lymphocytes, it was not strong enough to lead to significant changes in the leukogram value. A constant but not significant decrease in the number of inflammatory infiltrate cells was observed in the lamina propria until D21 resurfaced in D28. Compared with the results of intraepithelial leukocyte counts, the results related to mucus production and crypt/villus ratio were within the expectation of an infection. Goblet cells and the relationship crypts / villi had a constant and significant increase during the study period. We evaluated the expression of cytokines IL-4, IL-6, IL-11, IL-12, IL-17, IFN- and TGF-. Although IL-4 showed a significant elevation signaling a Th2-type response, we did not detect changes in the IgE standart. Activation of the immune system with activation of lymphocytes to produce immunoglobulins seems relevant with the significant increase of serum IgA from the second week (D14), remaining high, but without statistical significance. IFN- and TGF- had a similar behavior, with a peak in D21, indicating that an anti-inflammatory action would be under way. There were significant alterations in IL-6 values from the second week of infection, remaining elevated throughout the documented infection period (D14 to D28), dropping to values close to that of the control at D35 when cure was established. IL-11 and IL-17 increased significantly in the 1st week (D7), with peak in the 2nd and 3rd weeks, respectively, returning to values close to the controls in the 5th week (D35). There were no significant changes in IL-12 values during the experiment, Although there has been a slight increase over time, with a peak in D28.