Estudo histopatológico do baço de camundongos Swiss Webster na fase aguda da esquistossomose mansoni e associada à desnutrição proteica

Abstract

Schistosomiasis mansoni is the second most prevalent parasitic disease in the world. Contagion occurs in contaminated fresh water bodies and with the presence of the intermediate host. The pathogenesis is established due to immunological reactions against Schistosoma mansoni eggs retained in different tissues. Chronic malnutrition is caused by the inadequate assimilation of nutrients and presents itself in different clinical forms of varying magnitude. It affects a large part of the world's population and is based on poverty. Nutritional deficiencies affect the spleen and the modulation of the immune response. Therefore, the present study aimed to perform a histopathological study of the spleen of schistosomal animals induced to protein malnutrition. For this purpose, 26 male Swiss Webster mice were used, equally divided into normoprotein and hypoprotein groups, where after weaning at 21 days, they were fed a diet containing 22% and 8% protein content, respectively. In the fourth week of the experiment, 7 animals from each group were infected with about 100 cercariae (BH strain) of S.mansoni, thus forming the groups: normoprotein control (CN), hypoprotein control (CH), normoprotein infected (IN) and hypoprotein infected (HI). The ponderal evolution and food consumption of the animals were followed during the whole experiment. Necropsy of the animals was performed at the ninth week of infection. After removal, the spleen was cleaved in two parts and submitted to routine histological processing for inclusion in paraffin blocks and preparation of histological slides, stained by hematoxylin and eosin (H&E). The spleen alterations were investigated by means of qualitative and quantitative histological analyses, with application of white pulp and capsule morphometry, stereology (D36 method) and megakaryocyte quantification. The histopathological analyses showed that the hypoprotein infected group presented a greater deposition of hemosiderin and bilirubin pigments, quantitative increase of trabeculae and megakaryocytes, although these presented a deficient synthesis, and intense organizational alterations of the splenic parenchyma. Therefore, the data presented suggest that protein deficiency exacerbates the disorganization of splenic tissue, common in schistosomiasis