Histomorfometria de granulomas pulmonares nas fases aguda e crônica durante a infecção murina por Schistosoma mansoni e análise das correlações com eosinofilia sanguínea, presença de ovos e granulomas hepáticos

Abstract

Schistosomiasis is a debilitating disease that can affect various tissues of the human body. The immune response starts with a predominance of Th1 cells and gradually changes to the Th2 profile from oviposition, for the formation and maturation of granulomas. While the lung is one of organs most susceptible organs, it is vulnerable to the parasite in both the acute and chronic phases. Within this context, the objective of this work is to describe the histopathological and histomorphometric alterations in the lung of mice infected with Schistosoma mansoni, as well as to investigate correlations with the presence of eosinophils in the blood, parasite eggs and hepatic granulomas. Initially, male Swiss mice were percutaneously infected with 50 cercariae of Schistosoma mansoni and euthanized after 60 (INF60) and 90 days after infection (INF90). At each time point, there was also euthanasia in a group composed of uninfected animals. Blood was obtained by puncture through the orbital plexus for evaluation of leukocytes. The rectum and liver were removed respectively to prove the infection and histomorphometric comparison. While the lungs were removed for histopathological and histomorphometric analysis. The data showed that within sixty days of infection, there was local and systemic eosinophilia (p<0.0001), associated with a tissue inflammatory process, with pre-granulomatous formation and a predominance of granulocytes in the lung tissue, a period in which there were already several mature granulomas in the liver. Ninety days after the infection, the appearance of pulmonary granulomas and a decrease in blood eosinophilia were observed, which was correlated with the number of eggs in the feces (r= -0.8 and p = 0.01) and the number of granulomas in the liver (r= -0.8 and p = 0.01). The data confirm the importance of the participation of eosinophils in the process, being able to discriminate evolutionary moments and the intensity of the disease until the onset of chronicity, as well as exposing a delay in lung disease compared to liver disease. The data presented in this study confirm the need to observe pulmonary schistosomiasis as an individualized disease in its diagnosis, classification, and management.