Dados do Trabalho

Título

Patterns of pulmonary and renal involvement in secondary dengue infection of BALB/cJ mice

Introdução

Dengue is a systemic viral infection, and epidemiological studies suggest that more severe cases occur mainly during secondary heterologous infection and associated with the dengue virus (DENV) serotypes -2 and -3. Studies on the pulmonary effects of DENV are scarce when considering other organs. However, even about the renal impairment, correlations to secondary infection and severity of the outcomes are still unknown.

Objetivo (s)

This study aimed to evaluate the impact of secondary infection in immunocompetent mice infected with non-neuroadapted clinical DENV strains on the morphological profile of the lungs and kidneys, which are shock organs.

Material e Métodos

To elucidate some of these points, two-month-old BALB/cJ mice were infected with 10^4 PFU of DENV-3 and, two months later, infected with 10^4 PFU of DENV-2, both by intravenous route. Five animals were analyzed by time of infection and the negative control group was MOCK-inoculated. After 3, 7, 10, 14 or 21 days after infection (DAI), mice were euthanized, the organs were collected and processed for analysis by bright field microscopy. Histomorphometry parameters were quantified in 30 fields per animal and included quantifying the thickness of alveolar septa in the lungs and counting the number of renal glomeruli per field as well as measuring their area.

Resultados e Conclusão

In the lungs, diffuse hemorrhage and consolidation of the lung parenchyma occurred at 7 and 10 DAI, times of infection in which the thickness of the alveolar reached the highest values compared to the negative control group. Endothelial activation, recruitment of inflammatory cells and edema were also observed. In the kidneys, alterations included: glomerular atrophy and hypertrophy, thickening of the visceral layer in the Bowman’s capsule, necrosis and desquamation of tubular cells, tubular retraction and presence of edema and inflammatory cells in the parenchyma. The intense glomerular atrophy surpassed the hypertrophy resulting in a reduction in the glomerular area from the 3 DAI to the 10 DAI compared to the negative control group. Both organs are related to multi-organ failure and, considering our findings, the level of morphological alterations observed throughout different times of infection might negatively affect other organs and impact the spectrum of outcomes in this secondary dengue infection murine model.

Palavras Chave

dengue; murine model