Response activity of alveolar macrophages in pulmonary dysfunction caused by Leptospira infection

Abstract

Leptopspirosis is a syndrome with different clinical manifestations including the most severe and often fatal forms of pulmonary disease of unknown etiology. Pulmonary injury during the inflammatory process has been associated with the excessive number of alveolar macrophages (AMs) and polymorphonuclear leukocytes stimulated in the lungs and with the production of reactive oxygen and nitrogen intermediates and other inflammatory mediators. The aim of the present work was to evaluate the cellular immune response of AMs or inflammatory cells of hamsters during leptospirosis. The activity of AMs was determined by measuring nitric oxide (NO) and protein production as well as inflammatory cell infiltration in bronchoalveolar lavage (BAL) fluid. Pulmonary activity during infection was monitored by measuring pH, pressure of oxygen (PaO2), and pressure of carbon dioxide (PaCO2) in blood samples. Cellular immune response and its role in the genesis of leptospirosis have been incriminated as the main causes of tissue and pulmonary injuries, which consequently lead to the pulmonary dysfunction in severe cases of leptospirosis. The present results show a low production of NO in both supernatant of alveolar macrophage culture and BAL. In the latter, protein production was high and constant, especially during acute infection. Total and differential cell count values were 2.5X10(6) on day 4; 7.3X10(6) on day 21; and 2.3X10(6) on day 28 after infection, with lymphocytes (84.04%) predominating over neutrophils (11.88%) and monocytes (4.07%). Arterial blood gas analysis showed pulmonary compromising along with the infectious process, as observed in parameter values (mean±SD) evidenced in the infected versus control group: PaO2 (60.47mmHg±8.7 vs. 90.09mmHg±9.18), PaCO2 (57.01mmHg±7.87 vs. 47.39mmHg±4.5) and pH (7.39±0.03 vs. 6.8±1.3). Results indicated that Leptospira infection in hamsters is a good experimental model to study leptospirosis. However, some of the immune parameters showed variations which might be associated with the animal species

Gene Expression Profiles of Immune Mediators and Histopathological Findings in Animal Models of Leptospirosis: Comparison between Susceptible Hamsters and Resistant Mice

“…Biological activities of TNF-␣ in neutrophil recruitment to lungs and its involvement in ARDS have been previously documented (32). Interestingly, the NO pathway was associated with ARDS in a human case of leptospirosis, and NO production was evidenced in bronchoalveolar fluid and alveolar macrophages of hamsters infected with L. interrogans serogroup Icterohaemorrhagiae (27,63). Thus, high levels of expression of proinflammatory cytokines in hamster lungs could be related to alterations by acting on diverse pathways, including attraction and activation of immune cells and the NO pathway.…”

Pulmonary Disease in Hamsters Infected with Leptospira interrogans: Histopathologic Findings and Cytokine mRNA Expressions

“…These results underscore our previous report on lepstopira-induced lung dysfunctions in those animals, as assessed by gas exchange impairment and alveolar macrophage activity. 21 Arean 22 and Comby and others 23 necropsy reports on cases of fatal human (Weil's disease) leptospirosis described different degrees of pulmonary compromise according to the lesions presented, particularly characterized by areas of hemorrhaging, edema, capillary congestion, and small foci of leukocytes infiltrate. Leukocytes infiltration, (neutrophils and mononuclear cells on acute and chronic phase, respectively) alveolar congestion, interstitial pneumonia, and hemorrhagic foci were found in the lungs of the hamsters injected with L. interrogans in the present study.…”

Evaluación de los cambios fisiometabólicos en perros de 60 días de edad con traqueostomía expuesta al oxígeno directo

“…La gasometría sanguínea es una herramienta que se ha usado para monitorear el intercambio gaseoso y la homeostasis en el equilibrio ácido-base, bajo condiciones patológicas. Se ha empleado en una amplia gama de modelos animales tales como lechones 1 , cerdos 2 , cobayos 3 , conejos 4 , ratas 5 , hámsteres 6 , equinos 7 , ovinos 8 , pollos 9 , pavos y patos 10 , y perros 11 . En los humanos se ha utilizado en neonatos 12 y lactantes 13 , así como en el diagnóstico de ciertos trastornos alérgicos respiratorios 14 .…”