Einstein (São Paulo)
Print version ISSN 1679-4508
MARCHIORI, Roberta et al. Pandemic influenza A/H1N1: comparative analysis of microscopic lung histopathological findings. Einstein (São Paulo) [online]. 2012, vol.10, n.3, pp. 306-311. ISSN 1679-4508. http://dx.doi.org/10.1590/S1679-45082012000300009.
OBJECTIVE: To analyze the histopathological lung findings of four fatal cases of the 2009 H1N1 influenza pandemic and their correlation with clinical and epidemiological characteristics. METHODS: Descriptive data from medical records of four patients who died in the Intensive Care Unit of a university hospital in 2009. Nasopharyngeal aspirate specimens were collected from the patients and were analyzed by real-time polymerase chain reaction. Lung biopsy was performed post mortem; a score of intensity for pathological changes was applied. RESULTS: Three patients had positive real-time polymerase chain reaction (although all of them had a clinical diagnose of influenza H1N1). The main histopathological changes were: exudative diffuse alveolar damage with atelectasis; varying degrees of alveolar hemorrhage and edema, necrosis and sloughing of the respiratory epithelium in several bronchioli; and thrombus formation. One of the patients (the pregnant one) presented histopathological findings of cytomegalic inclusion. CONCLUSION: The pulmonary histopathological findings in patients with fatal 2009 H1N1 influenza pandemic disclosed intense alveolar damage and hemorrhage and severe bronchiolitis. A co-infection with cytomegalovirus was described in the pregnant patient.
Keywords : Influenza A virus, H1N1 subtype; Pandemics; Intensive care units.