Pathology and virology findings in cases of fatal influenza A H1N1 virus infection in 2009–2010

Abstract

The pulmonary findings are similar to those described in past pandemics. Secondary fungal and viral infections, which have not been reported previously, were noted. Although the number of cases in this study is small, the findings reinforce the notion that changes in extrapulmonary organs are attributable to multiorgan dysfunction syndrome rather than a viral cytopathic effect, and that there is no transplacental transmission of virus.

Comparison of chest-CT findings of Influenza virus-associated pneumonia in immunocompetent vs. immunocompromised patients

“…Knowingly, these varying radiological findings reflect different histopathological substrates like diffuse alveolar damage, intra-alveolar edema, variable cellular infiltrates, intra-alveolar hemorrhage and interstitial inflammatory cell infiltration at a different extent and different intensity [19]. Previous pathological reports on this issue brought evidence on the nature of pulmonary changes induced by Influenza viruses showing that, upper and lower respiratory tract infection generally leads to multifocal desquamation of the pseudostratified columnar epithelium of the trachea and bronchi or even complete loss of the epithelial layer associated or not with the formation of hyaline membranes of the bronchioles [20]. These histological changes are in the first line responsible for the presence of centrilobular nodules, tree-in-bud and air-trapping.…”

“…This latter aspect is supposed to be responsible for the peribronchial and peribronchiolar "airway centric" pattern of infiltration. In the predominantly "interstitial-parenchymal" pneumonia pattern consisting radiologically of bilateral, symmetrical GGO, crazy paving and marked reticulation, thickening of the alveolar septa by dilatation of the alveolar capillary bed, interstitial edema, and different degrees of interstitial lymphomononuclear cell infiltrates seem to represent the underlying pathological substrate [20]. Varying degrees of acute intra-alveolar edema and hemorrhage as well as the presence of interstitial small and medium blood vessels containing fibrin thrombi are also contributing to the extent and CT-morphological characteristics of this pattern.…”

Influenza a infection unmasking an underlying mitral valve stenosis in a 19-year-old boy

“…[4] Autopsy sample of young females during the H1N1 epidemic in 2009-10 showed Grade 2 mitral stenosis. [5] It further highlights the association between the two.…”

TNF-Alpha Gene Polymorphism in Indian Population during the Course of Pandemic Influenza a H1N1 Infection: A Pilot Study

“…A point mutation from C to T at -857 possessed higher transcription due to the change in the binding stability by variant allele whereas polymorphism at position -863C/A in the promoter region has been reported to be associated with reduced TNF-α promoter activity and lower plasma TNF levels [10,16]. Regarding the TNF gene, four SNPs -238, -308, -857 and -863 have been well associated with viral infections.…”

“…Till date 621 SNPs in TNF-α gene have been reported in the NCBI website , with more than 10 SNPs in the promoter region, including -238 G/A , -244 A/G, -308 G/A, -376 A/G, -575A/G, -857C/T, -863 C/A, -1031T/C [8,9]. Regarding the TNF gene, four SNPs have been well associated with the higher TNF-α production after viral infections [6,10], all at different locations within the promoter region: a substitution of guanine by adenine at the -238 position(-238 TNF G/A), a substitution of guanine by adenine at the -308 position(-308 TNF G/A), a substitution of cytosine by thymine at the -857 position(-857 TNF C/T), a substitution of cytosine by adenine at the -863 position(-863 TNF C/A).…”