Molecular pathology analyses of two fatal human infections of avian influenza A(H7N9) virus. Issue 1 (6th November 2014)

• Record Type: Journal Article
• Authors: Feng, Yanling; Hu, Lvyin; Lu, Shuihua; Chen, Qingguo; Zheng, Ye; Zeng, Dong; Zhang, Jun; Zhang, Anli; Chen, Liang; Hu, Yunwen; Zhang, Zhiyong
• Is Part Of: Journal of clinical pathology. Volume 68:Issue 1(2015)
• Page Start: 57
• Page End: 63
• Publication Date: 2014-11-06
• Subjects: H7N9 influenza virus -- in situ hybridization -- inflammatory response;; Pathology -- Periodicals; Pathology, Molecular -- Periodicals; 616.0705
• DOI: 10.1136/jclinpath-2014-202441
• Languages: English
• ISSNs: 0021-9746

Abstract

Abstract : Aims: To investigate the histopathological manifestations of two fatal cases of H7N9 influenza A virus infection. Methods: Pulmonary and hepatic specimens from two fatal cases of H7N9 influenza virus infection were examined using H&E staining. Additionally, in situ hybridisation was performed with probes (ViewRNA) targeting H7N9 RNA and IP-10, interleukin (IL)-6 mRNA. The distribution of surfactant protein A (SP-A), surfactant protein B (SP-B), CD3, CD4, CD8, CD68 and C4d were determined with immunohistochemistry. Results: Apart from the typical diffuse alveolar damage and hyaline membrane observed in severe influenza infection, we detected H7N9 RNA and massive intrapulmonary production of IP-10 and IL-6 mRNA using in situ hybridisation. Hyperplasia of type II pneumocytes was observed by H&E staining and immunohistochemistry. Proliferating macrophages and clustered neutrophils in the infected lungs were observed, whereas T lymphocytes, especially CD4T helper cells, were markedly depleted. No obvious complement deposition was found in lung tissues. Conclusions: Our findings suggest that H7N9 influenza virus induced an immunological response towards overt pulmonary inflammation and systemic lymphopenia which led to intense alveolar damage and respiratory failure.