Immunohistochemical and In Situ Hybridization Studies of Influenza A Virus Infection in Human Lungs

Abstract

Influenza viruses are responsible for acute febrile respiratory disease. When deaths occur, definitive diagnosis requires viral isolation because no characteristic viral inclusions are seen. We examined the distribution of influenza A virus in tissues from 8 patients with fatal infection using 2 immunohistochemical assays (monoclonal antibodies to nucleoprotein [NP] and hemagglutinin [HA]) and 2 in situ hybridization (ISH) assays (digoxigenin-labeled probes that hybridized to HA and NP genes). Five patients had prominent bronchitis; by immunohistochemical assay, influenza A staining was present focally in the epithelium of larger bronchi (intact and detached necrotic cells) and in rare interstitial cells. The anti-NP antibody stained primarily cell nuclei, and the anti-HA antibody stained mainly the cytoplasm. In 4 of these cases, nucleic acids (ISH) were identified in the same areas. Three patients had lymphohistiocytic alveolitis and showed no immunohistochemical or ISH staining. Both techniques were useful for detection of influenza virus antigens and nucleic acids in formalin-fixed paraffin-embedded tissues and can enable further understanding of fatal influenza A virus infections in humans.

Histopathological and immunohistochemical findings of 20 autopsy cases with 2009 H1N1 virus infection

“…The distribution of InfA-NP in cases 5-10 was similar to that observed in seasonal influenza virus infection. 25 Their histopathological findings and the causes of death, which included secondary bacterial pneumonia, were also similar to those of seasonal influenza ( Table 2).…”

“…The histopathological findings described above are common in cases of seasonal influenza, 24,25 past pandemic influenza, 26,27 and H5N1 avian influenza. 22,28 However, these findings are not specific to influenza virus infection.…”

Modification of the Ferret Model for Pneumonia From Seasonal Human Influenza A Virus Infection

“…4 Therefore, this is a suitable animal model for pneumonia caused by seasonal influenza in humans. In the meantime, seasonal H1N1 has been replaced by pandemic (H1N1) 2009.…”

Virus de la influenza

“…Los métodos tradicionales de diagnóstico incluyen el aislamiento viral o la serología (11,12), la detección del genoma viral mediante la hibridación in situ o PCR de transcripción inversa en tiempo real (realtime reverse transcriptase PCR, rRT-PCR) para evaluar la expresión génica en los tejidos y células (13,14,15), y la detección de antígenos mediante anticuerpos monoclonales y policlonales en los tejidos fijados con formol e incluidos en parafina utilizando métodos inmunohistoquímicos (16)(17)(18).…”