Apoptosis and Pathogenesis of Avian Influenza A (H5N1) Virus in Humans

• Main Authors: Mongkol Uiprasertkul, Rungrueng Kitphati, Pilaipan Puthavathana, Romchat Kriwong, Alita Kongchanagul, Kumnuan Ungchusak, Suwimon Angkasekwinai, Kulkanya Chokephaibulkit, Kanittar Srisook, Nirun Vanprapar, Prasert Auewarakul
• Format: Article
• Language: English
• Published: Centers for Disease Control and Prevention 2007-05-01
• Series: Emerging Infectious Diseases
• Subjects: Avian influenza A virus H5N1; autopsy; apoptosis; pathogenesis; lymphopenia; lung
• Online Access: https://wwwnc.cdc.gov/eid/article/13/5/06-0572_article

The pathogenesis of avian influenza A (H5N1) virus in humans has not been clearly elucidated. Apoptosis may also play an important role. We studied autopsy specimens from 2 patients who died of infection with this virus. Apoptosis was observed in alveolar epithelial cells, which is the major target cell type for the viral replication. Numerous apoptotic leukocytes were observed in the lung of a patient who died on day 6 of illness. Our data suggest that apoptosis may play a major role in the pathogenesis of influenza (H5N1) virus in humans by destroying alveolar epithelial cells. This pathogenesis causes pneumonia and destroys leukocytes, leading to leukopenia, which is a prominent clinical feature of influenza (H5N1) virus in humans. Whether observed apoptotic cells were a direct result of the viral replication or a consequence of an overactivation of the immune system requires further studies.