Pattern of nasal secretions during experimental influenza virus infection

To define the pattern of secretion production during influenza virus infection, 28 adult subjects were inoculated with influenza-A virus (H1N1) and cloistered for a period of 8 days. On each day, symptoms associated with virus infection were scored, nasal secretions were collected and nasal lavages were performed. Recovered lavage fluids were submitted for virus culture and assayed for proteins, histamine, and bradykinin. Twenty-one subjects were infected with influenza-A virus and had significant increases in daily secretion weights and symptom scores extending from day 2 to 7, post-inoculation. Plasma-derived proteins in the nasal lavage fluids showed an early increase to peak at day 4 and then decreased. Glandular proteins showed a later increase to peak at day 5. Bradykinin but not histamine was significantly elevated and tracked the changes in the glandular proteins. In contrast, a shallow increase in symptoms confined to day 2 post-inoculation, but no increase in daily secretion weights was documented in the seven uninfected subjects. There, an increase in plasma proteins was observed on days 1 and 2, but no change in glandular proteins was obvious. These results support a biphasic secretory response during influenza-virus infection with transudation dominating the early period and glandular secretions contributing later.