Association of tumor necrosis factor-alpha with fever and pulmonary lesion score in pigs experimentally infected with swine influenza virus subtype H1N2

The relationship between tumor necrosis factor (TNF)-alpha level, body temperature, and pulmonary lesion score was determined in 3-week-old pigs inoculated intranasally with swine influenza virus (SIV) subtype H1N2. The expression of TNF-alpha was measured in bronchoalveolar lavage (BAL) fluids by enzyme-linked immunosorbent assay and lung tissues by immunohistochemistry. In BAL fluid, TNF-alpha concentration was maximal at 1 day post-inoculation (dpi), declined markedly by 3 dpi (P0.05) and steady thereafter. Mean rectal temperatures were above 40degC for the infected groups at 1 dpi and declined markedly by 3 dpi. The body temperatures were correlated with the levels of TNF-alpha in BAL fluids from pigs experimentally infected with SIV (rsub(s)