Potential for hepatic and renal dysfunction during influenza B infection, convalescence, and after induction of secondary viremia.

Whether infection with influenza B virus alters hepatic function was examined in the ferret. Also, the possibility that viral-specific antibodies (Ab) could be produced well before their detection in serum was explored. During the febrile period of influenza, reductions in the serum potassium, anion gap, ammonia, albumin and CPK and elevations of the BUN, creatinine and the GGTP levels occurred. With convalescence, the electrolytes, BUN and creatinine normalized, FFA, SGPT and CPK levels rose and the serum GGTP rose even further. Hepatic fatty acid (FA) oxidation, ornithine transcarbamylase (OTC) and carnitine palmitoyltransferase (CPT) activities were minimally altered and liver ATP and total lipid content remained normal. Following experimental secondary viremia, serum FFA continued to rise, TG decreased and CPK remained elevated while SGPT and GGTP levels normalized. In the liver, FA oxidation and OTC rates remained unchanged but CPT activity was inhibited and the liver content of ATP was significantly reduced. Immune complex (IC) protein recovered from postmicrosomal supernatant fractions by polyethylene glycol precipitation was progressively increased in livers from convalescent and viremic animals. While the amount of IC protein recovered in the spleen also increases during convalescence, this is not the case after viremia when the IC formed seem to be processed largely by the liver. By SDS/PAGE, the major proteins identified in the IC were IgM and other viral proteins. However, the viral proteins could not be validated by immunoblot with Ab produced against purified influenza B hemagglutinin (HA) and neuraminidase (NA) most probably due to phagocytic alterations of glycoprotein immunodeterminants. These findings indicate that during influenza, convalescence and post viremia changes in the concentrations of several serum and liver components occur that reflect hepatic involvement. Also, antiviral Ab, largely IgM, appears to be produced early, complexes with Ag and can be found sequestered in both the liver and spleen at a time when Ab is not detectable in the serum.