Relationship of adjuvants and swine influenza vaccine to experimental neuropathy in rabbits.

Experimental neuropathy, characterized by endoneurial edema and demyelination, was induced by inoculating rabbits with a combination of Freund's complete adjuvant (FCA), gangliosides, lecithin and cholesterol. A less severe demyelinating neuropathy could be induced by treatment with FCA alone but no significant change could be elicited by injection of swine influenza vaccine (SFV) alone. When FCA was combined with gangliosides, lecithins, cholesterol and SFV, neuropathy occurred, but the changes were less severe than if these agents were used without SFV. Sera were tested for myelin basic protein (MBP) and galactocerebroside (GC) antibodies in each experimental group. Neither SFV alone nor SFV combined with Freund's complete adjuvant, gangliosides, cholesterol and lecithin evoked significant antibody titers to MBP or GC. However, rabbits inoculated with FCA, gangliosides, lecithin and cholesterol had rising titers of antibody to both MBP and GC over the 3-month experimental period. One rabbit inoculated with FCA alone had significant antibody to MBP. The findings suggest that Freund's complete adjuvant alone can induce demyelination in the peripheral nerves of rabbits and that SFV may modulate the immune response acting either as an adjuvant or suppressant in the experimental demyelinating disease.