Disease patterns in experimental allergic neuritis (EAN) in the Lewis rat: Is EAN a good model for the Guillain-Barré syndrome?

Abstract

Lewis rats develop experimental allergic neuritis (EAN) when injected with bovine dorsal root (BDR) emulsified in complete Freund's adjuvant (CFA). In this study the susceptibility to EAN and subsequent relapse was studied in animals ranging from 4 to 25 weeks of age. Older animals exhibited a severe acute illness which was monophasic over the period of observation, whereas younger animals developed a less severe and frequently relapsing illness. Very young animals often relapsed more than once and sometimes to a more severe degree than shown in their first attack. Older animals which were in the late recovery stage of EAN (44 days after injection with BDR/CFA) were completely resistant to a second challenge with antigen. Young adult animals also developed resistance but not as strongly as the older animals. Animals first injected at weaning developed resistance as in the adults, but the analysis is complicated by the occurrence of spontaneous relapses. Because of differences in disease pattern between EAN and acute inflammatory polyneuropathy (Guillain-Barré syndrome) in man, caution should be exercised in drawing too close a parallel between the animal model and the human disease. The affinities may be closer to chronic relapsing inflammatory polyradiculopathy in man.