Effect of Infection with Trypanosomes on the Development of Experimental Allergic Neuritis in Rabbits

Abstract

DATA obtained from hospitals in western Nigeria¹ have shown that rheumatoid arthritis is uncommon in that region and, when the disease occurs, it is clinically milder than in Europeans, involving few of the expected immunological changes^2,3. Other conditions in which auto-immune processes are thought to be involved were also found to be rare, and Greenwood suggested that repeated exposure to parasitic infections might be responsible, at least in part, for the infrequent occurrence of these auto-immune diseases. Infection with the rodent malaria parasite Plasmodium berghei yoelii delayed the onset of haemolytic disease in 4 week old NZB mice and prevented the development of renal disease in (NZB×NZW) F₁ mice at the same age⁴. The severity of adjuvant arthritis in rats was also reduced by simultaneous inoculation of P. berghei yoelii, which produces a very mild infection, but not by infection with a more virulent strain of P. berghei berghei⁵. We are investigating the effects of trypanosome parasites on the development in rabbits of experimental allergic neuritis (EAN), a demyelinating paralytic disease⁶, the genesis of which is primarily a cell-mediated type of immune response (manuscript in preparation), and the preliminary results are reported here.