The Effects of Maternal Ethanol Consumption on Lactational Transfer of Immunity to Trichinella spiralis in Rats

Transient immunity to the intestinal parasite Trichinella spiralis can be transferred from the mother to the neonate during lactation. The goal of this study was to determine whether maternal ingestion of ethanol during pregnancy and lactation inhibited expression of anti‐ T. spiralis immunity in nursing pups. Groups of female rats were infected with 1000 T. spiralis L 1 larva, mated, and fed either ethanol‐containing or isocaloric liquid diets and maintained on diets through pregnancy and lactation or were fed the liquid diets for 30 days before T. spiralis infection, mated, and maintained on diets through pregnancy and lactation. Pups were challenged orally with 200 T. spiralis larva at 14 days postdelivery (preweaning period) or 21 days postdelivery (postweaning period) and were sacrificed either 3 or 8 days after respective challenge. Intestinal worm counts and serum titers of anti‐ T. spiralis IgG antibodies were determined for each pup. No difference in the number of intestinal worms between pups of ethanol‐treated and pair‐fed dams that received ethanol diet after T. spiralis infection was observed in the preweaning period. This was also true of pups from the dams sacrificed at 3 days after challenge in the postweaning period. However, similar pups sacrificed at 8 days after challenge showed significantly higher worm counts (decreased immunity) relative to their pair‐fed controls. Pups of dams that received ethanol containing diet 30 days prior to T. spiralis ‐infection showed significantly higher numbers of intestinal worms relative to pair‐fed pups at both the preweaning and postweaning periods. The dams receiving ethanol after T. spiralis ‐infection and their pups showed significantly lower titers of specific IgG antibodies than pups of pair‐fed control animals during the preweaning period. Dams fed ethanol diet prior to T. spiralis ‐infection and their suckling pups were not different from pair‐fed animals in serum IgG antibody levels at the preweaning or postweaning period. These results showed that maternal ethanol consumption can adversely influence the transfer of lactational immunity to T. spiralis in suckling neonates. This effect was greatest when ethanol was administered to the dam prior to infection of the dam with T. spiralis. The depression of lactational immunity was not completely related to alterations in specific anti‐bodies but could be associated with defects in Cell mediated immune responses.