Hypersensitivity to acetaldehyde-protein adducts.

Acetaldehyde, the first product in the metabolism of ethanol, is known to condense with plasma proteins, forming stable adducts. We have previously shown that these adducts can be recognized as foreign by the immune system. In the present study the existence of type I hypersensitivity-mediating antibodies against these adducts was investigated in humans and in animals. Immunization of mice with acetaldehyde-protein condensates, followed by adoptive transfer of splenocytes, led to the production of IgE anti-acetaldehyde adducts. A monoclonal IgE antibody was obtained by the hybridization technique. This antibody recognized acetaldehyde adducts, independently of the carrier protein used, indicating that the acetaldehyde moiety behaves as a hapten. The affinity of the antibody for the acetaldehyde adduct of polylysine was 7 orders of magnitude higher than that for polylysine. Passive immunization by intradermal or intravenous administration of this monoclonal antibody to rats rendered the animals hypersensitive to acetaldehyde-protein conjugates, as shown by marked anaphylaxis. A study was conducted to determine the existence of naturally occurring hypersensitivity reactions to alcohol in > 1000 non-Oriental individuals. A prevalence of severe hypersensitivity reactions of 0.46% was found. The reactions were severe enough to deter these individuals from consuming all types of alcoholic beverages. Individuals presenting such reactions had significantly elevated levels of circulating anti-acetaldehyde-protein IgE antibodies.