The peculiar phenomenon which is exhibited by the alcohol-soluble and acetone-insoluble lipoid obtained from various animal organs, in that it can play the role of antigen in the Wassermann test for syphilis, has been the subject of many investigations. The term antigen cannot be strictly applied to this lipoid substance since it has been conclusively shown by Fitzgerald and Leathes1 that repeated injections of this substance into rabbits do not lead to the appearance of antibodies in the blood stream. No adequate theory has been advanced which satisfactorily explains the mechanism of the reaction. It is unnecessary that the antigen be derived from the organs of syphilitic persons since the lipoid may be, and is ordinarily, prepared from certain organs of normal animals. In fact, investigators have suggested the use of such substances as sodium oleate,2 lecithin,3 and the bile salts,4 instead of the alcoholic extract of certain organs, but with the exception of cholesterol,5 which is at times added to the antigen, these have not come into general use. The technic for the preparation of the antigen used in the Wassermann reaction has been standardized by Noguchi.6 It consists in the extraction of the macerated liver, heart or kidney of certain animals with absolute alcohol, evaporation of the extract, subsequent solution in ether and precipitation of the lipoid by the addition of acetone. While this method usually yields potent preparations of antigen, it has nevertheless been noted that individual lots may at times exhibit marked antialexic [anticomplementary] properties. The antigenic value is, however, not materially affected. Although the antigen appears to be quite universally distributed in the tissues, it occurs in the largest amount in the heart, liver and
Read full abstract