Syphilis antigen from the soya bean.

The non-specificity of "syphilis antigen" has been the subject of much speculation from the time it was first demonstrated that substances which exerted an antigenic effect in complement-fixation tests for syphilis could be extracted from nbormal mammalian tissues (Weygandt, 1907; Landsteiner and others, 1907). Further proof of the nonspecificity of these " antigenic " substances has been evidenced by their extraction from such diverse materials as fish (Neymann and Gager, 1917), scallops (Sanderson, 1928), and various microorganisms, including the M. tuberculosis and B. proteus X19 (Weil, 1941). Thus it is assumed that "syphilis antigen" is widely distributed in nature, and it is not surprising to find that it has been shown to be present in vegetable tissue: Heinlein (1912) described an antigen which he had extracted from potatoes: the antigenic reactions of peas, beans, and corn were investigated by Tribondeau (1913), who found that extracts ofpeas proved satisfactory; Walker (1917) also obtained good results with peaantigen; a large number of plants and seeds wvere investigated by Weiss (1923), who found that extracts made from olives afid coconuts contained relatively large amounts of " syphilis antigen." In view of the generally accepted belief that syphilis antigen is similar chemically to the phosphatides, vegetable material containing even moderate amounts of phosphatide might be expected to yield an antigen of fair quality. Thus the relatively high phosphatide content of the soya bean (Maclean and Maclean, 1927) suggested the use of this versatile substance as a source of antigen' for use in tests for syphilis. To investigate this possibility, various extracts made from commercial soya flour and the whole bean were tested for their ability to react with syphilitic sera: the extractions were carried out in several different ways in order to find the most promising method. The antigenic activities of these somewhat empirical extracts were examined by substituting them' for the Kahn antigen normally employed to make the reagent of a modified version of the Laughlen test which has been found extremely reliable (Stevenson, 1948).