THE RELATION OF LIPOIDS TO IMMUNITY 521 



show certain lipoids and lipoidal substances may act as true antigens 

 and produce antibodies. 1 This, however, has not been definitely proved, 

 and while it is of great importance, is not necessarily pertinent to the 

 subject in hand. As the relation of lipoids to various immunologic 

 processes has frequently been described in earlier chapters, as, e. g., 

 where the role of lipoids in venom hemolysis, in the Waesermann syphilis 

 reaction, and in the various precipitin reactions in syphilis were con- 

 sidered, a brief resume* may be of service in directing attention to this 

 important and particular phase of immunity. 



Relation of Lipoids to Hemolysis. (a) From the standpoint of 

 immunity, venom hem,olysis is of peculiar interest as indicating the pos- 

 sible important relation of lipoids to hemolytic complement. Granting 

 that venom contains a hemolytic amboceptor (Flexner and Noguchi), 

 the complementing substance must be derived from the corpuscles, and, 

 according to Kyes, this complementary agent is represented in lecithin. 

 Kyes was able to produce what he cpnsiders are compounds of the hemo- 

 lysin with lecithin, namely, "lecithids." Whether these "lecithids" 

 are true compounds of hemolysins and corpuscular lecithin or simply the 

 active hemolytic products of the cleavage of lecithin by ferments con- 

 tained in the venom, is at present unknown. Noguchi and Lieberman 

 have shown that not only lecithin, but soap as well, especially unsatu- 

 rated fatty acids, and probably protein compounds of soaps and lecithin, 

 may act as the hemolytic complement and activate the hemolysin of the 

 venom. Lipoids from bacteria and trypanosomes have been found to 

 possess similar properties. Hemolytic lipoids have been secured from 

 serum, and the complementary activity of a fresh normal serum may be 

 destroyed by fat solvents, e. g., ether. While other investigators have 

 not been able to confirm Noguchi's attempts to produce an artificial 

 complement of fatty substances of exactly the same properties as serum 

 complement, this work indicates most strongly the close relation of 

 serum complement to lipoids. 



(b) The hemotoxic activity of various toxins is probably dependent 

 largely upon their action on the lipoids of red corpuscles. The saponin 

 substances, 2 a group closely related to glucosids, and found in at least 

 46 different families of plants, are strongly hemolytic. Ransom 3 has 



1 Bibliography on Lipoids and Immunity given by Landsteiner, Kolle and 

 Wassermann's Handbuch, 1913, 2, 1240. Also review of literature by Landsteiner, 

 Jabresb. Immunitat, 1910, 6, 209. 



2 Complete literature on saponin, see Robert "Die Saponinsubstanzen " Stutt- 

 gart, 1904 



3 Deut. med. Wochenschr., 1901, 27, 194. 



