COMPLEMENT FIXATION REACTION 231 



Cnule lecithins from different sources vary in efficiency, heart lecithin 

 being more active than liver lecithin, brain and egg yolk lecithin follow- 

 ing. Pure lecithin is not effective, the activity of lipoid solutions 

 depending upon some other substance which is difficult to separate 

 from lecithin (MacLean).^^ Addition of cholesterol to the lipoid 

 solutions increases greatly their activity. ^^ An acetone-precipitated 

 "antigen" of this class is not a true antigen, however, for fixation 

 antibodies are not developed in animals injected with such a lipoid 

 which has been shown to be entirely efficient in the Wassermann 

 reaction. ^^ 



As for the substance in the syphilitic serum which participates in 

 the Wassermann reaction, it would seem to be related to the globulins, 

 which are decidedly increased in the blood and spinal fluid^'' of syphili- 

 tics,^** especially the euglobulin.^'' P. Schmidt^' ascribes the reaction 

 to the physico-chemical properties of the globulins of the syphilitic 

 serum, which, he believes, possess a greater affinity for the colloids 

 of the antigen than normal globulins; this affinity is held in check in 

 normal serum by the albumins of the serum, which are relatively or 

 absolutely decreased. That physico-chemical factors do play a part 

 is evidenced by the common observation that the turbidity of the 

 antigen suspension is closely related to its efficiency, clear solutions 

 being less active. Slight changes in H-ion concentration will change 

 a reaction from negative to positive, or reverse; and neutral salts can 

 change a negative to a positive reaction, but not the reverse (Gumm- 

 ing.) "^^ The lipoids in syphilitic sera are said by Peritz^^ to be 

 increased, but the lipoid content and the antibody titer do not show 

 any constant relation (Bauer and Skutezky).''^ The cholesterol con- 

 tent of syphilitic blood shows no evidence of a quantitative relation tb 

 the Wassermann reaction. ^^ Friedemann^^ believes that a globulin- 

 soap compound is the active substance in syphilitic sera. Mcintosh" 

 says that the active component differs from typical antibodies in not 



^^ Monographs on Biochemistry, "Lecithin and Allied Substances," London, 

 1918. 



5" Browning et al, Zeit. Immunitat., 1912 (14), 284; Jour. Pathol, and Bact., 

 1911 (16), 135 and 225. Klein and Fraenkel believe the "antigen" of ox heart 

 extracts to be a combination of lecithin with cholesterol and small amounts of 

 a soap-like substance similar to jecorin (Miinch. med. Woch., 1914 (61), 651.) 



" Fitzgerald and Leathes, Univ. of Calif. Publ., Path., 1912 (2), 39. 



«8 Pfeiffer, Kober and Field, Proc. Soc. Exp. Biol., 1915 (12), 153. 



" See Rowe, Arch. Int. Med., 1916 (18), 455. 



«« MuUer and Hough, Wien., klin. Woch., 1911 (24), 167. 



" Zeit. f. Hyg., 1911 (69), 513. See also Hirschfeld and Klinger, Zeit. Immuni- 

 tat., 1914 (21), 40. 



" Jour. Infect. Dis., 1916 (18), 151. 



" Zeit. exp. Path., 1910 (8), 255. 



«* Wien. klin. Woch., 1913 (26), 830. 



«5 Weston, Jour. Med. Res., 1914 (30), 377; Stein, Zeit. exp. Med., 1914 (3), 

 309. 



« Zeit. f. Hyg., 1910 (67), 279. 



6^ Zeit. Immunitat., 1910 (5), 76. 



