VENOM HEMOLYSIS IN SYPHILIS 407 



VENOM HEMOLYSIS IN SYPHILIS 



The first application of venom hemolysis was made by Weil, 1 who 

 found, in testing the hemolytic powers of cobra venom with cells derived 

 from persons suffering from different diseases, that the red cells of syphil- 

 itic individuals offered a characteristic resistance. Various explanations 

 have been offered for this phenomenon: 



1. It was argued that the quantity of red-cell lecithin is actually 

 diminished in syphilis after the primary stage because pallidum toxin 

 attacks the same lipoidal substances of tissue cells as does cobra venom, 

 in this way accounting for the diminished amount of lecithin that can 

 be extracted in syphilis, as compared with that obtained from normal 

 tissues. Accordingly, the increase in resistance is only apparent, and 

 is due rather to the fact that there is insufficient endocomplement for 

 the venom amboceptor. 



2. Another explanation offered was that the increased resistance of 

 the red cells of syphilitic persons to venom hemolysis is due to the fact 

 that pallidum toxin attacks endocomplement, and that the cells become 

 specifically immunized to this deleterious influence in much the same 

 way that repeated injections of such a hemolytic agent as saponin leads 

 in rabbits to the production of red cells, which show a marked resistance 

 to saponin hemolysis but not to any other hemolytic agent. 



3. Pallidum toxin was believed to so affect the lecithin content of red 

 cells as to render a smaller quantity of it available in a free state for 

 union with the venom amboceptor to form the hemolysin. 



4. Another theory advanced was that pallidum toxin effects a dis- 

 sociation of red cells between lecithin and cholesterin, the latter sub- 

 stance causing inhibition of hemolysis. 



Whatever may be the true explanation, the fact has been quite well 

 attested that the red cells of a large percentage of persons in the tertiary 

 stage of syphilis exhibit a characteristic increased resistance to venom 

 hemolysis, and while the cobra hemolysis test in this disease is of second- 

 ary importance to the Wassermann reaction as a diagnostic procedure, 

 yet it represents one of the most interesting of biologic phenomena, and 

 may possibly be employed in other clinical methods. 



TECHNIC OF THE COBRA VENOM TESTS 



Preparation of Venom Solution. A 1 : 1000 stock solution of dried 

 cobra venom is prepared by accurately weighing out 0.01 gram of dried 



1 Proc. Soc. Exper. Biol. and Med., 1909, vi, 49; ibid., 1909, vii, 2; Jour. Infect. 

 Diseases, 1909, vi, 688. 



