738 THE SPIROCILETE OF SYPHILIS 



serum and guinea-pig complement, fix the complement ; hence the conclusion 

 that in syphilis the serum contains anti-bodies. Wassermann devised a 

 clinical method for the diagnosis of syphilis based on this observation and 

 deduction. It may be stated as follows : 



1. If an hsemolytic system (p. 232) be added to a mixture of extract of 

 syphilitic liver, heated syphilitic serum and complement, no haemolysis occurs. 



2. If an hsemolytic system be added to a mixture consisting of the same 

 extract of liver, heated non-syphilitic serum and complement, hsemolysis 

 occurs there has been no fixation of complement. 



3. Further, if the cerebro-spinal fluid from a case of general paralysis or 

 tabes (diseases which are known to be of syphilitic origin) be mixed with an 

 extract of a syphilitic liver and complement the latter is fixed as in the case 

 of a syphilitic serum. 



Experience has shown that there are certain exceptions to the above rules. 

 The reaction is, as a rule, positive in the secondary stage of syphilis where 

 lesions are present (65-80 per cent.). The percentage of cases in which positive 

 results are obtained is smaller in primary syphilis, and also and especially 

 when the disease is of long standing and when at the time of examination no 

 symptoms are manifest (20-58 per cent.). It is often negative in cases 

 even when they are of recent origin which are being treated with mercury 

 (ca 30 per cent.). Finally, experiments have been recorded in which a 

 positive reaction has been obtained with the serum of persons free from 

 syphilis and with the serum of non-infected monkeys. 



The reaction is therefore only reliable when it is distinctly positive. A 

 negative reaction merely constitutes a presumption in favour of the non- 

 existence of syphilis. 



In general paralysis, Wassermann's reaction is nearly always positive if 

 the cerebro-spinal fluid be used in the test (93 per cent.), but often negative 

 if the blood serum be employed (58 per cent.). It follows therefore that the 

 cerebro-spinal fluid should always be used in these cases. 



The nature of Wassermann's reaction. Wassermann's reaction is not, how- 

 ever, to be explained on the assumption that syphilitic anti-bodies are present : 

 Armand-Delille, Levaditi and Marie, and others repeating Wassermann's 

 experiments were soon able to show that the same results are obtained when 

 an extract of the liver of a new-born but non-syphilitic infant is substituted 

 for the liver of a syphilitic infant. This observation proves that there is no 

 analogy between the extract of syphilitic liver and a true antigen. And 

 Levaditi and Marie have also shown that the cerebro-spinal fluid in general 

 paralysis which gives the Wassermann reaction contains no true syphilitic 

 anti-bodies ; for it is incapable of destroying or diminishing the virulence 

 of the treponema in vitro. 



Finally Landsteiner, Levaditi and Yamanouchi, Forges and others have 

 shown that the reason why the liver extract, in the serum-reaction in syphilis, 

 is able to fix the complement is because it contains certain well-defined sub- 

 stances soluble in alcohol lecithin on the one hand, and bile salts on the 

 other. In Wassermann's reaction the extract of liver can be replaced by an 

 emulsion or solution of these substances. 



Levaditi and Koche conclude that the serum-reaction in syphilis would not 

 appear to be due to the interaction of antigen and anti-body in the ordinarily 

 accepted meaning of those terms and is, further, in no way connected with 

 the presence of the treponema. The fact would appear to be rather that 

 during an attack of syphilis " the serum becomes enriched in certain colloidal 

 principles which in presence of lipoids and bile salts are easily precipitated 



