THE DIAGNOSTIC VALUE OF THE LANDAU TEST 



FOR SYPHILIS 



J. BRONFENBRENNER and J. ROCKMAN 



(Pathologkal Laboratories of the Western Pennsylvania Hospital, 



Pittsburgh, Pa.) 



The specificity originally attributed to the Wassermann reaction, 

 in the sense that this reaction depends on the combination between 

 antibody in blood of the syphiHtic individual with its specific anti- 

 gen derived from syphiHtic Hver extract, is no longer tenable, since 

 it was shown that not only syphiHtic Hver but normal Hver, or any 

 other organ of human as well as animal origin, yields substances 

 that are capable in combination with syphiHtic serum to inactivate 

 or fix the complement. The extreme sensitiveness of the reagents 

 that have to be continuously titrated adds to the complexity of this 

 test. Although not specific in the original sense the Wassermann 

 reaction is, however, a fairly constant finding in syphilis, and in 

 this sense its specificity is very well established. 



Landau^ has lately described a chemical test which is not only 

 very much simpler than the Wassermann reaction but, according to 

 Landau, is also more specific. The test is based on the property of 

 syphiHtic serum (or possibly of the nonsaturated fatty acids con- 

 tained in it) to combine with iodin. In a series of 90 cases of 

 Syphilis he found the Wassermann reaction positive 49 times 

 whereas the Landau reaction was positive 55 times. In his later 

 publication Landau changed slightly the technic of this test and, by 

 doing so, markedly facilitated the reading of the results. In a series 

 of yj cases of syphilis, tested by the improved method, the positive 

 results obtained by Landau were 27 percent higher than those ob- 

 tained by Wassermann reaction. Judging from Landau's results 

 the test offers a very valuable addition to the laboratory methods now 

 in use. We therefore planned to repeat his work, and to compare 

 the results obtained by his reaction with those obtained by the Was- 

 sermann reaction, as the latter is used in our laboratory. 



1 Landau: Wien. klin. Woch., 1913, p. 1702. 



377 



