STUDIES WITH THE TREPONEMAL IMMOBILIZING TEST

The widespread use of the standard serologic tests for syphilis and the known occurrence of a sizeable number of biologically false positive serologic tests has created a major problem in diagnosis. No solution to this problem had been offered until 1948, when Nelson¹ developed the treponemal immobilizing test. In 1949 Nelson and Mayer² reported the results of the test in man. This test differs from all of the many serologic tests in that it uses the specific antigen Treponema pallidum and an antibody distinct from reagin. Unlike reagin, which may appear in response to a variety of conditions, the immobilizing antibody develops only in response to the treponematoses: syphilis, yaws, pinta, and bejel. Analysis of the reports already published by Nelson and his group,³ Magnuson and Thompson,⁴ Mohr and colleagues,⁵ our group,⁶ Moore and Mohr,⁷ and others show agreement that the treponemal immobilizing