CHAPTER LXII 



THE COMPLEMENT FIXATION REACTION 

 WITH BACTERIAL ANTIGENS 



AUGUSTUS VVADSWORTH 



Division of Laboratories and Research, New York State 

 Department of Health, ^^Ibany, N.Y. 



The fixation or inhibition of complement by specific immune serum in the pres- 

 ence of a homologous specific antigen is, perhaps, the most sensitive of all the immune 

 reactions, with the possible exception of those reactions in which the hypersensitive 

 animal is utilized. Although the reactions that are based upon the hypersensitivity 

 of the tissues may be more sensitive, they are standardized with greater difficulty 

 and, in general, are not so readily adapted to the routine diagnosis of infection. None 

 of the precipitin tests for the diagnosis of syphilis have yet equaled complement 

 fixation. Corresponding as it does to the Pfeiffer test in principle, and based as it is 

 upon the reactions described by Bordet and Gengou,' complement fixation is capable 

 of more sensitive adjustment than either the agglutinative or precipitative activities 

 of serum. 



It is perhaps interesting to note that the first attempts to adapt the Bordet- 

 Gengou phenomenon to the diagnosis of infection were made by both Bordet^ and 

 Wassermann^ with antigens of the tubercle bacillus. These early attempts, however, 

 were abandoned on account of unsatisfactory results; and Wassermann^ turned to 

 the diagnosis of syphilis by the test which, although primarily based upon what were 

 considered specific relations, has now become so modified by experience, empirically, 

 as to subordinate the specific relations upon which it was originally based. Neverthe- 

 less, the practical results with it during the past twenty years must obviously con- 

 vince one that there are specific relations in it, even as now performed without specific 

 antigens. This is a most important fact to bear in mind. 



Meanwhile, the complement fLxation reaction has been studied with one after 

 another of the bacterial antigens. In all this application of the test with the bacterial 

 antigens, specific relations have been maintained. The antigens have all been prepara- 

 tions of bacterial culture material.^ 



The earliest antigens were simply suspensions of the bacterial cell, either in the 

 original culture or washed and suspended in physiological salt solution. Similarly, 

 concentrated culture material, such as tuberculin, was also tested. With the serum 



' Bordet, J., and Gengou, O.: Ann. Vlnst. de Pasleiir, 15, 289. 1901. 

 ^ Bordet, J., and Gengou, O.: ibid.; Compt. rend. Acad, de sc, 137, 351. 1903. 

 3 Wassermann, A. P., and Bruck, C: Deutsche med. Wchnschr., 32, 449. 1906. 

 "I Wassermann, A. P., and Neisser, A., and Bruck, C: ibid., p. 745. 1906. 

 5 The observations of Warden (Warden, C. C, and Schmidt, L. E.: /. Lab. Clin. Med., i, 333. 

 1915-16), suggest the possibility of the development of a reaction with non-specific lipoidal antigens. 



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