492 THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



The technic consists in preparing the antigen and in determining its 

 anticomplementary dose. Whatever this is, one-half to one-quarter 

 this amount is added to increasing quantities of heated immune serum, 

 ranging from 0.001 to 0.1 c.c. Complement and saline solution are 

 added, and after incubating one hour at 37 C., the amount of comple- 

 ment fixation is determined by adding hemolytic amboceptors and cor- 

 puscles. 



While this titration is one measure of the reaction of the animal used 

 in the immunization, better evidence of the therapeutic value of the 

 serum is obtained by determining the content in bacteriotropins, by 

 testing the serum with the antigen in susceptible animals, or by a com- 

 bination of all methods. 



THE COMPLEMENT-FIXATION TEST IN ECfflNOCOCCUS DISEASE 



Complement-fixation tests have been advocated as aiding the diag- 

 nosis of echinococcus disease. In making the tests, hydatid cyst fluid 

 of the human or sheep is used as antigen (Ghedini). Reports upon the 

 specificity and usefulness of this reaction are somewhat contradictory, 

 although, as a rule, they are generally favorable. Cases of recent in- 

 fection with fresh active lesions may react negatively, a result that is 

 dependent presumably upon non-absorption of antigen and slight 

 antibody formation (Gaetano, 1 Weinberg and Bordin, 2 Kurt Meyer 3 ). 

 Thomsen and Magnussen, 4 in a recent study of 12 cases, found that 

 10 reacted positively. Of 55 control cases (32 of whom reacted posi- 

 tively to the Wassermann reaction), all were negative except one. Kurt 

 Meyer found the serums of echinococcus infected persons to react posi- 

 tively with antigens of other tsenia (Tsenia solium and Tsenia saginata), 

 and, conversely, the serums of persons infected with Tsenia saginata and 

 Tsenia solium to react with an echinococcus antigen. Thomsen and 

 Magnussen, however, could not support these findings, and report most 

 favorably upon the specificity of the reaction. Of 10 persons infected 

 with Tsenia saginata, 2 with Tsenia solium, and 1 with Bothriocephalus 

 latus, all reacted negatively with echinococcus antigen. 



The antigen is best prepared of the fresh fluid of an echinococcus 

 cyst of man or sheep. It should be filtered, if necessary, preserved with 



1 Gaetano: Riforma Medica, 1910, Nos. 39 and 40. Reference in Deut. med. 

 Wochenschr., 1910, No. 44. 



2 Weinberg and Bordin: Compt. rend. soc. biol., 1909, Bd. 66. 



3 Meyer (K): Berl. klin. Wochenschr., 1910, No. 28. 



4 Thomsen (O.), and Magnussen (G.): Berl. klin. Wochenschr., 1912, No. 25. 



