138 



Immunity 



ing to controvert the theory of Neisser and Wechsberg, and Bolton* 

 has shown that normal serum may kill relatively more bacteria when 

 diluted than when undiluted. 



THERAPEUTIC USES OF BACTERIOLYTIC SERUMS 



It was at first hoped that some of these serums and especially 

 the bacteriolytic serums would have a wide therapeutic application 

 in cases in which non-toxicogenic bacteria were 

 invading the body, but experiment and experi- 

 ence have shown that the laws governing their 

 action greatly limit their application, and that 

 their effects, when not beneficial, are bound to 

 be harmful. The difficulty lies in the fact that 

 when we manufacture such serums we prepare 

 only the immune body, there being no increase 

 of the complement. 



To introduce this by itself does the patient 

 no good, because in most cases the existing in- 

 fection has brought about the formation of as 

 much or more "immune body" than can be util- 

 ized by the complement. To give injections of 

 active bodies that cannot be utilized is shown by 

 Comus and Gleyf and KosselJ to be followed 

 by the formation of antibodies — in this case 

 "anti-immune bodies" — by which their effect 

 is neutralized. Should anti-immune bodies be 

 formed by this meddlesome medication, the 

 state of the infected animal would be worse 

 than before, because it would now be preparing 

 that which by neutralizing the combining affini- 

 ties of its own immune bodies, would prevent 

 them from combining with the elements to be 

 destroyed and so activating the complements. 

 No satisfactory method of experimentally increasing the comple- 

 ment has been devised. If, as Metschnikoff supposes, the comple- 

 ment is microcytase derived from disintegrated leukocytes, aseptic 

 suppurations with active phagolysis should result in marked increase 

 of the complement. As a matter of fact, this does take place, but 

 the increase is so slight that the serum is not practically valuable. 

 Therapeutic serums whose practical application is based upon 

 their cytolytic activity must, of necessity, contain both the essential 

 factors involved in cytolysis, and should contain them in such pro- 

 portions that, regardless of other elements in the blood, they can 

 exercise their combining and dissolving functions. 



* "The Bacteriolytic Power of the Blood-serum of Hogs," Bull. No. 95 of the 

 Bureau of Animal Industry, U. S. Dept. of Agriculture. 



t " Compte rendu de I'Acad. de Sciences de Paris," Jan. i, 1898, 126. 

 t"Berl. klin. Woch.," 1898, S. 152. 



Fig. 30. — Schemat- 

 ic representation of 

 the interfering ac- 

 tion of anti-ambo- 

 ceptors, and anti- 

 comple m e n t s. A, 

 Anti-amboceptor 

 action: c, Comple- 

 ment; am, ambo- 

 ceptor; aa, anti-am- 

 boceptor preventing 

 the amboceptor from 

 connecting with the 

 cell. B: c, Com- 

 plement; ac, anti- 

 complement pre- 

 venting the comple- 

 ment from connect- 

 ing with the ambo- 

 ceptor, am. 



