SERUM REACTIONS 251 



significance, and may occasionally be of use in diagnosis when lumbar 

 puncture fails to give positive results. Although their presence in large 

 amounts may be said to indicate a marked reaction, they do not supply 

 information of much value in relation to prognosis. Immune-bodies, as 

 shown by bactericidal and deviation of complement tests (pp. 122, 127), 

 may also be developed in considerable amount in the course of the disease. 



Anti-sera for therapeutical purposes have been introduced by 

 various workers, and of these the one which has been most 

 extensively used is that of Flexner and Jobling. This serum 

 is prepared from the horse by repeated injections in increasing 

 doses of dead cultures, followed by injections of culture autolysate 

 and of living cultures, these two latter being best administered 

 by the subcutaneous method. Several strains of meningococci 

 are mixed together for purposes of injection, and the immunisa- 

 tion is continued over a period of several months. For treat- 

 ment of the disease the serum is injected under the spinal dura, 

 30 c.c. being generally used for an injection in an adult, this 

 being repeated on subsequent days.^ Some of the spinal fluid 

 is removed and then the serum is injected, undue pressure being 

 avoided. This serum has been used on a large scale in various 

 parts of the world, and there is general agreement as to its 

 favourable effects — the mortality of the disease, which is gener- 

 ally 70 to 80 per cent., having been reduced to about 30 per 

 cent, or even less. By means of its use the tendency to the 

 occurrence of chronic lesions has also been markedly diminished. 

 The action of such anti-sera cannot as yet be fully explained. 

 They certainly contain opsonins, agglutinins, immune-bodies 

 which bind complement, and possibly also anti-endotoxins. 

 After the injection the number of meningococci becomes 

 markedly reduced, probably as a result of increased phago- 

 cytosis ; there can scarcely be any direct bactericidal action 

 owing to the absence of complement. Recently, monovalent 

 sera against each of the four types of meningococcus (p. 250) 

 and also a polyvalent serum have been prepared for military 

 cases by Gordon and his co-workers. The standardisation of 

 such anti-sera is a matter of some difficulty ; at first the devia- 

 tion of complement method was used (p. 127), but now the 

 opsonic index is regarded with more favour as an index of the 

 potency of the serum. Gordon has recently pointed out the 

 importance of estimating the anti-endotoxic action, and has 

 described a method for this purpose. 



Mackenzie and Martin treated cases by the intra-spinal injection of the 

 fresh serum of patients suffering from the disease or who have recovered 

 from it, such serum being in many cases rich in immune-bodies for the 



