LEUCOCYTOSIS AND OPSONIC CONTENT OF SERUM 39 



Exp. II. Rabbit. (-5 gm. intraperitoneally at 1*15 p.m.). 



i-i5p.m. 2-30 p.m. 3-30 p.m. 5 p.m. 9 p.m. 



Opsonic Index. I'o '85 i-i -96 -^^ 



A notable feature was a rather prolonged negative phase (as in 

 Exp. I.), which was not, however, followed by a high opsonic tide. 



v.— On the reduced phagocytic power of the neutrophile 

 leucocytes during the period of hyperleucocytosis. 



We have seen that, under conditions, in which the polynuclear 

 leucocytes are greatly in excess in the blood stream, there may be 

 no appreciable change in the opsonic content (sod. cinnamate and 

 tallianine experiments) as measured by normal leucocytes. 



It seemed to us, therefore, a question of importance to determine 

 whether the opsonic index would be altered by employing leucocytes 

 drawn during the period of hyperleucocytosis as phagocytes in the 

 in vitro test. The results of a series of experiments in this connection 

 will be found on the next page. 



It will be seen that the employment of the newly-formed polynuclear 

 leucocytes, as phagocytes in the opsonic test, invariably lowers the opsonic 

 index, and sometimes very considerably. The new leucocytes, in fact, 

 appear to have their phagocytic powers very feebly developed. Now, it 

 is obvious that, what one may call the " real opsonic index," must be 

 measured by the serum and leucocytes of the same animal taken at 

 the same time. In those cases, therefore, where the opsonic content 

 of the serum remains fairly constant (sod. cinnamate and tallianine), the 

 real opsonic index will be very much lowered during the period of 

 hyperleucocytosis or of relative neutrophilia. Again, in experiments 

 with nuclein and autolysed cultures, the real opsonic index will still be 

 much higher than in the control {vide Exps. III. and IV., Table), but 

 not so high as when normal leucocytes are employed in the test. The 

 above results have obviously a bearing on the question of vaccine-therapy 

 in man, where possible variations in the phagocytic power of the 

 leucocytes during vaccinal leucocytosis may influence considerably 

 the real opsonic index. Any increase in the opsonic content of the 

 serum might be neutralised, or rendered unavailable to the organism, 

 by deficient phagocytic power on the part of the leucocytes. 



(359) 



