TECHNIQUE FOR DETERMINATION OF OPSONIC INDEX. l8l 



the focus of infection, lead to auto-inoculations, which are manifested in a 

 change of the opsonic index. Such artificial production of auto-inoculation 

 can be employed in various forms as a means of diagnosis : thus, in articular 

 rheumatism, massage; in pulmonary tuberculosis, breathing exercises; in 

 laryngeal diseases, loud reading; and in tuberculosis of the lower extremities, 

 active gymnastics will occasion changes in the opsonic curve. 



An example is given in Chart 7. The patient was a woman with a swollen wrist joint. 

 In order to decide whether this was a gonorrheal or tuberculous process, the opsonic 

 index was taken and found to be 0.94 to 0.97 for the gonococcus and 1.03 to 1.35 for the 

 tubercle bacillus. As these figures differed very slightly from the normal, the test was 

 repeated, but this time after Bier's hyperemia had been applied and the forearm placed 

 into warm water for one hour. The opsonic index for the tubercle bacillus remained 

 the same, while that for the gonococcus had undergone marked variations. 



A similar experiment with a woman having tuberculous lymphadenitis is given in 

 Chart 8. 



Wright makes use of these variations of index caused by auto-inoculation 

 in determining the prognosis of a case. An infection is only then considered 

 cured when artificial auto-inoculation is no longer -possible. 



The Technique for the Determination of the Opsonic Index. 



For the determination of the opsonic index are required, 



1. Serum of the patient. 



2. Serum of the normal individual (as control). 



3. Washed blood cells (Leucocytes). 



4. Bacterial emulsion. 



The blood serum is obtained from the finger tip at the root of the nail. 

 It is most efficacious to first produce a hyperemia of this part by constricting 



FIG. 18. FIG. 19. FIG. 20. 



the finger either with a narrow gauze bandage or a small soft rubber tube 

 (editor has found the latter much more convenient). The. prick is then 

 made with a needle or finely drawn out glass tube. The blood flows sponta- 

 neously and is collected into one of Wright's capillary tubes (Fig. 19) approxi- 



