OPSONINS. 



179 



Wright and his ' co-workers have noticed that an increase in the opsonic 

 index usually runs parallel with an improvement in the condition of the 

 patient. 



Inasmuch as an increase in the opsonic index is occasioned by introduc- 

 ing into the general system even a very small number of bacteria, it seems 

 probable that such spontaneous inoculation will take place during the course 

 of an infectious disease. In fact, a spontaneous rise in the opsonic index is 

 observed during convalescence or after the crisis of an infection. A high 

 index is, however, also noticed at other times, for example tuberculous individ- 

 uals show a higher index than normal persons. Wright explains this by the 



CHART. 6. Opsonic curve during treatment with New Tuberculin. 



so-called "auto-inoculation;" for example after moderate exercise, or work, 

 tuberculin is liberated from the tuberculous focus and in this way acts like a 

 therapeutic injection of tuberculin, i.e., the index will be raised. Therefore, 

 an excessively high opsonic index is of just as great diagnostic value as a low 

 one. Wright furthermore believes that constant irregularities or variations 

 in the height of the opsonic curve serve as plausible evidence for the exist- 

 ence of infection, because under normal circumstances the curve should 

 remain at a level. Not infrequently, however, cases come under observation 

 where in spite of a distinct evidence of the existence of an infection the opsonic 

 index remains normal. In such instances for some reason, the bacteria and 

 their products do not reach the general circulation and therefore no occasion 

 is offered for either an elevation or sinking of the opsonic index. Wright and 

 Freeman were able to show that all active and passive motions of an infected 

 joint, as well as any vascular changes which induce a flow of lymph toward 



