SPECIFIC ANTIPNEUMOCOCCAL IMMUNITY IN RELATION TO THE CHEMOTHERAPY OF PNEUMONIA 12

Abstract

Of the 94 patients with pneumonia, 63 developed specific antibodies as detd. by the passive protection of mice. 59 of 84 patients who recovered possessed measurable specific immunity. 6 of 10 patients who died gave positive protection tests. 8 of 22 patients with Type III pneumococcus pneumonia produced detectable immunity. 58 of 72 patients with Types I, II, V, VII, and VIII pneumococci gave positive serological tests. In relation to day of treatment, rather than day of disease, excess antibodies were present in 15 instances before therapy was begun, in 18 instances by the 3d day of hospitalization, in 32 instances after the 3d day, and in 29 instances all tests were negative. Although the majority of the whole group of patients developed measurable amts. of specific immunity, the presence or absence of demonstrable antibodies did not, in some instances, decisively separate the patients who satisfactorily responded to chemotherapy from others whose convalescence was delayed. Since only free unbound antibodies are detectable by the methods employed, it is apparent that a negative serological reaction may be due to the fact that, (a) no antibodies have been developed following infection, or (b) all of the antibody was bound to antigen and, as a result, no excess was detectable. In the latter instance, the antibody production by the patient may have been highly effective in neutralizing antigen even though the serol. tests were negative. The use of chemotherapy is primarily successful by reducing the amount of antigen through the untoward effect of the drugs on the microorganisms. The decrease in antigen effected by the drugs brings about a relative increase in antibodies. Specific antibodies are used up in the process of combining with pneumococci, whereas exptl. studies have not up to the present time indicated that sulfonamide drugs are operative through permanent combination with bacterial cells. Consequently, increments of the drugs that are not inactivated or excreted may remain free for continuous action. However, diverse conditioning elements, not regularly controlled by specific antibodies, may account for the unsuccessful use of chemotherapy.