On a specific pneumococcus antitoxin.

Abstract

Specific pneumococcus antitoxins have been produced in this laboratory by various procedures, including those of Dochez, Larson, and the procedure developed in this laboratory by one of the authors (Olson), using a specific pneumococcus toxin.

The Larson procedure, which consists of injecting whole culture, appropriately attenuated, by means of a highly purified castor oil soap, has been extensively employed by us, using principally rabbits and sheep. Recently somewhat better yields of antitoxin have been obtained by injecting subcutaneously into rabbits, sheep or horses, progressively increasing doses of the sterile pneumococcus toxin.

The same pathological lesions were observed in the larger animals after the injection of successive large doses of toxin, as had previously been noted in smaller experimental animals and reported in a previous paper.

The highest concentration of antitoxin has been secured by starting with a very small amount of toxin and gradually increasing the size of the dose.

The procedure now adopted in testing each lot of antitoxin before using it experimentally on cases of human pneumonia, are as follows:

(1) The rabbit Skin Test. A series of dilutions of the antitoxin are mixed in equal proportions with a given concentration of the toxin, such that 0.1 cc. of the mixture contains twenty-five skin test doses of the toxin. The solutions in question are then incubated for a period of one to two hours and a considerable series of skin tests are carried out on a series of rabbits, using 0.1 cc. doses of the solutions in question. In this manner the amount of serum (required to neutralize twenty-five skin test doses of toxin is determined. The law of multiple proportions appears to hold approximately for the neutralization of double or quadruple the number of skin test doses of a given toxin by a given antitoxin.