Rabbit γM antibody against human type A substance gave precipitin reactions in vitro and induced reversed Arthus type of inflammation in guinea pigs which had received A substance. Preformed complexes composed of A substance and γM antibody also induced the allergic inflammation in normal guinea pig skin. On a weight basis, the minimum dose of the γM antibody for the induction of hemorrhage in reversed Arthus reactions was two to four times as much as the dose of the γG antibody. In the reactions by the preformed complexes, a similar dose of γM and γG antibody in the form of complexes with A substance induced comparable skin reactions.
This work was supported by Research Grant AI-4985 from the United States Public Health Service.