Abstract
The properdin system was shown to decrease following the preparatory intracutaneous injection in the Sh-R, but increase following excision of the local skin. This suggests that serum properdin may be attracted to the local skin. Properdin levels fell and rose after the challenge antigen and a distinct difference between the Sh-R positive and negative cases was noticed.
In Gross-Ogatg's inhibition this alteration appeared to be delayed and to be slight.
Properdin is not similar to the original Sh-antibody, and it may be included in the Sh-blocking antibody. Serum properdin is also related to the bactericidal activity in the Sh-R.
These experiments suggests that the Sh-R is a nonspecific antigen-antibody reaction between Sh-f and properdin.
