Properdin-mediated immune ring formation associated with Pseudomonas keratitis.

To the Editor. —Wessely immune rings of the cornea have been described to occur after infectious corneal ulcers. These rings are composed of polymorphonuclear leukocytes, which collect in a discrete circular region of complement activation around the antigenic entry site. It has long been accepted both experimentally and clinically that the antigenantibody-mediated or classical pathway of complement activation results in a visible Wessely ring ten to 14 days after infection. More recently, Mondino et al 1 have shown in an animal model that the properdin-mediated or alternate pathway of complement activation exhibits ring formation one to two days after injection of Pseudomonas aeruginosa or Pseudomonas endotoxin. Additionally, Mondino et al 2 have proved that properdin can be found in the limbus of normal human corneas. However, to our knowledge, a human correlate of immune ring formation within the time course of properdin-mediated complement cleavage has yet to be described in