Large quantities of soluble antigen-antibody complexes form in the blood and are not completely removed by macrophages. These antigen-antibody complexes lodge in the capillaries between the endothelial cells and the basement membrane. The antigen-antibody complexes activate the classical complement pathway and complement proteins and antigen-antibody complexes attract leukocytes to the area. The leukocytes then discharge their killing agents and promote massive inflammation. This leads to tissue death and hemorrhage.

Flash animation illustrating Type-III Hypersensitivity: Immune Complex .swf by Gary E. Kaiser, Ph.D.
Professor of Microbiology, The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at https://cwoer.ccbcmd.edu/science/microbiology/index_gos.html.

Last updated: August, 2019
Please send comments and inquiries to Dr. Gary Kaiser