Complement vs. HLA – What’s the Difference?
By Dr. Kione Teta, ND, LAc · April 10, 2026 · Immunity and Vaccination Series - Part 1: 5(10)
When discussing the immune system, it’s easy to get lost in the alphabet soup: HLA, MHC, C3, CD4, IgG. Among the most commonly misunderstood acronyms are complement and HLA—two systems with very different roles but both essential to immune function.
In this section, we’ll clarify these two pillars: the complement system, an ancient biochemical kill switch, and HLA (Human Leukocyte Antigen), the molecular badge that lets the immune system distinguish friend from foe.
The complement system is a series of plasma proteins (mainly labeled C1–C9) that work together to:
This is the opening of the article. The full piece is on Kione's Substack.