Purified Protein Derivative

**Semantic type:** Amino Acid, Peptide, or Protein|Pharmacologic Substance

**Definition:** A purified protein extract derived from the bacterium Mycobacterium tuberculosis. Intradermally-administered, PPD stimulates preprimed CD4 T cells in immunologically competent subjects previously exposed to the bacterium Mycobacterium tuberculosis; these activated CD4 T cells secrete various cytokines that attract granulocytes, monocytes, and macrophages in an inflammatory response known as delayed hypersensitivity. (NCI04)

**Synonyms:** - PPD - PPD - PPD Tine Test - Tubersol