AAP

Meaning of AAP: AAP most often abbreviates alanine aminopeptidase, a kidney tubular enzyme measured in urine, though the identical letters separately denote a well known pediatric professional organization.

Definition of AAP

AAP most commonly abbreviates alanine aminopeptidase in laboratory and genetic contexts, an enzyme normally present within the cells lining the kidney's tubules. Small amounts of AAP are ordinarily released into urine, and the amount present can change when these tubular cells are injured.

Because AAP is released from damaged tubular cells, measuring AAP in urine is used as a biomarker to help detect kidney tubular injury, including injury caused by certain medications or toxic substances, sometimes before more traditional markers of kidney function change. Elevated urinary AAP can also be seen in certain other kidney and liver disorders.

The same abbreviation is also widely used elsewhere in medicine with an unrelated meaning, standing for the American Academy of Pediatrics, a professional organization representing pediatricians, which is the meaning most familiar to the general public. Context, such as a laboratory report compared with a discussion of pediatric guidelines, generally makes clear which meaning is intended.