Human antimicrobial proteins in ear wax.

The external auditory canal is vulnerable to bacterial infections, but little is known about thechemical compositions of ear wax regarding antimicrobial peptides. We, therefore, studied the proteinconcentrations of ten well-known human antimicrobial peptides from ear wax.Twenty ear wax samples from healthy individuals were analysed using enzyme-linked immunosorbent assay (ELISA) to determine theprotein concentrations of the antimicrobial peptides hBD1-3, lactoferrin, LL-37, BPI, hSLPI and HNP1-3. All ten antimicrobial peptides are present in ear wax. Some of these proteins seem to be merelycell-bound in ear wax. Antimicrobial peptides in ear wax prevent bacteria and fungi from causing infections inthe external auditory canal. The role and importance of these proteins for the blind-ending ear externalcanal is discussed. If this local defence system fails, infections of the external auditory canal may result.The knowledge about the presence of antimicrobial peptides in cerumen may lead to new concepts ofthe local treatment of external auditory canal diseases in the future.