Circulating levels of 25-hydroxyvitamin D and human cathelicidin in healthy adults.

摘要

To the Editor: Cathelicidins are a class of widely conserved antimicrobial peptides produced by essentially all mammalian species as part of the innate immune system. They have broad activity against both gram-positive and gram-negative bacteria and have additional effects, including neutralizing LPS, stimulating leukocyte che-motaxis, and promoting angiogenesis. There is only 1 known cathelicidin in humans. Although it is found in the secondary granules of neutrophils and other leukocyte populations and a range of squamous epithelia, including the skin, airways, mouth, and intestine, it also circulates at high levels in the plasma. Impairment in cathelicidin or other antimicrobial peptides has been linked to increased susceptibility to and severity of infection, whereas overexpression of cathelicidin confers protection against sepsis in animal models. Patients with the lowest circulating levels of cathelicidin undergoing dialysis are at a greater than 2-fold increased risk of death of infectious causes.