Abstract
Cathelicidins are a group of antimicrobial peptides with a wide range of functions including immunomodulation, chemoattraction, angiogenesis and antimicrobial effects. LL-37 is the active form of the only known human example of a cathelicidin, HCAP-18. It is induced by the local action of 1,25-OH vitamin D. LL37 is expressed by many different cells including lung epithelial cells, neutrophils and other immune cells. We have shown that patients with severe vitamin D deficiency have an increased risk of Acute Lung Injury post-oesophagectomy and hypothesized that this may be related to the effects of vitamin D on LL37.
Methods: Plasma levels of LL37 were determined by ELISA in a cohort of patients with Acute Lung Injury and in a cohort of patients at risk of Acute Lung Injury due to undergo oesophagectomy.
Results: Average pre-operative plasma LL37 levels in the oesophagectomy cohort were 117.2ng/ml and post operative levels are significantly lower (p=0.027, paired t test). In our ALI cohort, median levels of LL37 on day 0 lower than normal levels (p=0.017). LL37 levels correlate with vitamin D status, however, preoperative LL37 levels did not predict Acute Lung Injury.
Conclusion: LL37 levels are lower than normal in patients with Acute Lung Injury and fall perioperatively in patients undergoing oesophagectomy. The mechanism underlying this is unclear and requires further evaluation, but may be related to vitamin D deficiency in these patients.
- © 2011 ERS
