PT  - JOURNAL ARTICLE
AU  - Carlos Antonio Amado
AU  - Javier Villuela
AU  - Mayte García-Unzueta
AU  - Juan José Ruiz-Cubillan
AU  - Alejandro Daly
AU  - Beatriz Abascal
AU  - Diego Ferrer
AU  - Francisca Santos
AU  - David Iturbe
AU  - Ramón Agüero
TI  - LL-37 is produced intrapleurally in infectious pleural effusion
DP  - 2012 Sep 01
TA  - European Respiratory Journal
PG  - P2520
VI  - 40
IP  - Suppl 56
4099  - http://erj.ersjournals.com/content/40/Suppl_56/P2520.short
4100  - http://erj.ersjournals.com/content/40/Suppl_56/P2520.full
SO  - Eur Respir J2012 Sep 01; 40
AB  - LL-37 is an antimicrobial peptide produced by neutrophils, respiratory epithelial and mesothelial cells that has been studied for its broad spectrum activity against microorganisms. It also recruits inflammatory cells and promotes immune responses. It has never been measured in pleural fluid.Aims And ObjectivesThe objective of our study is to measure the pleural and serum levels of LL-37 in pleural effusion patients, and to compare these levels and the pleural-to-serum LL-37 ratio among pleural fluids of three frequent etiologies: infectious, malignant and congestive heart failure(CHF).MethodsWe obtained 42 pleural effusions and divided them into 3 diagnostic categories. LL-37 was measured in the pleural fluid and serum of 23 infectious effusions, 10 malignant effusions and 9 CHF effusions by ELISA. Statistical analyses were performed using software SPSS 17.0.ResultsResults are presented: mean +/- Std. Deviation(median, minimun-maximun).Pleural Fluid LL-37 levels: Infectious 3.77±4.81 ng/ml (1.64, 0.38-19.4) malignant 2.58±4.17 (0.87, 0.09-135), CHF 1.59±1.02 (0.99, 0.47-3.3) (p= 0.4).Serum LL-37 levels: Infectious 2.09±3.42 ng/ml(0.98, 0.06-16.35) malignant 3.44±4.3(1.19, 0.17-12.6), CHF 3.44±3.02(2.6, 0.71-10.3)(p=0.13)Pleural fluid-to-Serum LL-37 ratio levels: Infectious 1.33±1.88(1.29, 100-0.43) malignant 0.60±0.92(0.72, 1.11-0.21), CHF 0.46±0.93(0.44, 1.12-0.24)(p< 0.001. Infectious vs malignant p=0.002, infectious vs CHF p<0.001, malignant vs CHF not significant).ConclusionsPleural fluid-to-Serum LL-37 ratios are significantly elevated in infectious pleural effusions in comparison with malignant or CHF pleural effusions, suggesting that LL-37 is actively produced intrapleurally in infectious effusions.