PT - JOURNAL ARTICLE AU - Alex Yacob AU - Jacquelyn Zirbes AU - Colleen Dunn AU - Roham Zamanian AU - Richard Bland AU - Marlene Rabinovitch AU - Mark Nicolls AU - Carlos Milla TI - Late-breaking abstract: A relative plasma elafin deficiency in children with cystic fibrosis (CF) is associated with pulmonary disease DP - 2014 Sep 01 TA - European Respiratory Journal PG - P1200 VI - 44 IP - Suppl 58 4099 - http://erj.ersjournals.com/content/44/Suppl_58/P1200.short 4100 - http://erj.ersjournals.com/content/44/Suppl_58/P1200.full SO - Eur Respir J2014 Sep 01; 44 AB - Elafin is an inducible potent and selective serine elastase inhibitor with additional anti-inflammatory and anti-microbial properties. We hypothesized that a relative deficiency in circulating Elafin levels in relation to elastase, reflecting an imbalance in anti-elastolytic capacity, will be associated with the severity of lung disease in children with CF. Plasma samples were obtained from 35 children with CF free from exacerbation and compared to a group of 82 healthy individuals. Samples were assayed in duplicate by ELISA for Elafin and elastase concentrations, and the ratio of circulating elastase to Elafin (e:E) was calculated for each subject. Lung disease severity was assessed by forced expiratory volume in 1 second (FEV1). CF patients (17F, 18M) had a mean (SD) age of 12.8 (4) years, a FEV1 Z-score of -1.64 (1.7) and a Body Mass Index (BMI) z-score of 0.12 (0.9); 22% were infected with Pseudomonas, 75% with S. aureus and 8% were co-infected. Elafin levels were significantly lower in the CF patients compared to controls (17.2 vs. 75.4 ng/mL, p<0.001), whereas elastase levels were comparable (80.4 vs. 94.5 ng/mL, p=0.3). Mean e:E ratio in the CF children was 5.9 (3.1), which was significantly higher than the control group at 2.3 (1.8), (p<0.001). FEV1 Z-scores were not correlated with Elafin levels (p=0.4) but inversely correlated with elastase and e:E ratio (p <0.05 for both). Infection status, age or gender did not modify these associations. We conclude that in children with CF a relative deficiency in Elafin as reflected in a high e:E ratio is associated with the severity of lung disease. Elafin replenishment therapy could be a potential effective intervention.