Monday, 5 December 2011: 14:00 - 14:15
Xcaret (Cancún Center)
Gregory Hawkins, PhD
,
Center for Genomics and Personalized Medicine Research, Wake Forest University School of Medicine, Winston Salem, NC
Mac Robinson, PhD
,
Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston Salem, NC
Wendy Moore, MD
,
Center for Genomics and Personalized Medicine Research, Wake Forest University School of Medicine, Winston Salem, NC
Annette Hastie, PhD
,
Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston Salem, NC
Rodolfo Pascual, MD
,
Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston Salem, NC
Stephen P. Peters, MD, PhD
,
Center for Genomics and Personalized Medicine Research, Wake Forest University Health Sciences, Winston-Salem, NC
Deborah Meyers, PhD
,
Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston Salem, NC
Eugene R. Bleecker, MD
,
Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston Salem, NC
Background: : Interleukin 6 (IL6) belongs to a family of cytokines with both pro- and anti-inflammatory properties. The functional relationship between IL6 signaling and airway disease has not be well characterized; however, IL6 expression is increased during lung inflammation and injury. In this study, serum IL6 and soluble IL6R levels were assessed in non-Hispanic whites with asthma from the Severe Asthma Research Program. Correlations between serum IL6 and IL6R levels, lung function, phenotypic asthma clusters, and asthma severity were evaluated.
Methods: Serum IL6 and soluble IL6R was measured in 149 subjects with mild to severe asthma. Serum sIL6R levels were measured using the sIL-6R DuoSet (R&D Systems, Minneapolis, MN) ELISA kit and reported as ng/ml. Serum IL6 measurements were determined using the IL-6 ELISA kit (R&D Systems, Minneapolis, MN) and reported as pg/ml. Serum IL6 and sIL6R measurements were log transformed to normalize distribution. The continuous variables analyzed included: % predicted FEV1 [ppFEV1], % predicted FVC [ppFVC], and FEV1/FVC. Serum samples were collected at Wake Forest. Phenotypic asthma clusters were derived as previously described (Am J Respir Crit Care Med. 2010 181(4):315-23).
Results: Elevated serum IL6 was associated with lower ppFEV1 (p = 0.02) and lower ppFVC (p = 0.003), while elevated serum soluble IL6R was associated with lower ppFEV1 (p = 0.02) and lower ppFVC (p = 0.008). Increasing trends in serum IL6 were observed in atopic asthma Clusters 2 and 4 and the later onset fixed airways obstruction Cluster 5. The highest IL6 serum levels were observed in Cluster 3 characterized has having late onset asthma and elevated BMI. Serum IL6 levels were elevated in subjects with severe asthma (log IL6 = 0.33; N = 25) compared to subjects with mild/moderate asthma (log IL6 = 0.16; N = 69).
Conclusions: Serum IL6 and sIL6R levels are elevated in non-Hispanic white asthma subjects with lower lung function. Serum IL6 and sIL6R are potentially important biomarkers that may distinguish between non-severe and severe asthma and between atopic asthma Clusters.
