Eosinophilic esophagitis (EE) is an emerging disorder with a poorly understood pathogenesis. In order to define disease mechanisms, we took an empirical approach analyzing esophageal tissue by a genome-wide microarray expression analysis. EE patients had a striking transcript signature involving 1% of the human genome that was remarkably conserved across sex, age, and allergic status and was distinct from that associated with non-EE chronic esophagitis. Notably, the gene encoding the eosinophil-specific chemoattractant eotaxin-3 (also known as CCL26) was the most highly induced gene in EE patients compared with its expression level in healthy individuals. Esophageal eotaxin-3 mRNA and protein levels strongly correlated with tissue eosinophilia and mastocytosis. Furthermore, a single-nucleotide polymorphism in the human eotaxin-3 gene was associated with disease susceptibility. Finally, mice deficient in the eotaxin receptor (also known as CCR3) were protected from experimental EE. These results implicate eotaxin-3 as a critical effector molecule for EE and provide insight into disease pathogenesis.
Carine Blanchard, Ning Wang, Keith F. Stringer, Anil Mishra, Patricia C. Fulkerson, J. Pablo Abonia, Sean C. Jameson, Cassie Kirby, Michael R. Konikoff, Margaret H. Collins, Mitchell B. Cohen, Rachel Akers, Simon P. Hogan, Amal H. Assa’ad, Philip E. Putnam, Bruce J. Aronow, Marc E. Rothenberg