The present invention relates to the identification of certain biomarkers for use in identifying patients who have, or are likely to develop an IL-33 mediated disease or disorder and who are more likely to respond to therapy with an IL-33 antagonist. The invention also relates to methods of treatment of an IL-33-mediated disease or disorder in a patient by administering an IL-33 antagonist to the patient in need thereof and monitoring the effectiveness of therapy using the biomarkers described herein. Also provided are methods for decreasing the level of at least one biomarker in a subject suffering from an IL-33-mediated disease or disorder, and methods for treating such diseases or disorders according to the expression levels of one or more biomarkers. The methods of the present invention comprise administering to a subject in need thereof a pharmaceutical composition comprising an interleukin-33 antagonist.