Methacholine and adenosine 5'-monophosphate challenge tests in children with atopic asthma and with nonatopic asthma, and their relationships to blood eosinophil markers

Abstract

Purpose:Though atopic and nonatopic asthma have different clinical manifestations, bronchial hyperresponsiveness (BHR) and airway inflammations are common characteristics of them. We investigated BHR to both methacholine and adenosine 5'-monophosphate (AMP), and their relationships with blood eosinophil markers in nonatopic asthma as well as atopic asthma. Methods:We studied 116 children (82 atopics; 34 nonatopics) with mild to moderate asthma. Methacholine and AMP challenge tests were performed and bronchial responsiveness was expressed as PC20 (provocative concentration causing a 20 percent fall in FEV1); blood eosinopil counts (ETCs) and serum eosinophil cationic protein (ECP) levels were gauged. Results:In atopics, 95.1 percent and 90.2 percent showed hyperreactivity to methacholine (PC20