Clinical & Experimental Allergy

Assessment of oxidant stress in allergic asthma by measurement of the major urinary metabolite of F2-isoprostane, 15-F2t-IsoP (8-iso-PGF)

Authors


Ryszard Dworski, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University, T-1217 MCN, Nashville, TN 37232–2650, USA. E-mail: ryszard.dworski@mcmail.vanderbilt.edu

Abstract

Asthma is a chronic inflammatory disease of the airways which may involve an oxidant injury to the lung. Assessment of oxidant stress is difficult in vivo, but measurement of F2-isoprostanes (F2-IsoPs), free radical-catalysed products of arachidonic acid, appears to offer a reliable approach for quantitative measurement of oxidative stress status in vivo. We have recently developed a mass spectrometric assay for 2,3-dinor-5,6-dihydro-15-F2t-IsoP (15-F2t-IsoP-M), the major urinary metabolite of the F2-IsoP, 15-F2t-IsoP (8-iso-PGF2a). Measurement of the urinary excretion of this metabolite offers a reliable index of oxidative stress status in vivo that has advantages over measuring unmetabolized F2-IsoPs in urine and plasma.

To assess the occurrence of oxidative stress in patients with atopic asthma following allergen exposure in vivo by measuring the urinary excretion of 15-F2t-IsoP-M.

Analysis of 15-F2t-IsoP-M by GC-NICI-MS in nine mild atopic asthmatics following inhaled allergen provocation and four asthmatic subjects after inhaled challenge with methacholine.

Urinary excretion of 15-F2t-IsoP-M increased at 2 h after allergen challenge and remained significantly elevated in all urine collections during the subsequent 8-h period of the study compared to the baseline value (anova, and Student–Newman–Keuls multiple comparisons test). No increase in the urinary excretion of 15-F2t-IsoP-M occurred after inhalation of methacholine.

Allergen challenge causes an oxidant injury in human atopic asthmatics. 15-F2t-IsoP-M is a valuable marker of oxidant stress in vivo.

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