Monitoring of peanut-allergic patients with peanut-specific IgE.
Peanut allergy affects approximately 1% of the population. Double-blind placebo-controlled food challenges are gold standard for diagnosis. Serum peanut-specific IgE (PN-IgE) is used in clinical practice as an additional diagnostic and monitoring tool. The purpose of this study was to characterize the clinical features of a peanut-allergic patient's cohort and determine the optimum frequency of measuring PN-IgE to predict the outcome of future peanut challenges. Retrospective chart review was performed of peanut-allergic patients followed up and serially tested for PN-IgE with a qualitative antibody fluorescent-enzyme immunoassay performed at the Immunology Laboratory, London Health Sciences Center, from 1997 to 2004. One hundred eighteen patients (median age at first reaction to peanut, 1.5 years; median baseline PN-IgE, 18.75) were reviewed. Younger age at first reaction and first PN-IgE measurement predicted slower decline of PN-IgE values (p < 0.001 and p = 0.044). At 2 and 5 years post-initial measurement, 12.9 and 66%, respectively, of all patients had a significant decrease of PN-IgE values. Twenty percent of the patients experienced elevation of PN-IgE levels during follow-up. For most patients with significant history of reaction to peanuts and positive skin-prick test, it is probably adequate to measure serum PN-IgE levels every 3-5 years to screen for development of tolerance and predict the outcome of future peanut challenges. More frequent measurements might be considered in older patients with lower initial PN-IgE levels.
Borici-Mazi
Rozita
R
Division of Allergy and Clinical Immunology, Department of Medicine, University of Western Ontario, London, Canada. rboricim@uwo.ca
Mazza
Jorge A
JA
Moote
David W
DW
Payton
Keith B
KB
D000293:Adolescent; D010367:Arachis / Q000009:adverse effects; D001249:Asthma / Q000150:complications / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018985:Epitopes, B-Lymphocyte / Q000097:blood / Q000737:chemistry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood* / Q000737:chemistry / Q000276:immunology*; D007223:Infant; D008297:Male; D018716:Molecular Mimicry / Q000276:immunology*; D008991:Monitoring, Physiologic; D021183:Peanut Hypersensitivity / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D011237:Predictive Value of Tests; D012220:Rhinitis / Q000150:complications / Q000276:immunology
D018985:Epitopes, B-Lymphocyte; D007073:Immunoglobulin E