In vitro diagnosis of allergy: how to interpret IgE antibody results in clinical practice

National Institute of Environmental Medicine, Centre for Allergy Research, Karolinska Institute, Stockholm, Sweden.
Primary Care Respiratory Journal (Impact Factor: 2.5). 09/2006; 15(4):228-36. DOI: 10.1016/j.pcrj.2006.05.004
Source: PubMed


The basis of any diagnosis of allergy requires a good history and examination, which should then provide a certain degree of confidence as to whether or not allergy is present. However, the diagnosis cannot be confirmed on the basis of symptoms alone, because both allergic and non-allergic conditions can present with similar symptoms. Based on prevalence figures, about half of the patients presenting with allergic symptoms in primary care may be non-allergic. Therefore, allergy testing in the form of specific IgE (sIgE) measurement and/or skin prick testing is an invaluable aid in demonstrating both the presence and severity of such an allergy. The usefulness of such tests extends beyond just the positive or negative result. Often, more information can be gleaned by using the test results in a form of a continuous variable in order to determine the likelihood that allergy can be attributed as an explanation for patients' symptoms and disease. In this review, we describe the rationale for utilising specific IgE antibody tests in diagnosing allergy. Furthermore, to optimize the information gained from allergy testing, we describe how to employ one particular well-validated IgE testing system for determining the likelihood that an individual patient's disease can be attributed to allergy.

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    • "Likewise, it is important to be able to exclude allergy from other reasons for the symptoms. In particular, the presence of allergy and elevated IgE antibody levels represents a risk for acute and complicating reactions over time [14]. "
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    ABSTRACT: Background Allergy is a serious problem affecting approximately 1 of 4 individuals. The symptoms with and without allergy etiology are often difficult to distinguish from each other without using an IgE antibody test. The aim of this study was to investigate the performance of a new point-of-care (POC) test for IgE antibodies to relevant allergens in Europe. Methods IgE antibodies from children and adults with allergies recruited from allergy clinics in Sweden and Spain were analyzed for 10 allergens, suitable for the age groups, using the new POC test and ImmunoCAP laboratory test. The IgE antibody level best discriminating between positive and negative results (the cutoff point) for the different allergens of the POC test and the efficacy of the POC and the ImmunoCAP laboratory tests for diagnosing allergy compared with that of clinical diagnosis were investigated. Results The estimated cutoffs for the different allergens in the POC test ranged from 0.70 to 2.56 kUA/L. Taking into account all positive allergen results in a given patient, the POC test could identify 95% of the patients with allergies. Seventy-eight percent of the allergen-specific physicians' diagnoses were identified and 97% of the negative ones. Most allergens exhibited good performance, identifying about 80% of clinically relevant cases. However, dog, mugwort, and wall pellitory would benefit from improvement. Conclusions The POC test will be a valuable adjunct in the identification or exclusion of patients with allergies and their most likely offending allergens, both in specialist and general care settings.
    World Allergy Organization Journal 07/2009; 2(7):138-143. DOI:10.1097/WOX.0b013e3181aed85c
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    • "Availability of specific IgE (sIgE) tests within primary care varies considerably in different parts of the world. As described in the review [7] and the editorial [6], there are situations when these tests assist in diagnosing allergy in addition to, or in place of, skin prick testing. "

    Primary Care Respiratory Journal 05/2006; 15(2):75-7. DOI:10.1016/j.pcrj.2006.02.001 · 2.50 Impact Factor
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    • "Other non-allergic conditions are unspecific bronchial hyperreactivity and food intolerance. The distinctions between allergic and non-allergic conditions are difficult to make in clinical practice (Ahlstedt & Murray, 2006), although the allergic reaction frequently manifests itself early in life and is often more severe and persistent than the non-allergic reaction (Sampson, 1999). It is particularly difficult to differentiate symptoms from the gastrointestinal tract, which is the area that is most frequently affected in food allergy and food intolerance (Sampson, 1999). "
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    ABSTRACT: ABSTRACT The overall objective of this thesis is to extend the knowledge and deepen the understanding of care-givers management of child allergy, especially of suspected food allergy. This is done by describing and exploring how parents with children who have exclusion diets at school discover and responds to their children’s allergy-related problems. The first study focuses on the whole group of children (n 230) with special diets at school from the viewpoint of parents’ knowledge and management of the children’s problems. It addresses questions regarding (1) whether or not the children have had contact with health care, (2) whether or not they were diagnosed with food allergy, (3) to what extent they had other allergies, (4) what characterized their food-related symptoms, (5) if these symptoms were consistent with the clinical experience of food allergy (6) and any differences in parents’ reports of the extent of children’s food-related problems in regard to whether they had sought health care or not. The results showed that the majority of parents had consulted doctors for their children’s problems, and most children had been diagnosed by a doctor. Most children also had other allergies or asthma in addition to their food-related problems. The children’s food-related problems were consistent with the clinical experience of food allergy. Parents who had sought medical aid for their children’s problems,described more,extensive and,potentially life-threatening (e.g. anaphylactic) symptoms than did the parents who had not sought professional help. Overall, the characteristics of children’s symptoms,were similar in both groups and were considerable enough to explain why they avoided certain foods and had exclusion diets at school. The second study addresses the question of how parents discovered developing bodily symptoms
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