Asthma related to Alternaria sensitization: an analysis of skin-test and serum-specific IgE efficiency based on the bronchial provocation test
Article first published online: 24 NOV 2010
© 2010 Blackwell Publishing Ltd
Clinical & Experimental Allergy
Volume 41, Issue 5, pages 649–656, May 2011
How to Cite
Fernández, C., Bevilacqua, E., Fernández, N., Gajate, P., de la Cámara, A. G., Garcimartín, M., Vives, R. and Rodríguez, J. (2011), Asthma related to Alternaria sensitization: an analysis of skin-test and serum-specific IgE efficiency based on the bronchial provocation test. Clinical & Experimental Allergy, 41: 649–656. doi: 10.1111/j.1365-2222.2010.03645.x
- Issue published online: 13 APR 2011
- Article first published online: 24 NOV 2010
- Submitted 30 October 2009; revised 3 September 2010; accepted 27 September 2010.
- allergic asthma;
- alternaria serum-specific IgE;
- alternaria skin tests;
- logistic regression;
- ROC curve
Background It is difficult to find a causal relationship between exposure to Alternaria spores and the development of asthma symptoms in sensitized individuals due to the complexity of clinical situations in which positive diagnostic tests are often found.
Objective To analyse the diagnostic efficiency of skin testing (ST) and serum-specific IgE to Alternaria, based on the results of a bronchial specific challenge with Alternaria extracts.
Methods Seventy-four asthmatic patients sensitized to Alternaria underwent a specific bronchial challenge with this mould. Skin-testing weal sizes, serum-specific IgE values (CAP-system) and bronchial challenge results were analysed by receiver operating characteristics curves (ROC curves) and logistic regression. The sensitivity, specificity, positive and negative predictive values were calculated for different cut-off points.
Results Bronchial challenges to Alternaria elicited a positive result in 45 patients (61%). Skin prick testing almost perfectly predicted the outcome of bronchoprovocation tests (area under the ROC curve of 0.957), whereas intradermal skin testing had moderate efficacy. A negative result for skin prick test (SPT) showed a 4% probability of a positive bronchial challenge in the logistic regression analysis. However, weals around 5.5 mm in diameter had 90% probability of a positive challenge. Quantification of serum-specific IgE correctly classified 86% of the cases. In the logistic regression analysis, a CAP value 16 kUA/L predicted a positive bronchial challenge result with 99% accuracy, whereas for a CAP value <0.35 kUA/L, this probability was 33%.
Conclusions and Clinical Relevance Most asthmatic patients with positive SPT results to Alternaria would have a positive bronchial challenge. As atmospheric mould levels may vary significantly with the weather conditions, sensitized patients should be instructed on the risk situations, environmental control measures and the importance of correct medication compliance. Immunotherapy with Alternaria could also be taken into account as a valid therapeutic option.
Cite this as: C. Fernández, E. Bevilacqua, N. Fernández, P. Gajate, A. G. de la Cámara, M. Garcimartín, R. Vives and J. Rodríguez, Clinical & Experimental Allergy, 2011 (41) 649–656.