Background: Assessment of sIge level, total IgE level and eosinophils percentage are the common markers used for diagnosis of atopic and allergic patients. This study aimed to assess the diagnostic accuracy of allergy markers included sIgE, total IgE testing and eosinophils percentage in the diagnosis of allergic diseases, in reference to final clinical diagnosis.
Materials and Methods: This retrospective study included 130 patients were randomly selected from the electronic records of patients suspected for allergy based on a history of significant respiratory or skin reaction and live in Jeddah city. Total IgE level was assessed using Unicap 100, while the assessment of specific IgE was conducted by the ImmunoCAP technology. The pooled analysis was done to calculate clinical sensitivity, specificity, positive and negative predictive values for the studied allergy markers.
Results: The sensitivity and specificity of sIgE assay were found to be 87% and 100% in comparison to 79% and 93% of total IgE assay and 70% and 100% in eosinophils percentage respectively. In addition, positive and negative predictive values of sIgE were found 100% and 69.8% in comparison to 97.5% and 57.1% of total IgE respectively. While positive and negative predictive values of eosinophils percentage were found 100% and 50% respectively.
Conclusions: In conclusion, the clinical sensitivity was very good in sIgE, good in total IgE but fair in eosinophils percentage, while the clinical specificity was excellent in all of these allergy markers. Positive predictive value was excellent in all allergy markers, but negative predictive value ranged from fair value in sIgE to poor value in eosinophils percentage.
Allergy; asthma; IgE; eosinophils; sensitivity; specificity.