Methods: A total of 1945 patients with allergic symptoms underwent MAST and serum total IgE tests. 39 panels were evaluated in MAST and allergens with results greater than class 2(≥0.7 IU/mL) in considered as positive. To analyze the results of serum total IgE with clinical symptoms, Total nasal score(TNS) was evaluated as sum of 4 nasal symptoms(rhinorrhea, nasal obstruction, sneezing and itching sense).
The patients were divided into high(≥100 IU/mL) and low(<100 IU/mL) groups of total serum IgE level and the positive rates and number of positive allergen specific IgEs were evaluated in each group. Furthermore, we calculated cut off value of serum total IgE to predict positive allergen specific IgE.
Results : Nasal obstruction turned out to be the most common symptom (65.6%). Total score of TNS showed significant correlation with serum total IgE quantity. High total serum IgE group showed significantly higher positive rates and number of positive allergen specific IgEs on MAST. (p<0.05). Number of allergen specific IgEs showed good correlation with serum total IgE(r=0.521, p<0.05).
With use of ROC curve, cut off value of serum total IgE was computed as 108 IU/mL(sensitivity 72.42%, specificity 72.87%). Due to low sensitivity, we analyzed positive predictive value of serum total IgE divided into each group. We suggested 50 IU/mL is more predictable.
Conclusions: Serum total IgE appears to be useful in predicting positive results of allergen specific IgEs in MAST. Also, serum total IgE with level of 50 IU/mL turned out to be most reliable to recommend MAST.