[The clinical value of China Savin pollen extract used for skin prick test].

ABSTRACT

Objective:The aim of this study is to evaluate the effectiveness and safety of China Savin pollen extract which was used for skin prick test (SPT) in the diagnosis of China Savin pollen allergy. Method:Patients with diagnosis of allergic diseases were collected from Allergy Department of Peking Union Medical College Hospital. All patients were given SPT with China Savin pollen extract, and the mean wheal diameter (MWD) was measured after 15 minutes. Receiver operating characteristic curve (ROC) analysis was performed based on the results of serum specific immunoglobulin E (sIgE). The effectiveness of SPT in the diagnosis of China Savin pollen allergy was evaluated under different diagnostic cutoff values. Adverse events were also recorded to evaluate the safety. Result:A total of 1 029 patients were enrolled in this study without drop out case. There were 1 007 patients in full analysis set (FAS) and 765 patients in per protocol analysis set (PPS). The elimination rate was 25.66%. The area under the ROC curve of FAS is 0.814 (95%CI 0.788-0.839); which of PPS is 0.829 (95%CI 0.801-0.857). Based on the ROC curve of PPS, the optimal and the 95% specificity diagnostic cutoff values of MWD were 3.25 mm and 4.75 mm respectively. Based on different diagnostic cutoff value (3.00, 3.25 and 4.75 mm), the sensitivities of SPT with China Savin pollen extract were 0.740 0 (95%CI 0.701 6-0.778 4), 0.700 (95%CI 0.659 8-0.740 2) and 0.532 (95%CI 0.488 3-0.575 7) respectively, whereas the specificity was gradually increased in sequence, which was 0.769 8 (95%CI 0.719 1-0.820 5), 0.826 4 (95%CI 0.780 8-0.872 0) and 0.950 9 (95%CI 0.924 9-0.976 9) respectively. There were 7 adverse events observed among 6 patients (rate 0.583%, 6/1 029). The manifestation was mild. There was no severe adverse event. Conclusion:SPT with China Savin pollen extract is an effective and safe tool for the diagnosis of China Savin pollen allergy. The effectiveness of diagnosis could be improved based on integration of medical history and different diagnostic threshold values of SPT.