دانلود رایگان مقاله توسعه یک مدل پیش بینی واکنش شدید در چالش های تخم مرغ آب پز

abstract

Background: We have proposed a new scoring system (Anaphylaxis SCoring Aichi: ASCA) for a quantitative evaluation of the anaphylactic reaction that is observed in an oral food challenge (OFC). Furthermore, the TS/Pro (Total Score of ASCA/cumulative protein dose) can be a marker to represent the overall severity of a food allergy. We aimed to develop a prediction model for a severe allergic reaction that is provoked in a boiled egg white challenge. Methods: We used two separate datasets to develop and validate the prediction model, respectively. The development dataset included 198 OFCs, that tested positive. The validation dataset prospectively included 140 consecutive OFCs, irrespective of the result. A ‘severe reaction’ was defined as a TS/Pro higher than 31 (the median score of the development dataset). A multivariate logistic regression analysis was performed to identify the factors associated with a severe reaction and develop the prediction model. Results: The following four factors were independently associated with a severe reaction: ovomucoid specific IgE class (OM-sIgE: 0e6), aged 5 years or over, a complete avoidance of egg, and a total IgE < 1000 IU/mL. Based on these factors, we made a simple scoring prediction model. The model showed good discrimination in a receiver operating characteristic analysis; area under the curve (AUC) ¼ 0.84 in development dataset, AUC ¼ 0.85 in validation dataset. The prediction model signifi- cantly improved the AUC in both datasets compared to OM-sIgE alone. Conclusions: This simple scoring prediction model was useful for avoiding risky OFC.

Discussion

We have developed the original severity score of allergic symptoms, named ASCA, and defined the overall severity indicator ‘TS/Pro’. By using this index, we identified the factors associated with severe results (low threshold and high symptom scores) in OFCs to boiled egg white. Furthermore, we developed a simple prediction model for a severe allergic reaction in OFCs. The model was constructed using the OFC positive dataset and the discriminative ability of this model was validated in another dataset including challenge-negative cases. In the present study, OFCs were performed even for patients with a high probability for positive results, unless a recent anaphylaxis event was experienced with a small amount of allergen exposure. We aimed to find a safe dose of allergen ingestion, even among the challenge-positive patients, according to the basic strategy written in the Japanese guidelines.3 However, we needed to avoid dangerous and ineffective challenges with a low probability of finding the safe dose of allergen ingestion. For the purpose of predicting such severe cases, we analyzed factors associated with severe cases and developed prediction model. We included only positive OFCs (60.7% of the total OFCs) to develop the prediction model. This was because the final dose was limited to a small amount for the safety of severely allergic patients and the true TS/Pro might not be zero if a larger amount was applied.