Real world use of peanut component testing among children in the Chicago metropolitan area.

Peanut component tests (PCT) have become important in the evaluation of peanut allergy. There remains a paucity of research across the United States in investigating the utility of PCT in clinical practice in conjunction with current standards of care. The primary aims were to evaluate the performance and sensitization patterns of PCT in clinical practice when first available at our institution. We performed a retrospective chart review of 184 children with PCT and oral food challenge (OFC) results between 2012 and 2017. Simple logistic regression models assessed the associations between PCT and OFC outcomes. Receiver operator characteristic curves were constructed, and a predicted probability curve was derived for Ara h2. The median (interquartile range [IQR]) age at OFC was 4 years (2-7 years), and 111 patients (60%) were boys. Ara h 2 was the most commonly sensitized PCT. Sixty-one patients (33%) reacted at OFC. Ara h 2 specific immunoglobulin E (sIgE) ≥ 0.35 kU/L was associated with increased odds of reacting at OFC (odds ratio 5.91 95% confidence interval, 2.93-11.89; < 0.001); however, 19 patients (37%) positive for Ara h 2 did not react. Ara h 2 sIgE of 0.49 kU/L and 4.58 kU/L were associated with 50% and 90% probability, respectively, of reacting at OFC. Among those sensitized only to Ara h 8 or 9 ( = 21), 86% had no reaction. There was no statistically significant association with polysensitization to Ara h 1, 2, and 3, and peanut OFC outcome. Although the Ara h 2 sIgE value was associated with clinical reactivity, a significant proportion of the patients sensitized to Ara h 2 tolerated peanut. OFC remains an important tool in the evaluation of peanut allergy.