Total serum IgE level influences oral food challenge tests for IgE‐mediated food allergies

Abstract

Probability curves predicting oral food challenge test (OFC) results based on specific IgE levels are widely used to prevent serious allergic reactions. Although several confounding factors are known to affect probability curves, the main factors that affect OFC outcomes are currently unclear. We hypothesized that an increased total IgE level would reduce allergic reactivity. Medical records of 337 and 266 patients who underwent OFCs for 3.5 g boiled hen's egg white and 3.1 ml raw cow's milk, respectively, were examined retrospectively. We subdivided the patients into three groups based on total IgE levels and age by percentile (<25th, 25-75th, and >75th percentiles), and logistic regression analyses were performed on each group. Patients with higher total IgE levels were significantly less responsive. In addition, age did not significantly affect the OFC results. Therefore, total IgE levels should be taken into account when predicting OFC results based on food-specific IgE levels.

Safety and feasibility of heated egg yolk challenge for children with egg allergies

“…After our multivariate analyses were adjusted by statistically significant patient factors, total IgE was no longer significant. Low total IgE levels were reported as a risk factor for positive OFC in milk and whole‐egg OFC , in contrast with our findings for heated egg yolk OFC.…”

Ovalbumin‐specific IgE/total IgE ratio improves the prediction of tolerance development in egg‐allergic children aged ≥5 years

“…Our observation that egg‐tolerant (as opposed to egg‐allergic) individuals have higher total IgE levels, which correlate strongly with sIgE, supports the hypothesis that higher total IgE titres might contribute to elevated but clinically irrelevant sIgE levels. In agreement, in a recent study, children with the highest total IgE levels (>75th centile) were less responsive in challenges to cow's milk and egg than those with lower total IgE, even for similar values of sIgE . Federly et al.…”

“…Total IgE might cause artefactual elevation of sIgE levels, possibly leading to misdiagnosis of food allergy. Although a study published 10 years ago reported that the egg‐sIgE/total IgE ratio was not superior to sIgE alone in young children with suspected egg allergy , more recent evidence suggests that total IgE influences allergen‐sIgE levels and challenge outcome . Accordingly, the sIgE/total IgE ratio was found to have better diagnostic performance than sIgE alone for persistent food allergens – particularly for nuts .…”

Elevated total serum immunoglobulin E (>1000 IU/mL): implications?

“…However, a diagnosis of allergic rhinitis is best supported by the detection of specific IgE to allergens relevant to the clinical history. Third, in patients with food allergies, the ratio of allergen‐specific IgE to total serum IgE has predictive value for outcomes of oral food challenges …”