Neutrophilia and hyperamylasemia in patients with immediate food allergy

BACKGROUND: Presently, little is known about the laboratory data several hours after oral food challenge (OFC) in patients with immunoglobulin (Ig)E‐mediated immediate food allergy (FA). METHODS: One hundred and twelve subjects who underwent OFC at the present institute between 1 June 2016 and 31 March 2018, were enrolled in this study. Changes in laboratory data several hours after OFC were examined. RESULTS: OFC was positive in 76 patients and negative in 36. Increase in absolute neutrophil count (ANC) was significantly higher in OFC‐positive than in OFC‐negative subjects (median, 2,306/μL vs 637/μL; P < 0.00001). On multivariate regression analysis, a significant correlation was seen between neutrophilia and the development of gastrointestinal symptoms (t = 3.63; P < 0.001). Serum interleukin‐6 increased in 43.8% of the patients with marked neutrophilia and had a significant positive correlation with ANC (r = 0.64; P < 0.001). Serum amylase increased in 33.3% of the OFC‐positive patients and was >100 U/L (median, 642 U/L) in five patients in whom serum lipase also increased markedly (1,197 U/L). There was a significant negative correlation between increase in serum amylase and decrease in absolute eosinophil count (r = −0.36, P < 0.01). CONCLUSIONS: Marked neutrophilia was seen after OFC in patients with immediate FA presenting gastrointestinal symptoms, which may provide an insight into the relationship between symptoms and laboratory data. A considerable increase in serum amylase after OFC was also seen in patients with immediate FA, suggesting that the pancreas is a target organ for immediate FA.