Low serum adrenic acid levels in infants and subsequent food-induced anaphylaxis

Abstract

BackgroundThe dietary fat hypothesis links increases in allergic diseases to reduced consumption of n-3 polyunsaturated fatty acids (PUFAs) from fish, e.g., eicosapentaenoic acid (EPA), and increased intake of n-6 PUFAs from vegetable oils, e.g., arachidonic acid (AA). ObjectiveBuilding upon the 'fat hypothesis', we aimed to investigate the association between 24 types of serum fatty acid levels in infants and the risk of subsequent food-induced anaphylaxis (FIA) by 2 years of age as the primary outcome. MethodsThis study was conducted as a prespecified supplemental analysis within the ABC randomized clinical trial. We measured levels of 24 fatty acids in residual serum samples collected from 268 infants at 5-6 months of age using gas chromatography-mass spectrometry. ResultsAmong the 258 infants, 58 exhibited immediate-type food allergies, while 200 showed no food allergy (NFA). Of the 58 infants, 12 were diagnosed with FIA, while the remaining 46 had non-anaphylactic food allergy (NAFA). Unexpectedly, among the 24 fatty acids, only adrenic acid (AdA), also known as docosatetraenoic acid, which is one of the n-6 PUFAs, showed significantly lower levels in infants with FIA (median [IQR] (wt.%): 0.16 [0.14-0.17]), compared to those with NFA (0.19 [0.17-0.21]) (P=.0007). In contrast, AdA levels in infants with NAFA were 0.19 [0.16-0.21] (wt.%), which did not differ significantly from infants with NFA (P=.69). ConclusionThis study generated a hypothesis suggesting that infants with low serum AdA levels might be at greater risk of subsequent FIA. This unexpected result warrants further investigation.