Cow milk protein allergy mimics in infancy

Table 6 Some of the biomarkers that are associated with the severity and persistence of cow milk protein allergy

Biomarker	Type	Associated with severity	Associated with persistence	Comments
SPT	Clinical test	≥ 8 mm indicates high reaction risk during OFC	Related to milk allergy persistence	Predictive of OFC outcomes, useful for identifying high-risk patients
EPT	Clinical test	High risk of anaphylaxis during food challenges	Marker for milk allergy persistence	Described as more useful than SPT for identifying severe milk allergy risk
sIgE	Serum biomarker	Severe allergic reactions in peanut and milk	Higher levels linked with persistent allergies	sIgE cutoffs can predict OFC outcomes
BAT	Cellular biomarker	High CD63 ratio linked to severe reactions	Associated with severe clinical milk reactivity	High proportions of activated basophils indicate severe allergic reactions
Cytokines (interleukin-13, interleukin-10)	Immune biomarker	Higher levels during allergic inflammation	Linked to persistent milk and egg allergies	Elevated in both milk and egg allergy studies, indicating immune dysregulation
Calprotectin	Fecal biomarker	Not specified	Associated with persistent gastrointestinal inflammation	Useful for differentiating non-IgE-mediated allergies from other GI conditions
EDN	Fecal biomarker	Not specified	Associated with persistent gastrointestinal inflammation	Indicates eosinophilic inflammation in the gastrointestinal tract

This table illustrates the growing complexity of allergy diagnostics and highlights emerging biomarkers that may improve the differentiation and management of cow milk protein allergy. SPT: Skin prick tests; OFC: Oral food challenge; EPT: Endpoint test; sIgE: Specific IgE; BAT: Basophil activation test; EDN: Eosinophil-derived neurotoxin.