416 Milk Components as a Tool in Predicting Tolerance in Cow's Milk Allergy

BACKGROUND: One important point in cow's milk allergy (CMA) is to stablish predicitve factors in acquiring tolerance. The aim of this study is to evaluate if a ratio of milk components: alpha-lactalbumin (α), beta-lactoglobulin (β), casein (C) and whole milk (WM) can contribute to predict tolerance development. METHODS: It was a retrospective study that included patients with previous diagnosis of CMA evaluated at 6 years old. CMA was defined as a positive double blind placebo-controlled food challenge, open challenge or confirmed anaphylaxis plus positive specific IgE to cow's milk (higher than 3.5 kU/L or positive skin prick test), and tolerance was defined as acceptance of cow milk without previous symptoms. Specific IgE analysis to WM, α, β, and C were performed through Immunocap (Phadia AB). Ratios of milk components and whole milk (α /WM, β/WM, C/WM) were calculated and compared the results in 2 study groups: tolerant and persistent at 6 years old. Since values from both α /WM and β/WM ratios didn't follow a normal distribution, Mann-Whitney test was used to compare groups. For C/WM ratios, Student's t test was used as values were normally distributed. RESULTS: It included 49 patients (27 male/22 female), 24 tolerant and 25 persistent. Average age of Immunocap test was 2.7 years (SD = 1.4). Comparing the results from 2 groups, persistent and tolerant it was detected: no difference in α /WM (P = 0.055, Mann-Whitney test), higher levels of β/WM in persistent group (P = 0.023, Mann-Whitney test) and also higher levels of C/WM in persistent group (P = 0.004, Student's t test). CONCLUSIONS: Higher ratios involving beta-lactoglobulin or casein components were detected in persistent patients. Thus, evaluating these markers precociously can be helpful in predicting CMA evolution.