FOXP3 expression, vitamins D and C in the prediction of tolerance acquisition in infants with cow's milk allergy.

BACKGROUND AND OBJECTIVE: Treg cells and dietetic factors may play a significant role in the natural acquisition of tolerance in children with cow's milk allergy (CMA). The best marker for Treg lymphocytes is the transcription factor-forkhead boxP3 (FOXP3). Objective: The paper examines the relationship between Foxp3mRNA expression and serum concentration of vitamins D and C, and the development of different phenotypes of tolerance in children with CMA. MATERIAL AND METHODS: The study group comprised 138 infants with CMA and 101 healthy infants. All children underwent oral food challenge, first with an extensively-heated milk product and then with unheated products. FOXP3mRNA expression and serum vitamin C and D concentration were evaluated. RESULTS: At two years of life, 54 (39.1%) children still displayed CMA, 43 (31.2%) were unheated milk-reactive and heated milk-tolerant, while 41 (29.7%) were classified as outgrown. The mean level of FOXP3 expression in the studied group was 2.07±1.23; this was lower than the control group value of 2.98±1.52 (p<0.001). A value below 1.45 indicated allergy. The mean serum level of vitamin D in the study group (29.67±7.09 ng/ml) was lower than in the control group, 33.35±4.13 ng/ml (p<0.001). No significant differences in mean serum vitamin C content were found. CONCLUSIONS: Increased Foxp3mRNA expression can predict faster acquisition of tolerance in infants with CMA. These children have lower serum vitamin D levels than healthy children. No relationship was found between the natural history of CMA and serum vitamin C concentration.