3.1 Correlations between casein components-specific immunoglobulins
Correlations between immunoglobulin levels of each CN component are shown in Figure 1. The αs1-CN-specific IgE levels exhibited a strong positive correlation with the β-CN-specific IgE (r = 0.945, P < 0.001, Figure 1A). κ-CN-specific IgE levels showed relatively lower correlations between αs1-CN-specific IgE levels (r = 0.57, P < 0.001; Figure 1B) and β-CN-specific IgE levels (r = 0.616, P< 0.001; Figure 1C). These results suggested that the patients with CM allergy were sensitized to αs1- and β-CN at the same time, and/or a cross-reactive epitope exists between these two CNs.
Moreover, αs1-, β-, and κ-CN-specific IgG4 and IgA levels were also investigated (Figure S1). The specific IgG4 levels showed the same tendency with IgE. However, IgA levels showed that not only β-CN, but also κ-CN had a strong correlation with αs1-CN.