CD2 and celiac disease: Cluster analysis showed that the group of children with celiac disease is not homogeneous in terms of serum TAC and TOC levels, with about 50% of these patients (CD2 cluster, n = 15/32) with TAC levels considered insufficient for proper antioxidant defense (<1.3 mmol/L) and TOC levels indicating increased oxidative processes (TOC > 0.35 mmol/L) (Figure 1).