TRECs levels correlate significantly with CD4 naïve T cell
numbers
To examine the correlation between T cell subsets and TRECs levels, we
analyzed the absolute numbers of different T cell subsets in the 410
healthy children. There was a correlation between TRECs levels and the
numbers of CD3 T cells (r 0.220, p<0.0001) (Fig. 4A) and CD4 T
cells (r 0.318, p<0.0001) (Fig. 4B). We also found a
significant correlation between TRECs levels and CD4+CD45RA+CD27+ (CD4
naïve) T cell numbers (r 0.305, p<0.0001) (Fig. 4C). However,
there was no correlation between TRECs levels and CD8+/CD8+CD45RA+CD27+
(CD8 naïve) T cell numbers (p>0.1) (Fig. 4D/E), or between
TRECs levels and CD4+/CD8+ central memory T cell or CD4/CD8 effector
memory T cell numbers (Fig. 4F–H).
Because CD4 naïve T cell numbers showed a strong correlation with TRECs
levels, we next analyzed the correlation between TRECs levels and CD4
naïve T cell numbers in different age groups (Fig. 5). We found
significant correlations between TRECs numbers and CD4 naïve T cell
numbers in the 1–4 y (r 0.243, p 0.023) (Fig. 5D) and 4–8 y (r 0.409,
p<0.0001) age groups (Fig. 5E).