Rapid recovery of TREC content.

(A) TREC content of purified CD4⁺ T cells was not significantly different from control values as early as 6 months after PSCT. (B) TREC content correlated significantly with the proportion of dividing CD4⁺ T cells (C) but not with the number of naive CD4⁺ T cells. (D) TREC content did depend on the presence of clinically documented GVHD or infectious complications. Hence, patients with inflammatory complications (group 2) had significantly lower CD4⁺ TREC content than patients without such complications (group 1). Horizontal bars indicate median values. White circles, group 1 patients; cross-hair circles, group 2 patients; gray circles, control values. Depicted are data obtained 3 months after PSCT. Similar data were obtained for the other time points and for CD8⁺ T cells (data not shown).