Cross-sectional analysis of TREC levels in relationship to GVHD.

(A) Individual CD4⁺ (●) and CD8⁺ (○) T-cell TREC levels are shown for a cross-section of patients through 25 years of age with no history of GVHD. (B) Patients through 25 years of age with chronic GVHD. (C) Patients through 25 years of age with a history of GVHD. (D) A composite box plot for TREC levels is shown for all 3 groups. The top, bottom, and line through the middle of the box correspond to the 75th, 25th, and 50th percentile (median) respectively. The whiskers on the bottom and top extend from the 10th percentile and top 90th percentile, respectively. (E) Individual CD4⁺ (closed symbols) and CD8⁺ (open symbols) T-cell TREC levels are shown for a cross-section of patients older than 25 years of age with no history of GVHD (squares), with chronic GVHD (triangles), and with a history of GVHD (circles). Normal range of TREC levels for individuals of ages in groups studied are shown lying between the dashed lines.