T-cell clonal dynamics of GI-identified TCR indicator clones in the blood. (A) Fence plot illustrating change in frequency and rank of GI indicator clones in a representative patient with SR GI aGVHD (patient 5026). Each clone is represented in rank order (most frequent on top) on a sample’s axis by a node with size proportional to the clone’s frequency in the sample. The sample axis represents 100% of the clone counts above background, so the width of a node corresponds to the percent frequency of the clone in the sample. Clones are colored based on whether they show an increase (orange) or decrease (blue) in frequency in blood at day 30 post-Dx vs at time of diagnosis. Clones of rare frequency that were detected below background or were undetected are depicted off-axis as <bkgd or ND, respectively. (B) Fence plot of a representative patient with PR GI aGVHD (patient 4998). (C-D) Number of indicator clones detected in blood of patients at (C) time of diagnosis and (D) day 30 post-Dx. Points represent indicator clone number for individual tissue biopsies. The same number of GI indicator clones are discovered among PR vs SR patients at the time of diagnosis (C; Mann-Whitney, P = .2174). More GI-GVHD indicator clones are detected in blood at day 30 post-Dx in SR compared with PR patients (Mann-Whitney, P < .0001).