Patients with pRD present with architectural distortion and T cell infiltrates in colonic tissue. (A) Scatter plots showing CD3⁺ cell counts, CD8⁺ cell counts, CD4⁺ cell counts, frequency of CD45RA⁺ CD4⁺ cells, CD19⁺ cell counts, IgA and IgM concentration, and CD16⁺/CD56⁺ cell counts in peripheral blood of patients at the time of analysis. Each pRD patient is identified with an orange dot, and red triangles indicate patients with IBD. The gray area inside each graph shows the range of values for HD individuals. (B) Bar plots (mean with SD) showing serum cytokine levels in HD (n = 32) and patients with pRD (n = 13). Red triangles indicate pRD subjects with IBD. Statistical analysis was performed using a Mann–Whitney test. (C) Immunohistochemical and RNAscope analyses of colon biopsy isolated from one HD and one pRD patient (P1), showing H&E and CD3 staining, as well as expression of CXCL9 and IFNG transcripts. All images are 10× magnification (scale bars: 100 μm), while IFNG is 40× magnification (scale bar: 20 μm). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. y, years.