Figure 1

Description of a microcirculation staining pattern with a CD34/CORO1A control case (a) and illustrative examples seen in ABMR as compared to a stable graft case with WARS1 (b, e), TYMP (c, f) and GBP1 (d, g), original magnification × 200 (a–d) and × 400 (e–g). (a) The CD34 highlights endothelial cells of glomeruli and peritubular capillaries, i.e. of the microcirculation, in magenta, while CORO1A acts as a pan-leukocyte marker and highlights inflammatory cells in brown, both in the microcirculation and the interstitium. Note the similarity of the expression pattern with a strong and diffuse microcirculation staining, and to a lesser extent in inflammatory cells, obtained with WARS1 (b) and GBP1 (d). TYMP (c) mainly shows a diffuse and strong staining of inflammatory cells, both in the microcirculation and the interstitium, but also a moderate staining of endothelial cells. (e): A mild but diffuse staining of endothelial cells is observed in a stable graft case with WARS1. (f): In a stable case, TYMP is strongly expressed on a few inflammatory cells, wherever they are, without significant endothelial staining. (g): No significant staining of GBP1 in a stable graft case. Abbreviations: ABMR, antibody-mediated rejection; WARS1, tryptophan–tRNA ligase, cytoplasmic; TYMP, thymidine phosphorylase; GBP1, guanylate-binding protein 1.