Expression of alpha 4 beta 7 integrin on memory CD8 super(+) T cells at the presentation of acute intestinal GVHD

Acute intestinal GVHD remains a major source of morbidity after allogeneic hematopoietic cell transplantation (HCT). alpha 4 beta 7 integrin is a cell surface molecule that mediates lymphocyte trafficking to intestinal tissue. In this analysis, peripheral blood was collected at the time of presentation of symptoms of acute GVHD and before any treatment. In all, 45 samples were collected and divided into three groups on the basis of subsequent evaluation: intestinal GVHD (n=15), skin GVHD (n=20) and no GVHD (n=10). Two patients developed intestinal GVHD after DLI. The no-GVHD group comprised 10 patients who presented with suspicious symptoms, but evaluation yielded other etiologies. Analysis by flow cytometry showed that intestinal GVHD patients had a significantly higher percentage of alpha 4 beta 7 integrin-expressing memory CD8 super(+) T cells (median 7.69%; lower and upper quartiles, 1.06% and 11.64%, respectively) compared with patients with skin GVHD (1.26%; 0.57% and 2.49%) and no GVHD (0.96%; 0.44% and 1.85%), P=0.03. No differences were found in alpha 4 beta 7 expression in any CD4 super(+) T-cell subsets or naive CD8 super(+) T cells. This study adds to the evidence that alpha 4 beta 7 integrin is involved in lymphocyte trafficking in acute intestinal GVHD.