“…The distribution pattern of B cells in the lamina propria of intestinal mucosa beyond the lymphoid follicles has not been reported for human infants. We hypothesize that this distribution may be patchy, in contrast to a more diffuse mucosal distribution pattern for T cells, on the basis of our observations from staining of CD20 + B cells and CD3 + T cells in intestinal mucosa during quiescence after ITx (30), and from our observations of fluctuating recipient B cell contributions to intestinal allograft biopsies taken from different sites at adjacent timepoints (Supplementary Figure 1A). In contrast, recipient T cell representation in these biopsies tends to be more stable at adjacent timepoints (23,25,39).…”