CD274 and duodenitis: The histological findings between ICI-Duo and ICI-CeD were similar in the upper GI tract, and in fact closely mimic those of typical CeD with villous blunting, active duodenitis, and patchy increased IELs.26 Immunophenotypic characterization showed that ICI-Duo and ICI-CeD have similar quantities of intraepithelial and lamina propria T cells, CD68+ macrophages, and PD-(L)1 populations.