Findings of granulomatous colitis and partial reduction in neutrophil oxidase activity as measured by DHR123 assay. (A) Diffuse aphthous ulcerations () were visible throughout the colon at the time of presentation. Biopsies showed prominent epithelioid granulomata in lymphoid aggregates (B, ) and in lamina propria (C) with giant cells (inset). Four-μm sections were stained using hematoxylin and eosin prior to microscopy and photomicrographs were taken with a Nikon Eclipse 80i microscope equipped with a Nikon Digital Sight DS-U1 camera using 20×/0.50NA and 40×/0.75NA objectives. (D) DHR123 fluorescence in control (black line) and patient (red line) neutrophils before and after stimulation with 0.6 μg/mL PMA (representative of 5 assays).