Fig. 1

Small intestinal histopathology in MNGIE patients. a, b Hematoxylin-Eosin (H&E) stains of the small intestine of control subjects (a) and MNGIE patients (b) show normally layered organization of the wall in both groups (M: tunica mucosa; SM: tunica submucosa; MP: tunica muscularis propria; S: tunica serosa). c, d Compared to controls (c), phosphotungstic acid-hematoxylin (PTAH) stains of MNGIE small intestines (d) show thinning of the external layer of the tunica muscularis propria (blue, arrows). e Quantification demonstrates muscle wall atrophy in the three MNGIE patients compared to two controls. One control was omitted because the tunica muscularis was incompletely present. f, g Immunostain against calretinin shows presence of ganglion cells in the submucosal Meissner plexus of controls (f) and MNGIE patients (g). h Quantification of myenteric ganglion cells shows similar cell density in MNGIE patients and controls when identifying cells with calretinin (p = 0.99) and NeuN (p = 0.63, not shown). i, j Immunostain against CD117 shows normal presence of interstitial Cajal cells around grouped myenteric ganglion cells in controls (i), whereas Cajal cells are completely depleted in MNGIE patients (j). Small immunopositive cells in J are mast cells. (k, l) Immunostain against the glial fibrillary acidic protein (GFAP) shows normal immunoreactivity in myenteric ganglion and enteric glia cells in MNGIE (l) as in controls (k). In both graphs bars denote the median. Original magnifications (a, b): 12.5x; (c, d): 25x; (i, j): 400x; (k, l): 200x. ***P < 0.001