Objectives: Hirschsprung's disease (HSCR) results from a malformation of the enteric nervous system. A congenital absence of intrinsic ganglion cells from the distal rectum and a variable length of the contiguous bowel is the required diagnostic feature of Hirschsprung's disease and total colonic aganglionosis (TCA). We evaluated the utility of a monoclonal antibody directed against glypican 3 (GPC-3), a membrane bound protein involved in regulation of the signaling of Wingless-types (WNTs), Hedgehogs (Hh), Fibroblast Growth Factors (FGFs), and Bone Morphogenetic Proteins (BMPs), in the detection of ganglion cells in formalin-fixed, paraffin-embedded tissue sections.
Methods: The presence/absence of ganglion cells was evaluated retrospectively by immunohistochemical staining for calretinin and GPC-3 in tissue specimens; a total of 15 patients who underwent colectomy (total or sub-total) for histologically proven aganglionosis (14 HSCR, 1 TCA) and 5 rectal suction biopsies (4HSCR-B, 1 TCA-B) were considered. Of the 20 considered cases, a total of 60 tissue specimens (3 for each patient) were selected. A total of 30 additional normal (N) colonic mucosa biopsy samples were also included.
Results: GPC-3 constantly identified ganglion cell bodies in all but 2 normal biopsies (with normal presentation of ganglion cells on hematoxylin and eosin (H&E) stain), and was negative in all 60 aganglionotic biopsies; these results were reflective of calretinin staining pattern.
Conclusions: The present study indicates that monoclonal anti-GPC-3 might prove to be useful immunohistochemical marker in the identification of ganglion cells in paraffin-embedded rectal tissue specimens and suction biopsies. Further studies in larger series will contribute to demonstrate its utility as an ancillary marker in the histological assessment of HSCR aganglionosis.