[744] Interstitial Cells of Cajal (ICC) and Nerve Fiber Changes in the Gastric Muscle of Patients with Diabetic Gastroparesis

C Subramony, J Hughes, J Hughes, C Lahr, D Spree, SA Bigler, T Abell. University of Mississippi Medical Center, Jackson, MS

Background: Normal gastric motility depends upon the integrity of the smooth muscle cells richly supplied by a network of neuronal cell processes from the nerve plexuses and the interstitial cells of Cajal (ICC) which in smooth muscle relay electric impulses from the inter-muscular plexus to the smooth muscle cells, thereby modulating gut motility. Animal studies have shown reduced numbers of ICC in gastroparesis. Here, the number of ICC and neuronal cell processes observed in gastric biopsies from patients with diabetes (DM) and gastroparesis (GP) was compared with those seen in gastric tissues obtained post-mortem.
Design: Full-thickness gastric biopsies were obtained from thirty patients (23 w,7 m; mean age of 49.8 yrs) with drug-refractory DM GP during surgery to implant a permanent gastric electrical stimulator and gastric tissues were obtained from 19 control patients post-mortem (6 w,13 m, mean age of 43.6 yrs; includes 1 w and 1m with DM). Immunostains with antibodies directed against CD117 (for ICC) and S-100 protein (for neuronal processes) were performed on paraffin-embedded sections. CD117 positive cells and S-100 protein positive fibers in the outer longitudinal (outer) and the inner circular (inner) muscular layers of the muscular is propria were counted in ten high power fields (x400 magnification). The mean number of cells or fibers per high power field was calculated for each patient and control.
Results: Our findings differed from those reported for animal studies (Table 1). The number of CD117 cells did not differ between groups. However, significantly fewer S-100 positive nerve fibers were seen in samples from DM GP patients.

	Diabetics	Controls	p value
S-100 outer muscle	6.3	20.7	0.00001
S-100 inner muscle	13.4	26.1	0.009
CD117 outer muscle	5.36	6.97	0.42
CD117 inner muscle	9.9	6.67	0.025
Ratio CD117/S100 outer muscle	1.49	0.427	0.008
Ratio CD117/S100 inner muscle	1.07	0.364	0.003

Conclusions: Patients with diabetic gastroparesis had significantly fewer nerve fibers in both the inner and outer muscle layers than non-gastroparetic controls. ICC were seen in greater numbers in the inner muscle layer of diabetic patients with gastroparesis than were seen in control patients. Further studies correlating histologic changes with direct gut electrophysiology may reveal clinically useful information.
Category: Gastrointestinal

Monday, March 22, 2010 1:00 PM

Poster Session II # 78, Monday Afternoon