[1763] Pediatric Patients with Non-Specific Abdominal Pain: A Mast Cells-Associated Disorder?

S Sharma, E Davis, T Gibbons, AG Saad. University of Arkansas for Medical Sciences, Little Rock, AR

Background: Studies have shown that mast cells and other immunocytes are increased in the colonic mucosa of adult patients with irritable bowel syndrome (IBS). Several lines of evidence support the hypothesis that a low-grade mucosal inflammatory process, albeit undetectable endoscopically or with conventional histology, may play a role in IBS pathogenesis. We recently noticed increased number of mast cells in the colonic mucosa of pediatric patients who presented with non-specific abdominal pain. The role of colonic mucosal mast cells in children with non-specific abdominal pain has not been previously explored.
Design: Pediatric patients presented with non-specific abdominal pain, normal colonoscopy findings and apparently normal colon biopsies histology. The control group consisted of 12 autopsy cases of patients who died because of isolated central nervous system diseases. Colonic biopsies from patient and control groups were stained with CD117. In each region of the colon, the area with the highest number of mast cells (hot spot) was selected and the number of mast cells was counted per one high power field (X400).
Results: The patients group consisted of 36 patients (median age 11.22 years). The control group consisted of 12 autopsies (median age 10.3 years). Clinical presentations of the patients group included abdominal pain, abnormal bowel movement, blood in stools and joint pain with the most common diagnosis being recurrent abdominal pain (70%) and the most common symptom (after pain) being chronic diarrhea. Histologic examination of both groups showed no pathologies beside increased number of mast cells in the patients group. Details of the numbers of mast cells in various parts of the colon in the patients and controls groups along with the corresponding P value are in Table 1.

Table 1

Anatomic location	Patients Group		Controls Group		P-value
	Median	Range	Median	Range
Cecum	22	10-39	5	2.3-8.4	<0.0001
Ascending colon	23	8-42	5.6	4.4-7.9	<0.001
Transverse colon	22	4-35	4.5	2.2-9.1	<0.001
Descending colon	20	6-37	6.1	3.8-9.3	<0.0003
Recto-sigmoid	22	6-40	8.3	4.1-9.8	<0.004

Conclusions: There was pancolonic increased number of mast cells in the patients group compared to the controls group. These findings are similar to those reported in the adult population with IBS. It is tempting to hypothesize that these patients may benefit from anti-histamines or other mast cells stabilizers.
Category: Pediatrics

Monday, March 22, 2010 1:00 PM

Poster Session II # 199, Monday Afternoon