Neuroimmune interaction and anorectal motility in children with food allergy-related chronic constipation.
OBJECTIVE
Food allergy is thought to trigger functional constipation in children but the underlying mechanisms are still unknown. Mast cells (MCs) and their relationship with nerve fibers (NFs) in the rectal mucosa, as well as anorectal motility, were studied in children with refractory chronic constipation before and after an elimination diet for cow's milk, egg, and soy proteins.


METHODS
Thirty-three children (range: 1-10.8 years) underwent anorectal manometry and suction rectal biopsy before and after 8 weeks of oligoantigenic diet. MCs and NFs were identified immunohistochemically. Quantification of MCs (%MC/area) and MCs within 10 microm of NFs (%MC-NF/area) was performed by computer-assisted analysis.


RESULTS
Eighteen children responded to the diet (R-group) and fifteen did not (the NR-group). At baseline there was a significant difference in anal resting pressure (ARP; mm Hg), percentage of relaxation (%R), and residual pressure (RP; mm Hg) of anal canal during rectal distension between the R-group (66+/-4.1, 84.3+/-2.8, 10.4+/-2.3, respectively) and the NR-group (49+/-5, 92.2+/-1.7, 4.8+/-1.7, respectively; P<0.05). After the diet, significant changes in ARP, RP, and %R were observed only in the R-group (44+/-3.7, 93.7+/-1.5, 3.8+/-1.2, respectively; P<0.05). At baseline, the R-group showed an increase in %MC/area (8.3+/-0.7) and %MC-NF/area (5.2+/-2.6) with respect to the NR-group (5.1+/-0.5 and 2.3+/-0.4, respectively; P<0.05). After the diet, only the R-group showed a significant reduction of %MC/area and %MC-NF/area (4.4+/-0.5 and 2.2+/-0.4, respectively; P<0.001). Both ARP and RP significantly correlated with %MC/area and %MC-NF/area; %R showed a significant inverse correlation with both %MC/area and %MC-NF/area.


CONCLUSIONS
In children with food allergy-related chronic constipation, an increase in both rectal MC density and spatial interactions between MCs and NFs correlates with anal motor abnormalities. These variables are significantly affected by the diet.
Borrelli
Osvaldo
O
Division of Pediatric Gastroenterology and Hepatology, Department of Pediatrics, University "La Sapienza," Rome, Italy.
Barbara
Giovanni
G
Di Nardo
Giovanni
G
Cremon
Cesare
C
Lucarelli
Sandra
S
Frediani
Tullio
T
Paganelli
Massimiliano
M
De Giorgio
Roberto
R
Stanghellini
Vincenzo
V
Cucchiara
Salvatore
S
D001003:Anal Canal / Q000294:innervation / Q000473:pathology / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D003248:Constipation / Q000178:diet therapy / Q000209:etiology / Q000503:physiopathology*; D003672:Defecation / Q000502:physiology; D005260:Female; D005512:Food Hypersensitivity / Q000150:complications / Q000178:diet therapy / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D008297:Male; D008365:Manometry; D008407:Mast Cells / Q000502:physiology; D009043:Motor Activity / Q000502:physiology*; D009412:Nerve Fibers / Q000502:physiology; D015213:Neuroimmunomodulation / Q000502:physiology*; D012007:Rectum / Q000294:innervation / Q000473:pathology / Q000503:physiopathology*