Role of Fecal Calprotectin in Differentiating Between Hirschsprungs Disease and Functional Constipation

Introduction:Calprotectin is a 36.5 kD calcium and zinc binding protein in the S100 protein family. Fecalcalprotectin levels are elevated in patients with inflammatory bowel disease(IBD) and some other gastrointestinal disorders such as colorectal carcinoma constipation isone of the frequent complaints in children which have different etiologies.The commonest is functional constipation. The others are called organic constipationincluding Hirschsprung s disease which is a frequent congenital disorder (1 in 5000newborns) that results from lack of coordinated propulsive movement of the distal portion ofthe large bowel resulting from the absence of parasympathetic ganglion cells in theintramural and submucosal plexuses. Gold standard for diagnosis is rectal biopsy undergeneral anesthesia, but it is largely replaced by suction or mucosal biopsies nowadays.We decided to evaluate fecal calprotectin level in distinguishing between functional andorganic causes of constipation. To our best knowledge no systematic studies are done in thisregard as yet.Subjects and Methods:Seventy six children aged 1 to 120 months were recruited that all underwent deep rectalmucosal biopsies in our center. Nineteen cases were diagnosed as Hirschsprung’s disease and57 of patients had nerve ganglion cells in their biopsies.Calprotectin concentration was analyzed by ELISA method (Hycult Biotech kit, HK325,Netherlands).Results:In Hirschsprung’s group, median concentration of fecal calprotectin was 20 μg/g (under 0.5to 106) and in functional group median concentration was 4 μg/g (under 0.5 to 110.8).Although the range of fecal calprotectin in two groups were rather wide and differencebetween two groups was not statistically significant, but there was significant differencebetween median of two groups (p: 0.036), however median was not above predeterminedcutoff value of 50 μg/g. Also difference between two groups was statistically significant inmales (under 0.5 to 100 μg/g, mean 3.6 in functional group and under 5 to 106 μg/g, mean27.2 in Hirschsprung’s disease group).Discussion:We propose that fecal calprotectin has limited value in differentiating functionalconstipation from Hirschsprung’s disease with the above cutoff (50 μg/g).