FECAL CALPROTECTIN AND COW'S MILK PROTEIN ALLERGY IN INFANTS

Abstract

Calprotectin, a 36.5 kiloDalton protein released into the intestinal lumen by macrophages and neutrophils, has been shown to be useful in determining disease activity and treatment response in intestinal inflammatory conditions such as inflammatory bowel disease. Cow's milk protein allergy (CMPA) is a common gastrointestinal problem of infancy associated with rectal bleeding, emesis, diarrhea, and eczema. We hypothesized that fecal calprotectin is a useful screening test to evaluate for resolution of CMPA in infants. A pilot trial was performed in six infants less than 90 days of age with rectal bleeding and other symptoms consistent with cow's milk protein allergy. Fecal calprotectin levels were determined by ELISA assay at baseline, 3, and 6 weeks after placement on a protein hydrolysate formula. All infants improved clinically and rectal bleeding resolved within 6 weeks after conversion to a hydrolysate formula. Initial fecal calprotectin levels ranged from 135-1537 mg/L (mean 557 mg/L) and decreased to a range of 42-219 mg/L (mean 163 mg/L) after 6 weeks on protein hydrolysate formula. A control patient with no symptoms of CMPA maintained fecal calprotectin values between 97 and 129 mg/L throughout the study. The results of this pilot trial suggests that fecal calprotectin may be a useful screening test for treatment response to protein hydrolysate formula; however, further studies with a larger number of patients are necessary to determine the utility of this test in infants with CMPA.