Role of IgG anti-β-lactoglobulin antibody in the diagnosis of cow’s milk protein intolerance in India

Abstract

Objective: Little is known about cow’s milk protein intolerance (CMPI) in India. This study was aimed at finding CMPI cases and determining the role of IgG anti-β-lactoglobulin antibody in the diagnosis of this condition in India. Methods: From June 2004 to December 2005, 30 children with presumptive diagnosis of CMPI, based on endoscopic rectal or duodenal biopsy showing excess eosinophils and response to milk withdrawal, were enrolled and studied prospectively. Definite diagnosis was made in 20 children on the basis of positive milk challenge. IgG anti-β-lactoglobulin antibodies were tested in children with CMPI before and after stopping milk and after milk challenge. Antibody levels were also studied in 27 age-matched disease controls and 50 healthy adults. Results: The median age of 20 children (16 boys) with CMPI was 16.5 (6–36) months. Of them, 18 presented with diarrhea (12 bloody) and 2 had rectal bleeding. The presumptive diagnosis was most often (85%) based on colonic or rectal biopsy findings. Rectal biopsy was diagnostic in all 20 cases irrespective of the mode of presentation compared with duodenal biopsy which was diagnostic in 3 cases (p<0.0001). There was no difference in antibody levels between cases and controls; the antibody level decreased significantly after milk withdrawal (p<0.005), but did not rise significantly after milk rechallenge. Conclusions: CMPI is a common cause of chronic diarrhea in children in northern India. Sigmoidoscopy and rectal biopsy help in establishing the diagnosis in most cases. IgG anti-lactoglobulin antibody test is not useful in diagnosing CMPI in the Indian setting.