Brief Article
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Oct 21, 2009; 15(39): 4915-4918
Published online Oct 21, 2009. doi: 10.3748/wjg.15.4915
Milk protein IgG and IgA: The association with milk-induced gastrointestinal symptoms in adults
Sari Anthoni, Erkki Savilahti, Hilpi Rautelin, Kaija-Leena Kolho
Sari Anthoni, Erkki Savilahti, Kaija-Leena Kolho, Hospital for Children and Adolescents, University of Helsinki, PO Box 281, FIN-00029 HYKS, Helsinki, Finland
Hilpi Rautelin, Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki and Helsinki University Central Hospital Laboratory, PO Box 281, FIN-00029 HYKS, Helsinki, Finland
Author contributions: Anthoni S, Savilahti E and Kolho KL designed the research; Savilahti E provided the analytical tools for immunoglobulin assay and participated in writing the paper; Rautelin H performed the Helicobacter pylori antibody determinations; Anthoni S and Kolho KL analyzed the data and wrote the paper.
Supported by Helsinki University Research Funds; Helsinki University Central Hospital Grant and The Research Foundation for Allergy, Finland; The Foundation for Promoting Occupational Medicine in Finland, Helsinki, Finland
Correspondence to: Dr. Kaija-Leena Kolho, Hospital for Children and Adolescents, PO Box 281, FIN-00029, Finland.
Telephone: +358-9-47174787 Fax: +358-9-47172599
Received: February 26, 2009
Revised: September 16, 2009
Accepted: September 23, 2009
Published online: October 21, 2009

AIM: To study the association between serum levels of milk protein IgG and IgA antibodies and milk-related gastrointestinal symptoms in adults.

METHODS: Milk protein IgG and IgA antibodies were determined in serum samples of 400 subjects from five outpatient clinics in Southern Finland. Subjects were randomly selected from a total of 1900 adults undergoing laboratory investigations in primary care. All 400 participants had completed a questionnaire on abdominal symptoms and dairy consumption while waiting for the laboratory visit. The questionnaire covered the nature and frequency of gastrointestinal problems, the provoking food items, family history and allergies. Twelve serum samples were disqualified due to insufficient amount of sera. The levels of specific milk protein IgG and IgA were measured by using the ELISA technique. The association of the milk protein-specific antibody level was studied in relation to the milk-related gastrointestinal symptoms and dairy consumption.

RESULTS: Subjects drinking milk (n = 265) had higher levels of milk protein IgG in their sera than non-milk drinkers (n = 123, P < 0.001). Subjects with gastrointestinal problems related to milk drinking (n = 119) consumed less milk but had higher milk protein IgG levels than those with no milk-related gastrointestinal symptoms (n = 198, P = 0.02). Among the symptomatic subjects, those reporting dyspeptic symptoms had lower milk protein IgG levels than non-dyspeptics (P < 0.05). However, dyspepsia was not associated with milk drinking (P = 0.5). The association of high milk protein IgG levels with constipation was close to the level of statistical significance. Diarrhea had no association with milk protein IgG level (P = 0.5). With regard to minor symptoms, flatulence and bloating (P = 0.8), were not associated with milk protein IgG level. Milk protein IgA levels did not show any association with milk drinking or abdominal symptoms. The levels of milk protein IgA and IgG declined as the age of the subjects increased (P < 0.004).

CONCLUSION: Milk protein IgG but not milk IgA seems to be associated with self-reported milk-induced gastrointestinal symptoms.

Keywords: Abdominal symptoms, Cow’s milk, Food hypersensitivity