Milk protein IgG and IgA: The association with milk-induced gastrointestinal symptoms in adults

Abstract

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.

IgG and IgG4 antibodies in subjects with irritable bowel syndrome: a case control study in the general population

“…Food-specific IgG values may reflect exposure to a specific food [5]. In support of our results, decreased IgE levels were associated with elevated levels of IgG antibodies against milk in individuals who had developed a tolerance to cow’s milk after experiencing an allergy to the same product [17], and subjects drinking milk had higher levels of milk IgG in their sera than did non-milk drinkers in one study [18]. …”

Characteristics of patients suffering from cow milk allergy

“…Hochwallner et al found that cow milk protein intolerance patients couldn't be distinguished from persons without cow milk protein intolerance on the basis of IgG subclass or IgA antibody levels to purified recombinant alpha S1-casein, alpha S2-casein, beta-casein, kappa-casein, alpha-lactalbumin, and beta-lactoglobulin [23]. Anthoni et al found that milk protein IgG but not milk IgA seemed to be associated with self-reported milk-induced gastrointestinal symptoms [22]. In our study, serum cow milk-specific IgG was elevated in 65 CMA patients, while the total IgG levels were increased in 20 patients.…”

“…In the present study we employed electrochemiluminescence immunoassay method, which was more sensitive than the fluorescence-labeled antibody assays [21]. The diagnostic value of specific IgG antibodies against cow milk proteins (CMP) is controversial because the production of these antibodies is a normal physiologic response following exposure to CMP [22]. Hochwallner et al found that cow milk protein intolerance patients couldn't be distinguished from persons without cow milk protein intolerance on the basis of IgG subclass or IgA antibody levels to purified recombinant alpha S1-casein, alpha S2-casein, beta-casein, kappa-casein, alpha-lactalbumin, and beta-lactoglobulin [23].…”

Is perceived intolerance to milk and wheat associated with the corresponding IgG and IgA food antibodies? A cross sectional study in subjects with morbid obesity and gastrointestinal symptoms

“…The novelty of the present study is that IgG and IgA antibodies directed against milk and wheat were compared between subjects who all reported GI complaints, but who did or did not perceive themselves as intolerant to these foods. Dietary intake of the offending foods was also estimated, as dietary restrictions have been suggested to affect serum concentrations of the antibodies in some studies [ 22 – 24 ]. Milk/dairy consumption was lower and close to the level of statistical significance in those with than without perceived milk intolerance.…”