Sinnhaftigkeit von IgG-Bestimmungen bei chronischen gastrointestinalen Beschwerden?

Abstract

A 23-year-old patient has suffered from meteorism and occasional diarrhea for 8 years. Specific IgG antibodies directed towards multiple foods had been determined elsewhere. A concordant elimination diet had led to loss of body weight of 10 kg (remaining body weight 40 kg) without any improvement of the symptoms. At the time of first presentation in our Allergy Unit, a concise allergological work-up had not been performed. The skin prick testing of inhalant allergens, foods, spices, flour, preservatives and latex-associated foods showed 3+-positive reactions to grass pollen, rye pollen, dermatophagoides pteronyssinus, pepper, wheat flour and rye flour; 2+-positive reactions to curry, sodium proprionate and sorbic acid. Determination of specific IgE antibodies to rye flour, wheat flour, pepper and curry were negative, as well as serology for celiac disease. After dramatic weight loss due to elimination diet of 87 foods according to IgG antibodies identified elsewhere, positive prick test results were found to the above mentioned foods and food additives (pepper, wheat- and rye flour, curry as well as sodium proprionate and sorbic acid). A clinically relevant IgE-mediated allergy could be ruled out by an elimination diet to these positive tested foods that did not lead to any improvement of the clinical symptoms. A double-blind placebo-controlled food challenge (DBPCFC) to wheat and rye flour was refused by the patient. A Pillcam endoscopy revealed an inflammatory alteration of the mucous membran of the terminal ileum. Due to a suspected early stage of Crohn's disease, a coloscopy and a double-ballon endoscopy is scheduled. As in the presented case, determination of IgG antibodies raised against foods is not a feasible measure for diagnosis of gastrointestinal disorders and may lead to a significant delay in correct diagnosis and therapy of the underlying disease.