Increased levels of hyaluronan and albumin after intestinal challenge in adult patients with cow's milk intolerance

Background The mechanisms for adverse reactions to foods in the gastrointestinal tract are poorly understood. Presently, only limited possibilities are available for identification of adverse immunological reactions to different foods. Objective The intestinal inflammatory reactions in adult patients with a history of milk-related gastrointestinal symptoms were studied after intestinal challenges by a jejunal perfusion technique and compared with the reactions in a control group. Methods Five skin-prick test and radioallergosorbent test negative and lactose tolerant patients with a history of milk-related gastrointestinal symptoms, verified by double-blind placebo-controlled challenge, and eight healthy controls were investigated. Perfusions were performed allowing analyses of a well-defined 'closed' jejunal segment. Milk perfusions were performed in patients and controls after an overnight fast. Ten millilitres of milk were administered to the segment at 3 mL/min. The jejunal fluid levels of hyaluronan (hyaluronic acid) and albumin were measured. Results In the five patients the milk challenges induced as a mean fivefold increased levels of hyaluronan compared with prestimulation values, whereas no such increases were seen in the control subjects. Albumin, as a marker of plasma leakage, was also increased in the patients but not in the control subjects. Conclusion The underlying mechanisms for locally increased levels of hyaluronan and also albumin in the intestinal lumen may be secretion of lymph rich in hyaluronan and reflect the mucosal oedema. This capacity of the intestinal mucosa to react with lymph leakage towards a locally infused allergen may be a possible way to delineate gastrointestinal reactions in food-related disorders.