Colonoscopic allergen provocation (COLAP): a new diagnostic approach for gastrointestinal food allergy.

Background: The clinical relevance of gastrointestinal food allergy in adults is largely unknown because the mechanisms are poorly understood and the diagnosis is difficult to confirm.

Aims: To improve the diagnostic means for confirming intestinal food allergy on an objective basis, a new colonoscopic allergen provocation (COLAP) test was developed.

Patients: The COLAP test was performed in 70 adult patients with abdominal symptoms suspected to be related to food allergy, and in five healthy volunteers.

Clinical significance of the colonoscopic allergen provocation test.

Background: To improve the diagnosis of intestinal allergy, we developed a colonoscopic allergen provocation (COLAP) test.

Methods: The cecal mucosa was challenged with three food antigen extracts, a buffer control and a positive control (histamine). The mucosal wheal and flare reaction was registered semiquantitatively 20 min after challenge, and selected tissue biopsies were examined for mast cell and eosinophil activation by immunohistochemistry and electron microscopy.

Mechanisms of human eosinophil activation by complement protein C5a and platelet-activating factor: similar functional responses are accompanied by different morphologic alterations.

The complement system is an important amplification system for the propagation of allergic as well as pseudoallergic inflammatory reactions. In the present study, the effect of the major anaphylatoxin C5a was compared with that of platelet-activating factor (PAF) on highly purified eosinophils (> or = 95%) by functional as well as morphologic criteria. Upon stimulation with C5a, eosinophils maintained their spheric structure, developing short, pseudopodia-like protrusions, whereas PAF induced the generation of a number of digitating protrusions.

TNF alpha-induced activation of eosinophil oxidative metabolism and morphology--comparison with IL-5.

Human dermal mast cells are capable of releasing cytokines, particularly preformed TNF alpha, upon appropriate stimulation. Mast cell activation in vivo was shown to be associated with an influx and activation of inflammatory cells, initially PMN (polymorphonuclear neutrophilic granulocytes) then eosinophils. In order to learn more about the mechanisms by which TNF alpha is capable of activating eosinophils, in the present study the effect of TNF alpha on morphology and function of highly purified normal eosinophils (> or = 95%) was examined.