Histamine and leukotriene C4 release in cutaneous mosquito-bite reactions.

Background: Mosquito bites are known to sensitize persons, and the most common cutaneous reactions are immediate wheals and delayed bite papules. Anti-saliva IgE and IgG4 antibodies are common in mosquito-sensitive subjects, but mediator release in bite reactions is not known.

Methods: We used the microdialysis technique to measure in vivo histamine and leukotriene C4 release after bite challenges in six mosquito-sensitive subjects.

Histamine release in skin monitored with the microdialysis technique does not correlate with the weal size induced by cow allergen.

The purpose of this study was to monitor histamine release in immediate-type hypersensitivity reactions in the skin of 10 atopic patients, sensitive to cow, by using the microdialysis technique. Three healthy subjects, without any atopic features or background, served as the control group. The probe inserted into the forearm dermal skin was perfused with isotonic saline solution.

Affinity purification of the major bovine allergen by a novel monoclonal antibody.

A monoclonal antibody was developed to the 20 kd major allergen of cow by immunizing mice with crude dander extract. The monoclonal antibody did not exhibit cross-reactivity to cat, dog, and horse dander extracts when studied by ELISA inhibition. The antibody was used in affinity chromatography for the purification of the 20 kd allergen from cow dander extract.

Mast cell proteinases and cytokines in skin inflammation.

The role of mast cells in provoking immediate-type hypersensitivity reactions is well established, but their involvement in chronic inflammation and immune reactions is not so clear. Mast cells synthesize and secrete large amounts of active proteinases, including tryptase, chymase, carboxypeptidase and cathepsin G, which can rapidly process numerous biologically active peptides and proteins or their precursors. Furthermore, mast cells are able to produce a variety of cytokines such as interleukin-4 (IL-4), IL-5, IL-6, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) which are known to be intensively involved in modulating and directing inflammatory responses in the skin.