title: Heparin inhibits the immediate response to antigen in the skin and lungs of allergic subjects.
abstract: Although heparin is used as an anticoagulant, its biologic function remains unclear. Substantial evidence exists that suggests it may modulate many aspects of immune function and inflammation. We demonstrated, in a double-blind, placebo-controlled, crossover study involving 10 allergic subjects, that a small dose of heparin (25 U/kg) administered intravenously 10 min before challenge reduced the acute cutaneous reaction to 10 allergens and histamine from a group-average sum of mean (+/- SD) wheal diameters at a baseline of 29.9 +/- 10 mm and after normal saline placebo (29.5 +/- 10.7 mm) to after heparin (14.4 +/- 10.4 mm) (p < 0.02, Wilcoxon's signed rank test). In 15 subjects with asthma and dust mite allergy, nebulized heparin 20,000 units administered in a double-blind, placebo-controlled, crossover fashion 10 min before challenge inhibited the bronchospasm induced by inhaled dust mite extract. Log2 of the provocative dose of mite extract causing a 20% fall in FEV1 at baseline was 4.1 +/- 1.5 protein nitrogen units (PNU); after normal saline it was 4.5 +/- 2.0 PNU, and after heparin it was 5.1 +/- 2.5 PNU (p = 0.04). These data suggest heparin may have an inhibitory role in acute mast-cell-mediated allergic inflammation.
authors.affiliation: Department of Respiratory and Intensive Care Medicine, Mater Adult Hospital, South Brisbane, Queensland, Australia.
authors.forename: S D
authors.initials: SD
authors.lastname: Bowler
authors.forename: S M
authors.initials: SM
authors.lastname: Smith
authors.forename: P S
authors.initials: PS
authors.lastname: Lavercombe
mesh_terms: D000328:Adult; D000336:Aerosols; D000485:Allergens / Q000276:immunology*; D000818:Animals; D000941:Antigens / Q000276:immunology; D004311:Double-Blind Method; D005541:Forced Expiratory Volume; D006493:Heparin / Q000494:pharmacology*; D006632:Histamine / Q000008:administration & dosage; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D008925:Mites; D012130:Respiratory Hypersensitivity / Q000276:immunology* / Q000503:physiopathology; D012882:Skin Tests
chemical_list: D000336:Aerosols; D000485:Allergens; D000941:Antigens; D006632:Histamine; D006493:Heparin