title: Hyperosmolarity selectively enhances IgE-receptor-mediated histamine release from human basophils.
abstract: Increased osmotic pressure has been reported to cause non-cytotoxic histamine release (HR) from human basophils, as well as a potentiation of HR induced by anti-IgE. In this study, the effects of hyperosmolar Na-K-acetate (300-600 mOsm/kg H2O) on HR was studied in washed human blood cells from newborns, adult volunteers and patients with severe atopic dermatitis. These three patient groups represented 3 very distinct populations with respect to total plasma IgE content, medians were less than 0.2 IU/ml, 20.5 IU/ml and 2508 IU/ml; respectively. Increasing osmolarity to 500 mOsm/kg H2O caused little HR in the absence of other stimuli, whereas at 600 mOsm/kg H2O a significant increase in spontaneous HR was seen. The HR induced by anti-IgE and Concanavalin A, acting through the IgE-receptor, was increased approximately twofold at 500 mOsm/kg H2O. Responses were highly correlated to results at 300 mOsm/kg H2O. The use of 600 mOsm/kg H2O buffers caused a further increase in most, but not all blood samples. The potentiation of IgE-receptor-mediated HR when using hyperosmolar media was clearly independent of plasma IgE contents, and did not change the concentration-response to anti-IgE. In contrast, HR induced by the IgE-receptor-independent stimuli, Formyl-met-leu-phe and calcium ionophore A 23187, were not enhanced at all by increased osmotic pressure. We conclude, that hyperosomolar media selectively enhance IgE-receptor-mediated HR. The use of hyperosmolar media may therefore be beneficial in a diagnostic application of washed blood HR assays used in allergy diagnosis.
authors.affiliation: Department of Pediatrics, University Hospital of Aarhus, Denmark.
authors.forename: B W
authors.initials: BW
authors.lastname: Nielsen
authors.forename: T
authors.initials: T
authors.lastname: Bjerke
authors.forename: T M
authors.initials: TM
authors.lastname: Damsgaard
authors.forename: T
authors.initials: T
authors.lastname: Herlin
authors.forename: K
authors.initials: K
authors.lastname: Thestrup-Pedersen
authors.forename: P O
authors.initials: PO
authors.lastname: Schiøtz
mesh_terms: D000085:Acetates; D000476:Alkanesulfonates; D017738:Alkanesulfonic Acids; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology*; D001491:Basophils / Q000378:metabolism*; D002021:Buffers; D003876:Dermatitis, Atopic / Q000097:blood*; D005312:Fetal Blood / Q000166:cytology / Q000378:metabolism*; D006636:Histamine Release / Q000502:physiology*; D006801:Humans; D007073:Immunoglobulin E; D009994:Osmolar Concentration; D010879:Piperazines; D011961:Receptors, Fc / Q000502:physiology*; D017455:Receptors, IgE; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D000085:Acetates; D000476:Alkanesulfonates; D017738:Alkanesulfonic Acids; D000944:Antigens, Differentiation, B-Lymphocyte; D002021:Buffers; D010879:Piperazines; D011961:Receptors, Fc; D017455:Receptors, IgE; D007073:Immunoglobulin E; C008916:piperazine-N,N'-bis(2-ethanesulfonic acid)