TY - JOUR T1 - Circulating human IgG autoanti-IgE antibodies in asthma patients block the binding of IgE to its high affinity receptor JF - Clinical Molecular Pathology JO - Clin Mol Pathol SP - M148 LP - M152 DO - 10.1136/mp.48.3.M148 VL - 48 IS - 3 AU - S J Smith AU - A Galvin AU - I Hall AU - F Shakib Y1 - 1995/06/01 UR - http://mp.bmj.com/content/48/3/M148.abstract N2 - Aims—To investigate the ability of circulating human IgG autoanti-IgE antibodies from asthma patients to block the binding of IgE to the α chain of the high affinity receptor (FcεRI).Methods—This involved the use of a well validated flow cytometric method to detect inhibition of FITC labelled IgE binding to a fibroblast cell line (CHK1E1) transfected with the α chain of FcεRI.Results—IgG autoanti-IgE-containing sera blocked the binding of IgE-FITC to the CHK1E1 cells. No such inhibition was demonstrable with rheumatoid sera containing autoanti-IgG (that is, rheumatoid factor) but lacking autoanti-IgE. Percentage inhibition (up to 50%) of IgE binding to the CHK1E1 cells was directly related to the titre of IgG1, but not IgG4, autoanti-IgE in the sera tested (correlation coefficient 0·66, probability 0·003).Conclusions—The capacity of anti-IgE to block the binding of IgE to FcεRI has important clinical implications, particularly in terms of downregulation of allergic reactions. ER -