title: Immunopurification and measurement of IgE in serum samples from bancroftian filariasis patients.
abstract: Patent infection with Wuchereria bancrofti is associated with increased levels of filaria-specific IgG4 and IgE. In vitro quantification of filaria-specific IgE is hampered by its small proportion in serum relative to other isotypes and by potential competition with IgG4 for the same epitopes on parasite antigens. To determine if IgG4 or other isotypes inhibit the detection of parasite-specific IgE, total IgE was affinity purified prior to filaria-specific IgE enzyme-linked immunosorbent assay. Briefly, anti-human IgE mouse monoclonal antibody 6H10 was coupled to Affigel, and 50 microliters of patient serum was incubated on microcolumns for 16 hr. Total IgE was eluted with 25 mM triethylamine (pH 11.2) and levels of total and filaria-specific IgE and total IgG4 were assessed in the filtrates and eluates. Sera from 14 patients with W. bancrofti microfilaremia (Mf+) and 17 amicrofilaremic patients with chronic pathology (CP) were assayed. Filtrates and eluates were devoid of IgE and IgG4, respectively. The average yield of total IgE in the eluates was 70% (SEM = 6.5; range 21-100%) of that measured in the serum. Antifilarial IgE levels in column eluates were significantly higher in serum samples from CP patients than Mf+ patients. Antibody inhibition of IgE was assessed by comparing the levels of anti-filarial IgE detected in eluates and serum. Evidence for antibody-mediated inhibition of IgE detection was obtained with 2/2 samples from Indian tropical pulmonary eosinophilia patients, but only 2/14 and 4/17 Mf+ and CP patients, respectively.
authors.affiliation: Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30341-3724, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Marley
authors.forename: P J
authors.initials: PJ
authors.lastname: Lammie
authors.forename: M L
authors.initials: ML
authors.lastname: Eberhard
mesh_terms: D000328:Adult; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood* / Q000276:immunology / Q000302:isolation & purification; D000911:Antibodies, Monoclonal / Q000276:immunology; D002846:Chromatography, Affinity; D002908:Chronic Disease; D004605:Elephantiasis, Filarial / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood* / Q000276:immunology / Q000302:isolation & purification; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D014958:Wuchereria bancrofti / Q000276:immunology*
chemical_list: D000909:Antibodies, Helminth; D000911:Antibodies, Monoclonal; D007106:Immune Sera; D007074:Immunoglobulin G; D007073:Immunoglobulin E