title: Antigen-specific free immunoglobulin light-chain antibodies: could it be a new diagnostic marker for patients with allergy?
abstract: OBJECTIVE
  Human free immunoglobulin light chains (FLCs) have long been considered as nonmeaningful spillover remnants from the process of immunoglobulin production; however, recent findings suggest that the antibody activity of FLCs may be involved in the pathology of allergic responses. We therefore assessed the antigen-binding ability of FLCs to evaluate their usefulness as diagnostic markers for patients with allergy.
  
  
  METHODS
  FLCs were separated from the serum samples of patients seropositive against cedar pollen and mice immunized with bovine serum albumin and 1-fluoro-2,4-dinitrobenzene by ultrafiltration and protein G absorption. A sensitive immunoassay confirmed the absence of any IgG in the separated FLC fractions from the human serum samples.
  
  
  RESULTS
  Solid-phase immunoassay for cedar pollen showed that none of the human serum samples possessed any antibody activity against the antigen after the removal of whole immunoglobulins. Furthermore, while the immunized mice also showed high antibody titers against the antigens, but the serum specimens showed no residual antibody activity against the antigens after the FLCs were separated from the whole immunoglobulins.
  
  
  CONCLUSIONS
  The results of the present study suggested that the FLC fractions may possess little or no antigen-binding activity, and that therefore, they may not serve as useful diagnostic markers in patients with allergy.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Iruma-gun, Saitama 350-0495, Japan. tnakano@saitama-med.ac.jp <tnakano@saitama-med.ac.jp>
authors.forename: Takanari
authors.initials: T
authors.lastname: Nakano
authors.forename: Hidenori
authors.initials: H
authors.lastname: Takahashi
authors.forename: Shuichi
authors.initials: S
authors.lastname: Miyazaki
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Kawai
authors.forename: Rina
authors.initials: R
authors.lastname: Shinozaki
authors.forename: Tsugikazu
authors.initials: T
authors.lastname: Komoda
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nagata
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000378:metabolism; D000906:Antibodies; D000937:Antigen-Antibody Reactions; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000097:blood*; D007147:Immunoglobulin Light Chains / Q000032:analysis* / Q000097:blood*; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D018926:Anti-Allergic Agents; D000906:Antibodies; D007147:Immunoglobulin Light Chains