title: [Clinical usefulness of serum free light chain measurement in monoclonal gammopathy].
abstract: Recently, a highly sensitive assay (FREELITE) capable of measuring serum immunoglobulin-free light chains (FLC) was developed. An abnormal kappa/lambda ratio supports the presence of clonal plasma cell expansion. Using this assay, we measured serum and urine samples of 178 healthy volunteers, 184 patients with polyclonal gamma-globulinemia and 150 patients with monoclonal gamma-globulinemia. The diagnostic sensitivity of the FLC assays for monoclonal gammopathies was 88.0% and the specificity for healthy volunteers and polyclonal gammopathies was 96.1%. The minimal detection sensitivity of this assay for serum FLC was 0.3 mg/l and was greater than 100-fold more sensitive than serum protein electrophoresis (SPE). The combination of FLC with SPE and immunoelectrophoresis identified 99% of patients with monoclonal gammopathies. Effective treatment often leads to a more rapid reduction of the involved FLC level relative to the intact immunoglobulin or total light chain concentration because the half-life of FLC is <6 hours. These observations suggest that FREELITE is useful for diagnosis, disease monitoring and assessment of response to treatment in patients with monoclonal gammopathies such as multiple myeloma and AL amyloidosis.
authors.affiliation: Division of Hematology and Oncology, Kyoto Prefectural University of Medicine.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Shimazaki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Murakami
authors.forename: Morio
authors.initials: M
authors.lastname: Sawamura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Matsuda
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hata
authors.forename: Isamu
authors.initials: I
authors.lastname: Sugiura
authors.forename: Keitaroh
authors.initials: K
authors.lastname: Tsushita
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nagura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kosugi
authors.forename: Junji
authors.initials: J
authors.lastname: Itoh
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000652:urine; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007122:Immunoelectrophoresis; D007147:Immunoglobulin Light Chains / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000175:diagnosis*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007147:Immunoglobulin Light Chains; D011933:Reagent Kits, Diagnostic