[Clinical usefulness of serum free light chain measurement in monoclonal gammopathy].
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.
Shimazaki
Chihiro
C
Division of Hematology and Oncology, Kyoto Prefectural University of Medicine.
Murakami
Hirokazu
H
Sawamura
Morio
M
Matsuda
Masayuki
M
Kinoshita
Tomohiro
T
Hata
Hiroyuki
H
Sugiura
Isamu
I
Tsushita
Keitaroh
K
Nagura
Eiichi
E
Kosugi
Hiroshi
H
Itoh
Junji
J
Shimizu
Kazuyuki
K
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
D015415:Biomarkers; D007147:Immunoglobulin Light Chains; D011933:Reagent Kits, Diagnostic