title: Monoclonal and polyclonal serum free light chains and clinical outcome in chronic lymphocytic leukemia.
abstract: Free light chains (FLCs) are the most commonly detected paraproteins in chronic lymphocytic leukemia (CLL). We examined the types of FLC abnormalities and prognostic utility of the FLC assay compared with standard prognostic biomarkers in a prospective cohort of 339 patients with newly diagnosed CLL. Three types of FLC abnormalities were identified: monoclonal elevated FLC (elevated κ and/or λ with abnormal FLC ratio), polyclonal elevated FLC (elevated κ and/or λ with normal FLC ratio), and ratio-only FLC abnormality (normal range κ and λ with abnormal FLC ratio). One hundred sixty-five patients (49%) had a FLC abnormality with approximately equal distribution among monoclonal elevation, polyclonal elevation, and ratio-only abnormality. All FLC abnormalities were associated with poor time to first treatment: monoclonal FLC (hazard ratio [HR], 4.99; 95% confidence interval [CI], 2.94-8.48), polyclonal FLC (HR, 2.40; 95% CI, 1.24-4.64), ratio-only FLC (HR, 2.57; 95% CI, 1.40-4.69). Monoclonal FLC and polyclonal FLC were associated with poor overall survival compared with patients with normal FLC. Results remained significant after adjusting for Rai stage. The FLC assay is a simple, widely available clinical test with similar prognostic utility as routinely used prognostic biomarkers for CLL. Among persons with FLC abnormalities, the type of abnormality affects prognostic significance.
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN 55905, USA. maurer.matthew@mayo.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Maurer
authors.forename: James R
authors.initials: JR
authors.lastname: Cerhan
authors.forename: Jerry A
authors.initials: JA
authors.lastname: Katzmann
authors.forename: Brian K
authors.initials: BK
authors.lastname: Link
authors.forename: Cristine
authors.initials: C
authors.lastname: Allmer
authors.forename: Clive S
authors.initials: CS
authors.lastname: Zent
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Call
authors.forename: Kari G
authors.initials: KG
authors.lastname: Rabe
authors.forename: Curtis A
authors.initials: CA
authors.lastname: Hanson
authors.forename: Neil E
authors.initials: NE
authors.lastname: Kay
authors.forename: Susan L
authors.initials: SL
authors.lastname: Slager
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Witzig
authors.forename: Tait D
authors.initials: TD
authors.lastname: Shanafelt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D002999:Clone Cells; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D007145:Immunoglobulin kappa-Chains / Q000097:blood*; D007146:Immunoglobulin lambda-Chains / Q000097:blood*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains