title: Monoclonal and polyclonal gammopathy measured by serum free light chain and immunofixation subdivide the clinical outcomes of diffuse large B-cell lymphoma according to molecular classification.
abstract: Elevated serum free light chain (FLC) is known to be an adverse prognostic factor for diffuse large B-cell lymphoma (DLBCL). We hypothesized that monoclonal gammopathy (MG; elevated kappa [κ] or lambda [λ] FLC with an abnormal κ/λ ratio or a positive IF [immunofixation]) and polyclonal gammopathy (PG; elevated κ and/or λ FLC with a normal κ/λ ratio and a negative IF) would have different clinical outcome according to the molecular classification of DLBCL. In addition, MG would be a poor prognostic factor in patients with activated B-cell like type of DLBCL. Molecular classification of DLBCL, such as germinal center B-cell (GCB) type and non-GCB type, was performed according to the Hans algorithm. Among 175 newly diagnosed DLBCL patients, 96 (54.9 %) patients had an elevated FLC. MG and PG were observed in 34 and 68 patients, respectively. The 2-year overall survival (OS) and event-free survival (EFS) rates were 79.0 % and 71.6 %, respectively. In multivariate analysis, high-intermediate/high International Prognostic Index score and elevated FLC were significant for the OS (P = 0.002, P = 0.005, respectively) and EFS (P < 0.002, P = 0.010, respectively). MG and PG were also associated with inferior OS (P = 0.002, P = 0.011, respectively) and EFS (P = 0.002, P = 0.013, respectively). Ninety-six patients from a total 133 evaluable patients were classified to the non-GCB type. Patients with PG showed inferior clinical outcome for OS and EFS in patients with the GCB type (P = 0.006, P = 0.035, respectively). MG was a significant poor prognostic factor for OS and EFS in patients with the non-GCB type (P = 0.017, P = 0.004, respectively). MG was a poor prognostic maker in patients with the non-GCB type and PG was a poor prognostic indicator for the GCB type of DLBCL who were treated with R-CHOP.
authors.affiliation: Division of Hematology, Department of Internal Medicine, Gangnam Severance Hospital, Seoul, South Korea.
authors.forename: Yu Ri
authors.initials: YR
authors.lastname: Kim
authors.forename: Soo-Jeong
authors.initials: SJ
authors.lastname: Kim
authors.forename: June-Won
authors.initials: JW
authors.lastname: Cheong
authors.forename: Yundeok
authors.initials: Y
authors.lastname: Kim
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Jang
authors.forename: Jung Yeon
authors.initials: JY
authors.lastname: Lee
authors.forename: Yoo Hong
authors.initials: YH
authors.lastname: Min
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Song
authors.forename: Woo Ick
authors.initials: WI
authors.lastname: Yang
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood* / Q000145:classification; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood* / Q000145:classification; D016403:Lymphoma, Large B-Cell, Diffuse / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D007147:Immunoglobulin Light Chains