title: Clinical significance of the appearance of abnormal protein band in patients with multiple myeloma.
abstract: Multiple myeloma (MM) is characterized by clonal expansion of malignant bone marrow cells producing a unique monoclonal immunoglobulin. The appearance of abnormal protein band (APB) in MM has been reported during follow-up. We aimed to evaluate the clinical characteristics and outcomes of patients with APB in a single center cohort. A total of 377 consecutive MM patients were treated at the Asan Medical Center between January 2002 and December 2012. We compared clinical characteristics and survival outcome between those with and without APB. Of the 377 patients, 34 (9 %) experienced APB. They comprised 18.2 % (27/148) of patients treated with autologous stem cell transplantation (ASCT) and 3.1 % (7/229) of those not receiving ASCT. APB occurred after a median of 7.9 months (range, 2.2-95.7 months) from diagnosis. Immunoglobulin isotypes at diagnosis were as follows: IgG (n = 10), IgA (n = 8), IgD (n = 5), free κ (n = 4), and free λ (n = 7). Nine patients experienced a second APB. With a median follow-up of 54.1 months, the median overall survival (OS) has not been reached in patients with APB and was 38.3 months in patients without (P < 0.001). Multivariate analysis indicated that the development of APB was a significant favorable prognostic factor for OS (hazard ratio 0.21; 95 % confidence interval 0.08-0.52). Serum β₂-microglobulin, albumin, creatinine, and ASCT were also independent prognostic factors for OS. Further investigation is required to establish the mechanisms underlying APB in MM.
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors.forename: Jae-Cheol
authors.initials: JC
authors.lastname: Jo
authors.forename: Dok Hyun
authors.initials: DH
authors.lastname: Yoon
authors.forename: Shin
authors.initials: S
authors.lastname: Kim
authors.forename: Kyoungmin
authors.initials: K
authors.lastname: Lee
authors.forename: Eun Hee
authors.initials: EH
authors.lastname: Kang
authors.forename: Seongsoo
authors.initials: S
authors.lastname: Jang
authors.forename: Chan-Jeoung
authors.initials: CJ
authors.lastname: Park
authors.forename: Hyun-Sook
authors.initials: HS
authors.lastname: Chi
authors.forename: Jooryung
authors.initials: J
authors.lastname: Huh
authors.forename: Chan-Sik
authors.initials: CS
authors.lastname: Park
authors.forename: Cheolwon
authors.initials: C
authors.lastname: Suh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001854:Bone Marrow Cells / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006942:Hypergammaglobulinemia / Q000209:etiology*; D017578:Immunoglobulin Class Switching; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D043025:Oligoclonal Bands / Q000032:analysis*; D010950:Plasma Cells / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D033581:Stem Cell Transplantation; D016019:Survival Analysis; D014182:Transplantation, Autologous
chemical_list: D043025:Oligoclonal Bands