title: Characteristics of unexpected protein bands in multiple myeloma patients after autologous stem cell transplantation.
abstract: OBJECTIVE
  The aim of this study is to investigate the characteristics of unexpected protein bands (UPBs) in patients with multiple myeloma (MM).
  
  
  METHODS
  Individuals diagnosed with MM (n=193) were enrolled. Their medical records and IFE patterns were reviewed.
  
  
  RESULTS
  Of the patients that underwent ASCT, 54% developed UPBs. The median time for UPB appearance and duration was 1.8 and 5.7months, respectively. IFE revealed 74.1% of UPBs to be of the immunoglobulin G type and 72.2% to be of the κ-type. At UPB appearance, 42.6% of patients were defined as sCR or CR, and 50.0% of the patients satisfying the CR criteria had an abnormal FLC ratio. Of the patients who developed UPBs, five relapsed. Among these, four patients showed disappearance of the previous IFE oligoclonality and reappearance of the original paraprotein at relapse.
  
  
  CONCLUSIONS
  Close follow-up of UPBs is critical for evaluating MM therapeutic response and disease progression. The presence of monoclonal bands may indicate relapse of disease, but in the vast majority of cases with UPBs, it does not; instead, it most likely represents a transient phenomenon caused by the immune response.
authors.affiliation: Departments of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Soo-Kyung
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Departments of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Tae-Dong
authors.initials: TD
authors.lastname: Jeong
authors.affiliation: Departments of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: So Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Departments of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea. Electronic address: wlee1@amc.seoul.kr.
authors.forename: Woochang
authors.initials: W
authors.lastname: Lee
authors.affiliation: Departments of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Sail
authors.initials: S
authors.lastname: Chun
authors.affiliation: Departments of Oncology, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Cheol Won
authors.initials: CW
authors.lastname: Suh
authors.affiliation: Departments of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Won-Ki
authors.initials: WK
authors.lastname: Min
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000378:metabolism; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000378:metabolism* / Q000628:therapy*; D011506:Proteins / Q000378:metabolism*; D033581:Stem Cell Transplantation; D014182:Transplantation, Autologous
chemical_list: D006454:Hemoglobins; D007147:Immunoglobulin Light Chains; D011506:Proteins; D003404:Creatinine; D002118:Calcium
keywords: Free light chain ratio; Immunofixation electrophoresis; Multiple myeloma; Unexpected protein band