title: Oligoclonal bands and immunoglobulin isotype switch during monitoring of patients with multiple myeloma and autologous hematopoietic cell transplantation: a 16-year experience.
abstract: BACKGROUND
  Over the last 20 years, high dose therapy followed by hemopoietic stem cell transplantation has been employed in patients with multiple myeloma (MM). During 16 years of follow-up, the degree of tumor response and survival in 238 patients with autologous stem cell transplantation (ASCT) and changes in the serum protein electrophoretic pattern were analyzed.
  
  
  METHODS
  Agarose gel electrophoresis with densitometric analysis and immunofixation were performed to evaluate serum monoclonal protein. IgM, IgA, IgG and beta(2)-microglobulin (beta2M) were quantitated. Urine protein electrophoresis with IF was performed on cellulose acetate gel using colloidal silver staining without concentrating.
  
  
  RESULTS
  After 34 months of follow-up (range 1-160 months), eight patients (3.4%) showed a distinct monoclonal protein band that was different from their original isotype switch. This was observed to be a transient phenomenon (22.2 months). Thirty-seven patients (15.5%) developed oligoclonal bands (OB) between the first and the twentieth month after ASCT (mean 4.4 months), which persisted for 7.9 months (1-36 months). The mean overall survival time was statistically different (p<0.05) between the group with OB and the group without them. Mean values of serum albumin, beta2M, and non-involved immunoglobulins did not show statistical differences.
  
  
  CONCLUSIONS
  The occurrence of OB could be a potential favorable prognostic marker after transplantation due to the prolonged survival observed. Close follow-up of anomalous protein bands, either in serum or urine, is essential due to the additional difficulty in interpretation when the therapeutic response and evolution are evaluated.
authors.affiliation: Department of Clinical Biochemistry, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina. marielalejandre@hotmail.com
authors.forename: Mariel Emilce
authors.initials: ME
authors.lastname: Alejandre
authors.forename: Leticia Bibiana
authors.initials: LB
authors.lastname: Madalena
authors.forename: Miguel Arturo
authors.initials: MA
authors.lastname: Pavlovsky
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Facio
authors.forename: Claudia
authors.initials: C
authors.lastname: Corrado
authors.forename: Gustavo
authors.initials: G
authors.lastname: Milone
authors.forename: Pablo Diego
authors.initials: PD
authors.lastname: Bresciani
authors.forename: Susana Alicia
authors.initials: SA
authors.lastname: Fraind
authors.forename: Santiago
authors.initials: S
authors.lastname: Pavlovsky
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Pizzolato
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003720:Densitometry; D004587:Electrophoresis, Agar Gel; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000097:blood*; D007525:Isoelectric Focusing; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D043025:Oligoclonal Bands / Q000097:blood*; D011379:Prognosis; D014182:Transplantation, Autologous
chemical_list: D015415:Biomarkers; D007132:Immunoglobulin Isotypes; D043025:Oligoclonal Bands