Serum free light chains and oligoclonal bands in patients with multiple myeloma and autologous stem cell transplantation.
BACKGROUND
To establish stringent complete remission (SCR) in patients with multiple myeloma (MM), it is currently recommended to obtain a normal serum free light chains (sFLC) ratio. The appearance of serum oligoclonal bands (OB) after autologous stem cell transplantation (ASCT) is considered a favorable prognostic factor. The objective of this study was to examine sFLC for assessing SCR in patients with MM, and ASCT with OB. We also examined how capillary electrophoresis (CE) compares with agarose gel electrophoresis (Aga) in identifying oligoclonal bands.


METHODS
Out of 238 patients studied in our institution between April 1992 and December 2008 a serum protein electrophoresis (SPE) was performed by means of CE and sFLC determination on 37 patients with MM in complete remission (CR), ASCT and OB presence were assigned by conventional Aga electrophoresis and IF.


RESULTS
Statistically significant differences (SSD) were found when comparing CE vs. Aga, regarding BO visualization in SPE, favoring the latter. In connection with sFLC, the group of patients with an abnormal ratio presented elevated values in the γ-globulin zone of the SPE, whereas the group of patients with a normal ratio of sFLC presented with normal values resulting in SSD between the groups.


CONCLUSIONS
It is essential to perform immunofixation to certify the presence of OB, especially if CE is used as it is difficult to distinguish them using this method. A normal sFLC was observed in most of the patients with OB and normal values of the SPE γ-globulin zone. The above-mentioned information might demonstrate a limitation of sFLC test in SCR evaluation for patients with MM, ASCT and CR if OB has been detected.
Department of Clinical Biochemistry, INFIBIOC, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina. marielalejandre@hotmail.com
Mariel Emilce
ME
Alejandre
Miguel Arturo
MA
Pavlovsky
Guillermina
G
Remaggi
Claudia
C
Corrado
Isolda
I
Fernandez
Gustavo
G
Milone
Astrid
A
Pavlovsky
Leticia
L
Madalena
Marcela
M
Pandolfo
María Laura
ML
Facio
Pablo
P
Bresciani
Santiago
S
Pavlovsky
Marco A
MA
Pizzolato
D000328:Adult; D000368:Aged; D019075:Electrophoresis, Capillary; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000601:surgery*; D043025:Oligoclonal Bands / Q000097:blood*; D033581:Stem Cell Transplantation; D014182:Transplantation, Autologous
D007147:Immunoglobulin Light Chains; D043025:Oligoclonal Bands