Absolute values of immunoglobulin free light chains are prognostic in patients with primary systemic amyloidosis undergoing peripheral blood stem cell transplantation.
The immunoglobulin free light chain (FLC) is the precursor protein of amyloid in primary systemic amyloidosis (AL). Historically, the ability to monitor the amyloid protein precursor protein has been crude. We evaluated the utility of the FLC assay in a retrospective analysis of patients with AL undergoing peripheral blood stem cell transplantation (PBSCT). Ninety-three such patients had serial FLC measurements performed. The prognostic effects of the initial concentration and the extent of reduction of monoclonal FLC on survival were studied. There was a significantly higher risk of death in patients with higher baseline FLC (hazard ratio 2.6, P < .04). Baseline FLC correlated with serum cardiac troponin levels, and higher FLC levels were associated with more organs involved by amyloid, suggesting that high FLC levels may be associated with more advanced disease. The percent FLC reduction did not predict for survival, but the absolute level of FLC achieved after therapy did. Normalization of FLC level after PBSCT predicted for both organ response and complete hematologic response. Achievement of FLC response was a better predictor of survival than achievement of complete hematologic response or normalization of the FLC ratio. FLC measurements both before and after PBSCT are important predictors of patient outcome.
Dispenzieri
Angela
A
Division of Hematology and Internal Medicine, Mayo Clinic, Rochester, MN, USA. dispenzieri.angela@mayo.edu
Lacy
Martha Q
MQ
Katzmann
Jerry A
JA
Rajkumar
S Vincent
SV
Abraham
Roshini S
RS
Hayman
Suzanne R
SR
Kumar
Shaji K
SK
Clark
Raynell
R
Kyle
Robert A
RA
Litzow
Mark R
MR
Inwards
David J
DJ
Ansell
Stephen M
SM
Micallef
Ivana M
IM
Porrata
Luis F
LF
Elliott
Michelle A
MA
Johnston
Patrick B
PB
Greipp
Philip R
PR
Witzig
Thomas E
TE
Zeldenrust
Steven R
SR
Russell
Stephen J
SJ
Gastineau
Dennis
D
Gertz
Morie A
MA
D000328:Adult; D000368:Aged; D000682:Amyloid / Q000097:blood*; D000686:Amyloidosis / Q000097:blood* / Q000401:mortality / Q000628:therapy; D015415:Biomarkers / Q000097:blood; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D008297:Male; D008875:Middle Aged; D036102:Peripheral Blood Stem Cell Transplantation; D011237:Predictive Value of Tests; D020127:Recovery of Function; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
D000682:Amyloid; D015415:Biomarkers; D007147:Immunoglobulin Light Chains