RT Book, Section
A1 Gertz, Morie A.
A1 Sher, Taimur
A1 Dispenzieri, Angela
A1 Buadi, Francis K.
A2 Kaushansky, Kenneth
A2 Prchal, Josef T.
A2 Burns, Linda J.
A2 Lichtman, Marshall A.
A2 Levi, Marcel
A2 Linch, David C.
SR Print(0)
ID 1180466663
T1 Immunoglobulin Light Chain Amyloidosis
T2 Williams Hematology, 10e
YR 2021
FD 2021
PB McGraw-Hill Education
PP New York, NY
SN 9781260464122
LK accessmedicine.mhmedical.com/content.aspx?aid=1180466663
RD 2024/04/19
AB SUMMARYImmunoglobulin  light-chain  (AL)  amyloidosis  should  be  considered  in  any  patient  presenting  with  nephrotic  range  proteinuria;  infiltrative  cardiomyopathy  or  heart  failure  with  preserved  ejection  fraction;  hepatomegaly  without  specific  imaging  findings;  peripheral  neuropathy,  particularly  if  a  monoclonal  protein  is  present;  and  any  patient  with  atypical  myeloma,  smoldering  myeloma,  or  monoclonal  gammopathy  of  undetermined  significance  (MGUS)  that  is  unwell.  When  a  patient  is  seen  with  a  compatible  syndrome,  the  patient  should  have  immunofixation  of  serum,  immunofixation  of  urine,  and  κ  and  λ  immunoglobulin  free  light  chains.  If  all  of  these  tests  are  normal,  it  is  less  likely  that  the  patient  has  immunoglobulin  light-chain  (AL)  amyloidosis.If  any  of  the  above  tests  are  positive,  further  investigation  for  amyloidosis  should  be  undertaken.  The  diagnostic  test  of  choice  is  subcutaneous  fat  aspiration.  The  second  would  be  a  marrow  biopsy.  With  those  two  tests,  83%  of  patients  will  have  a  positive  result  when  the  sample  is  stained  with  Congo  red  and  viewed  with  green  birefringence.All  patients  with  biopsy-proven  amyloidosis  should  have  the  deposits  analyzed  by  laser  capture  microdissection  mass  spectroscopy  to  definitively  classify  the  exact  protein  subunit  composing  the  amyloid.  This  technique  does  not  distinguish  between  systemic  and  localized  amyloidosis.The  prognosis  in  AL  amyloidosis  is  determined  by  three  tests:  (1)  the  NT-proBNP,  (2)  serum  troponin,  and  (3)  the  difference  between  the  involved  and  uninvolved  immunoglobulin  free  light  chains.  These  three  tests  can  be  combined  to  stage  the  patient.Treatment  of  AL  amyloidosis  is  either  traditional  systemic  chemotherapy  or  high-dose  chemotherapy  with  stem  cell  transplantation.  Fit  patients  would  be  expected  to  have  low  morbidity  with  this  modality  of  treatment.  The  majority  of  patients,  however,  will  not  be  candidates  for  transplantation  and  should  be  treated  with  traditional  systemic  chemotherapy;  and  the  combination  of  cyclophosphamide,  bortezomib,  and  dexamethasone  (CyBorD)  is  frequently  used.  Daratumumab  is  also  efficacious  in  AL  amyloidosis.