RT Book, Section
A1 Dirkx, Tonja C.
A1 Woodell, Tyler B.
A2 Papadakis, Maxine A.
A2 McPhee, Stephen J.
A2 Rabow, Michael W.
A2 McQuaid, Kenneth R.
SR Print(0)
ID 1184183507
T1 Plasma Cell Myeloma
T2 Current Medical Diagnosis & Treatment 2022
YR 2022
FD 2022
PB McGraw-Hill Education
PP New York, NY
SN 9781264269389
LK accessmedicine.mhmedical.com/content.aspx?aid=1184183507
RD 2024/04/25
AB Plasma  cell  myeloma  is  a  malignancy  of  plasma  cells  (see  Chapter  13)  that  can  cause  a  variety  of  renal  disorders.  Injury  is  due  to  the  toxic  effects  of  monoclonal  immunoglobulins  or  light  chain  components  produced  by  plasma  cells.  “Myeloma  kidney”  (formally  called  cast  nephropathy)  is  the  most  common  kidney  disease  in  plasma  cell  myeloma  and  occurs  when  light  chains  (Bence  Jones  protein)  in  the  urine  cause  renal  toxicity  and  tubular  obstruction  by  precipitating  in  the  distal  tubules.  Plasma  cell  myeloma  may  also  cause  Fanconi  syndrome,  a  type  2  proximal  renal  tubular  acidosis  characterized  by  hypophosphatemia  and  inappropriate  glycosuria.  Proteinuria  in  “myeloma  kidney”  is  exclusively  tubular;  hence,  urine  dipstick  findings  are  minimal  since  glomerular  proteinuria  is  not  present.  Hypercalcemia  and  hyperuricemia  are  frequently  seen.  Glomerular  amyloidosis  with  nephrotic  syndrome  can  develop  in  patients  with  plasma  cell  myeloma;  in  these  patients,  urine  dipstick  is  positive  due  to  glomerular  epithelial  cell  foot  process  effacement  and  albumin  “spilling”  into  the  Bowman  capsule;  hematuria  may  or  may  not  be  present.  Other  conditions  resulting  in  kidney  dysfunction  include  plasma  cell  infiltration  of  the  renal  parenchyma  and  hyperviscosity  syndrome  compromising  renal  blood  flow.  The  presence  of  myeloma-related  kidney  disease  does  not  itself  preclude  use  of  contrast  dye  for  imaging  studies;  standard  precautions  for  the  use  of  intravenous  contrast  and  gadolinium  in  patients  with  reduced  GFR  apply  to  patients  with  myeloma-related  kidney  disease.  Therapy  for  AKI  (see  Acute  Kidney  Injury,  above)  attributed  to  plasma  cell  myeloma  includes  correction  of  hypercalcemia;  volume  repletion;  and  chemotherapy  for  the  underlying  malignancy,  typically  with  bortezomib-based  agents.  Plasmapheresis  has  been  proposed  to  reduce  the  burden  of  circulating  monoclonal  proteins,  but  results  have  been  equivocal  and  its  use  is  controversial.