title: The risk of renal disease is increased in lambda myeloma with bone marrow amyloid deposits.
abstract: BACKGROUND
  Light chain amyloidosis (AL) is a rare deposition disease and is present in 10-15% of patients with myeloma (MM). In contrast to symptomatic AL in MM, presence of bone marrow (BM) amyloid deposits (AD) in MM is not connected to kidney damage. Renal AD but not BM-AD occur mostly in MM with lambda paraprotein (lambda MM).
  
  
  METHODS
  We investigated amyloid presence in BM clots taken at diagnosis in 84 patients with symptomatic MM and compared disease characteristics in MM with kappa paraprotein (kappa MM)/lambda MM with and without BM-AD.
  
  
  RESULTS
  Lambda MM with BM-AD was compared with kappa MM without BM-AD, kappa MM with BM-AD, and lambda MM without BM-AD: lambda MM with BM-AD patients had a significantly higher mean creatinine level (4.23 mg/dL vs 1.69, 1.14, and 1.28 mg/dL, respectively) and a higher proportion presented with severe kidney failure (6/11 [55%] vs 6/32 [19%], 1/22 [5%], and 3/19 [16%], respectively). Proteinuria was more common in lambda MM with BM-AD patients compared with kappa MM without BM-AD patients (8/11 [73%] vs 5/32 [16%], respectively).
  
  
  CONCLUSIONS
  Kidney damage was more common in lambda MM with BM-AD indicating presence of renal AD.
authors.affiliation: Department of Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kozlowski
authors.affiliation: Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden; Clinical Epidemiology Unit, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden; Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Scott
authors.initials: S
authors.lastname: Montgomery
authors.affiliation: Department of Transfusion Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden.
authors.forename: Rahel
authors.initials: R
authors.lastname: Befekadu
authors.affiliation: Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
authors.forename: Victoria
authors.initials: V
authors.lastname: Hahn-Strömberg
keywords: amyloidosis; neoplasms; plasma cells; proteinuria; renal insufficiency