Early reduction of serum-free light chains associates with renal recovery in myeloma kidney

J Am Soc Nephrol. 2011 Jun;22(6):1129-36. doi: 10.1681/ASN.2010080857. Epub 2011 Apr 21.

Abstract

Myeloma kidney is the major cause of severe irreversible renal failure in patients with multiple myeloma. This tubulointerstitial injury is a direct consequence of high concentrations of circulating monoclonal free light chains (FLCs) produced by a clonal expansion of plasma cells. Early reduction of serum FLCs associates with renal recovery, but the target threshold of reduction to facilitate renal recovery is unknown. To determine the relationship between the achieved FLC reduction and renal recovery, we identified 39 patients with biopsy-proven myeloma kidney, the majority of whom had severe renal failure at presentation (median estimated GFR 9 ml/min per 1.73 m²). In a multivariable analysis incorporating demographic, hematologic, and renal variables, only the achieved FLC reduction significantly predicted renal recovery (P = 0.003). The relationship between renal recovery and FLC reduction was linear with no absolute threshold for FLC reduction. A 60% reduction in FLCs by day 21 associated with recovery of renal function for 80% of the population. Patient survival strongly associated with renal recovery: the median survival was 42.7 months (range 0 to 80) among those who recovered function compared with 7.8 months (range 0 to 54) among those who did not (P < 0.02). Cox-regression analysis demonstrated that the first presentation of myeloma, the kappa isotype of FLC, and renal recovery were independent predictors of survival. In conclusion, recovery of renal function in myeloma kidney depends on early reduction of serum FLCs, and this recovery associates with a significant survival advantage.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biopsy
  • Drug Therapy
  • Female
  • Humans
  • Immunoglobulin Light Chains / blood*
  • Kidney / pathology
  • Kidney / physiology*
  • Kidney Neoplasms / complications*
  • Kidney Neoplasms / drug therapy
  • Kidney Neoplasms / mortality
  • Male
  • Middle Aged
  • Multiple Myeloma / complications*
  • Multiple Myeloma / drug therapy
  • Multiple Myeloma / mortality
  • Multivariate Analysis
  • Recovery of Function / physiology*
  • Regression Analysis
  • Renal Dialysis
  • Renal Insufficiency / etiology*
  • Renal Insufficiency / mortality
  • Renal Insufficiency / therapy*
  • Retrospective Studies
  • Survival Rate

Substances

  • Immunoglobulin Light Chains