The association of serum-free light-chain levels with markers of renal function

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Erdem B. K., Davran F., YILMAZ V. T., ÇETİNKAYA R., Akbas H.

RENAL FAILURE, vol.37, no.6, pp.1057-1060, 2015 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 37 Issue: 6
  • Publication Date: 2015
  • Doi Number: 10.3109/0886022x.2015.1052980
  • Journal Name: RENAL FAILURE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1057-1060
  • Keywords: Kappa sFLC, lambda sFLC, renal function, serum-free light chains, sFLC ratios, CATABOLISM, KIDNEY
  • Akdeniz University Affiliated: Yes


Background: The kidney is often affected in plasma cell dyscrasias, usually due to the effects of nephrotoxic monoclonal-free light chains. Renal failure due to a monoclonal gammopathy may be detected by the highly sensitive serum-free light-chain (sFLC) ratio yet missed by electrophoretic assays. The aim of this study was to assess sFLC levels in relation to markers of renal function. Methods: Five-hundred thirteen patients were included in this study. sFLC levels were measured by Freelite(R) (The Binding Site Group Ltd, Birmingham, UK) assay using the BNII nephelometer (Siemens Diagnostics, Germany). Kappa/lambda (kappa/lambda) sFLC ratio was calculated. Serum creatinine levels were analyzed by modified Jaffe method in Cobas 8000 analyser. GFR was estimated by the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. Patients were assigned to two groups depending on their eGFR values: <= 60 mL/min/1.73m(2) (Group 1, n = 103) and >60 mL/min/1.73m2 (Group 2, n = 410). Data were expressed as median and min-max. All the statistical analyses were done with SPSS version 20.0 and a significance level of 0.05 was considered. Results: Serum kappa-FLC median value was 36.4 (5.62-16,000) mg/L, serum lambda-FLC was 21.7 (4.91-8770) mg/L, kappa/lambda sFLC ratio was 1.33 (0.01-3258) and serum creatinine was 1.56 (0.63-7.21) mg/dL in Group 1. Both lambda sFLC and kappa/lambda sFLC ratios were correlated with eGFR (r = -0.318, r = 0.198, p<0.05, respectively). We did not find any significant correlation between kappa/lambda sFLC ratio and eGFR in Group 2. Conclusions: We examined the association between sFLC concentrations and renal function. Our preliminary findings suggest that serum lambda-FLC might be considered as a useful marker for predicting renal function. Prospective studies are needed to clarify the usefulness of these parameters for identifying renal failure due to a monoclonal gammopathy.