Kidney disease and plasma cell dyscrasias: ambiguous cases solved by serum free light chain dimerization analysis
Plasma cell dyscrasias (PCD) comprise a wide spectrum of disorders, which may adversely affect the kidney. However, in some PCD cases associated with kidney disease, the routine laboratory tests may be incapable to determine precisely the form of PCD, i.e., benign or malignant. Moreover, the kidney biopsy needed for precise diagnosis may be risky or declined. To overcome these limitations, we have developed and reported a new non-invasive technique based on serum free light chains (FLC) monomer (M) and dimer (D) pattern analysis (FLC MDPA), which allowed differentiation between malignant and benign PCD forms. The objective of our retrospective study was to demonstrate the utility of FLC MDPA in solving ten puzzling PCD cases complicated with kidney disease (patients 1–10).
Ten patients with uncertain form of PCD or with a questionable response to treatment were studied. In addition to routine laboratory tests and clinical evaluation of the PCD patients, our previously developed FLC MDPA in sera and biochemical amyloid typing in biopsy tissues were applied.
The FLC MDPA aided the diagnosis of the PCD underlying or accompanying the kidney disease in patients 1–5, and helped to interpret properly the response to treatment in patients 1, 6–10. The FLC MDPA findings were confirmed by a biochemical analysis of tissue amyloid deposits and subsequently by the outcome of these patients.
FLC MDPA is a non-invasive diagnostic test useful in the management of ambiguous cases of PCD associated with kidney disease.
KeywordsFree light chains Amyloidosis Kidney diseases
We would like to thank Dr. R. Kaplan for his invaluable advice and helpful discussion in the preparation of this manuscript.
Compliance with ethical standards
Conflict of interest
The authors have declared that no conflict of interest exists.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee at which the studies were conducted (IRB approval number 2982-16-SMC) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
For this type of study (retrospective), formal informed consent was not required.
- 8.Kaplan B, Ramirez-Alvarado M, Sikkink L, et al. Free light chains in plasma of patients with light chain amyloidosis and non-amyloid light chain deposition disease. High proportion and heterogeneity of disulfide-linked monoclonal free light chains as pathogenic features of amyloid disease. Br J Haematol. 2009;144:705–15.CrossRefGoogle Scholar
- 14.Bradwell AR. Serum free light chain analysis (plus Hevylite). 6th ed. Birmingham: The Binding Site Group Ltd; 2010.Google Scholar