Abstract
There is a possibility that renal dysfunction may potentially reduce the diagnostic power of the laboratory parameters Tn, NT-proBNP and sFLC levels, used in the current prognostic classification of AL amyloidosis and the diagnosis of heart involvement by amyloid. In this study, the impact of lowering the eGFR value on the usefulness of these parameters in the prognosis and diagnosis of the presence of amyloid in the myocardium was assessed in a group of 71 patients with newly diagnosed primary amyloidosis. The assessment of diagnostic power of laboratory parameters was performed on the entire study group, and in the ranges of eGFR ≥ 60 and < 60 mL/min/1.73 m2. It has been proven that, with a decrease in the eGFR value, the concentrations of NT-proBNP and the κ uninvolved light chains increase significantly (p < 0.001). To assess the diagnostic power of laboratory parameters used in the diagnosis of myocardial involvement in patients with AL amyloidosis, an ROC analysis was performed. The highest values of AUC were obtained for the NT-proBNP concentration (AUC = 0.906). The lowest values of the AUC and Youden’s index were obtained for the dFLC values (AUC = 0.723), and involved κ FLC concentration (AUC = 0.613). For all compared parameters, the smallest values of the AUC were obtained for eGFR (<60 mL/min/1.73 m2). It seems that the most suitable cardiac parameter used in the prognostic classification of AL amyloidosis, independent of renal function, is TnI. It should be noted that a concentration of involved λ chains hada higher diagnostic power to assess the heart involvement, compared to the routinely used “cardiac parameters”, TnI and NT-proBNP. It can therefore be an additional parameter used to assess the presence of amyloid in the myocardium. A decrease in eGFR value influenced the change in the diagnostic cut-off points of the most analyzed laboratory parameters. Finally, it is concluded that lowering the eGFR value reduces the utility of laboratory parameters used in the prognostic classification of AL amyloidosis.
Highlights
Immunoglobulin light chain amyloidosis (AL) is a neoplastic disease in which the amyloid fibers are made of κ or λ immunoglobulin free light chains (FLC), or its fragments, produced by a clone of plasmacytes or lymphoplasmacytes
Authors of numerous studies have repeatedly pointed to the fact that both NT-proBNP and TnI concentrations, as well as sFLC concentrations, dFLC value, and κ/λ concentration ratio, depend on the kidney function and the eGFR values [1,10,18,19,20,21]
It is pointed out that there is a necessity to perform more detailed analyses assessing the influence of renal dysfunction on the usefulness and diagnostic power of parameters used in the currently applicable prognostic classification of AL amyloidosis
Summary
Immunoglobulin light chain amyloidosis (AL) is a neoplastic disease in which the amyloid fibers are made of κ or λ immunoglobulin free light chains (FLC), or its fragments, produced by a clone of plasmacytes or lymphoplasmacytes. Cardiac involvement is a major adverse prognostic factor in AL amyloidosis, since 75% of deaths in this group of patients are caused by heart failure or arrhythmias due to amyloid fibril deposition. The currently applicable prognostic classification of AL amyloidosis according to Kumar et al is based on biochemical parameters assessing the myocardial function and damage degree (the concentration of troponin (Tn) and the N-terminal fragment of the B-type natriuretic peptide (NT-proBNP)), and the difference between the concentration of FLCs involved and uninvolved in the neoplastic process (dFLC) value [4,5,6]. The currently applicable prognostic classification does not consider the different cut-off points of concentrations of laboratory parameters in patients with normal and impaired renal function. There is a possibility that renal dysfunction may potentially reduce the diagnostic power used to assess amyloid deposits in the heart [7,8,9,10,11,12]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
