LAUSR

The interpretation of N-terminal-pro hormone brain natriuretic peptide (NT-ProBNP) and Troponin T levels can be difficult in the presence of kidney dysfunction, as they are renally excreted [1, 2]. We evaluated the prognostic value of these biomarkers in patients with light chain (AL) amyloidosis and kidney dysfunction. We identified patients with a diagnosis of AL amyloidosis according the consensus criteria [3] who were transplanted between March 1996 and August 2017 and who had a Cr > 1 mg/dl and a glomerular filtration rate (GFR) ≤ 90. Cardiac biomarkers and Mayo 2012 stage [4] were recorded before autologous stem cell transplantation (ASCT). Response was evaluated at day 100 post ASCT [5]. The study was approved by the Mayo Clinic Institutional Review Board. Patients were divided into three groups based on the GFR: Group 1 (>60–90 ml/min), Group 2 (30–60 ml/min), and Group 3 (<30 ml/min). We evaluated overall survival (OS) based on the cardiac biomarkers levels at different cutoffs (data not shown). We concluded three groups: Group 1 with NT-ProBNP ≤500 pg/ml, Group 2 with NTProBNP >500–≤2500 pg/ml, and Group 3 with NT-ProBNP >2500 pg/ml. For Troponin T: Group 1 with Troponin T ≤0.01 μg/L, Group 2 with levels >0.01–≤0.05 μg/L, and Group 3 with levels >0.05 μg/L. The median and interquartile range were described, and the Wilcoxon rank-sum test was used for continuous variables and for categorical variables, the Chi-square test was used. Progression-free survival (PFS) was defined as the time from ASCT to relapse or death and OS was defined from ASCT to death of any cause. Kaplan–Meier method was used for survival analysis and univariate and multivariate analysis for PFS and OS were done. We evaluated each cardiac biomarker alone (Model 1) and as a single variable of having (NTProBNP >2500 pg/ml) or (Troponin T >0.05 μg/L) (Model 2). All tests were two-sided and a P-value of <0.05 was considered significant. The analysis was done using JMP software (SAS Institute, Cary, NC). We identified 514 patients and the baseline characteristics are displayed in Supplementary Table 1A. The median age at diagnosis was 59 years (53–65), median Cr was 1.2 mg/dl (1–1.4), and the median GFR was 65 (47–77). Most patients (285,55%) were in GFR Group 1, followed by 179 (35%) in GFR Group 2, and 50 (10%) in GFR Group 3. For NT-ProBNP, 186 (44%) were in NT-ProBNP Group 1, 125 (29%) were in Group 2, and 115 (27%) were in Group 3. These authors contributed equally: Abdullah S. Al Saleh, Harsh Parmar