Citations

AbstractThe immunoglobulin free light chain (FLC) is the precursor protein of amyloid in primary systemic amyloidosis (AL). Historically, the ability to monitor the amyloid protein precursor protein has been crude. We evaluated the utility of the FLC assay in a retrospective analysis of patients with AL undergoing peripheral blood stem cell transplantation (PBSCT). Ninety-three such patients had serial FLC measurements performed. The prognostic effects of the initial concentration and the extent of reduction of monoclonal FLC on survival were studied. There was a significantly higher risk of death in patients with higher baseline FLC (hazard ratio 2.6, P < .04). Baseline FLC correlated with serum cardiac troponin levels, and higher FLC levels were associated with more organs involved by amyloid, suggesting that high FLC levels may be associated with more advanced disease. The percent FLC reduction did not predict for survival, but the absolute level of FLC achieved after therapy did. Normalization of FLC level after PBSCT predicted for both organ response and complete hematologic response. Achievement of FLC response was a better predictor of survival than achievement of complete hematologic response or normalization of the FLC ratio. FLC measurements both before and after PBSCT are important predictors of patient outcome.

AbstractPrimary systemic amyloidosis (AL) is a fatal plasma cell disorder. Pilot data suggest survival is better in patients undergoing peripheral blood stem cell transplantation (PBSCT), but the selection process makes the apparent benefit suspect. We have reported that circulating cardiac biomarkers are the best predictors of survival outside of the transplantation setting. We now test whether cardiac troponins (cTnT and cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are prognostic in transplant recipients. In 98 patients with AL undergoing PBSCT, serum cardiac biomarkers were measured (cTnT, 98 patients; cTnI, 65 patients; and NT-proBNP, 63 patients). Elevated levels of cTnT, cTnI, and NT-proBNP were present in 14%, 43%, and 48% of patients, respectively. At 20 months median follow-up, median survival has not been reached for patients with values below the thresholds; in patients with values above the thresholds, median survival is 26.1 months, 66.1 months, and 66.1 months, respectively. Our previously reported risk systems incorporating these markers were also prognostic, notably the cTnT/NT-proBNP staging. Using this system, 49%, 38%, and 13% of patients were in stage I, stage II, and stage III, respectively. Determining levels of circulating biomarkers may be the most powerful tool for staging patients with AL undergoing PBSCT.

AbstractPrimary systemic amyloidosis (AL) is a plasma cell dyscrasia resulting in multisystem failure and death. High-dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) has been associated with higher response rates and seemingly higher overall survival than standard chemotherapy. Selection bias, however, confounds interpretation of these results. We performed a case-match-control study comparing overall survival of 63 AL patients undergoing transplantation with 63 patients not undergoing transplantation. Matching criteria included age, sex, time to presentation, left ventricular ejection fraction, serum creatinine, septal thickness, nerve involvement, 24-hour urine protein, and serum alkaline phosphatase. According to design, there was no difference between the groups with respect to sex (57% males), age (median, 53 years), left ventricular ejection fraction (65%), number of patients with peripheral nerve involvement (17%), cardiac interventricular septal wall thickness (12 mm), serum creatinine (1.1 mg/dL [97.24 μmol/L]), and bone marrow plasmacytosis (8%). Sixty-six patients have died (16 cases and 50 controls). For PBSCT and control groups, respectively, the 1-, 2-, and 4-year overall survival rates are 89% and 71%; 81% and 55%; and 71% and 41%. Outside a randomized clinical trial, these results present the strongest data supporting the role of PBSCT in selected patients with AL.

AbstractAutologous stem cell transplantation (ASCT) improves survival in patients with previously untreated multiple myeloma (MM) and relapsed, chemotherapy-sensitive, aggressive non-Hodgkin lymphoma (NHL). Lower relapse rates seen in allogeneic stem cell transplantation have been related to early absolute lymphocyte count (ALC) recovery as a manifestation of early graft-verus-tumor effect. In ASCT, the relation between ALC recovery and clinical outcomes in MM and NHL was not previously described. This is a retrospective study of patients with MM and NHL who underwent ASCT at the Mayo Clinic between 1987 and 1999. The ALC threshold was determined at 500 cells/μL on day 15 after ASCT. The study identified 126 patients with MM and 104 patients with NHL. The median overall survival (OS) and progression-free survival (PFS) times for patients with MM were significantly longer in patients with an ALC of 500 cells/μL or more than patients with an ALC of fewer than 500 cells/μL (33 vs 12 months,P &lt; .0001; 16 vs 8 months, P &lt; .0003, respectively). For patients with NHL, the median OS and PFS times were significantly longer in patients with an ALC of 500 cells/μL or more versus those with fewer than 500 cells/μL (not reached vs 6 months, P &lt; .0001; not reached vs 4 months,P &lt; .0001, respectively). Multivariate analysis demonstrated day 15 ALC to be an independent prognostic indicator for OS and PFS rates for both groups of patients. In conclusion, ALC is correlated with clinical outcome and requires further study.