Predictors of hematologic response and survival with stem cell transplantation in AL amyloidosis: A 25-year longitudinal study.

High-dose melphalan and stem cell transplantation (HDM/SCT) is an effective treatment for selected patients with AL amyloidosis. We report the long-term outcomes of 648 patients with AL amyloidosis treated with HDM/SCT over 25 years. Hematologic CR was achieved by 39% of patients. The median duration of hematologic CR was 12.3 years, and 45% of patients with a hematologic CR had no evidence of a recurrent plasma cell dyscrasia at 15 years after HDM/SCT. With a median follow-up interval of 8 years, the median event-free survival (EFS) and overall survival (OS) were 3.3 and 7.6 years, respectively. Patients with a hematologic CR had a median OS of 15 years, and 30% of these patients survived >20 years. On multivariable analysis, dFLC >180 mg/L and BM plasma cells >10% were independently associated with shorter EFS, whereas BNP >81 pg/mL, troponin I > 0.1 ng/mL, and serum creatinine >2.0 mg/dL were independently associated with shorter OS. We developed a prognostic score for EFS, which incorporated dFLC >180 mg/L and BMPC% >10% as adverse risk factors. Patients with low-risk (0 factors), intermediate-risk (1 factor), and high-risk (2 factors) disease had median EFS estimates of 5.3, 2.8, and 1.0 years, respectively (p < .001). The 100-day treatment-related mortality rate was 3% in the latest treatment period (2012-2021), and the 25-year risk of t-MDS/AML was 3%. We conclude that HDM/SCT induces durable hematologic responses and prolonged survival with improved safety in selected patients with AL amyloidosis.

Patient outcomes in light chain (AL) amyloidosis: The clock is ticking from symptoms to diagnosis.

INTRODUCTION: Symptomology of AL amyloidosis can be vague, with a broad range of manifestations and potential etiologies. We sought to determine whether time from initial patient-reported symptom onset to diagnosis was associated with survival. METHODS: The Boston University Amyloidosis Patient Database was queried for patients with AL amyloidosis who presented to the Center for initial evaluation from 2010 to 2015. RESULTS: A total of 324 patients with AL amyloidosis were evaluated for initial evaluation. The median time to diagnosis from initial symptom onset was 7.1 months (range, 0-61). At data cutoff, 60.2% (n = 195) of patients were alive; of those, the majority were diagnosed <6 months from initial symptoms (52.3%, n = 102). In contrast, time to diagnosis from symptom onset was >6 months in 63.6% (n = 82) of patients who did not survive at the time of data cutoff (P = .0005). Survival analysis of time from diagnosis to death or data cutoff stratified by time from patient-reported symptom onset to diagnosis (<6, 6-12, and >12 months) showed significant differences among groups (P = .001). Additionally, multivariable regression demonstrated that an increase in time from self-reported symptom onset to diagnosis was significantly associated with an increased risk of death (HR = 1.02, 95% CI = 1.01-1.04, P = .002). CONCLUSION: These results support the importance of early diagnosis for patients with AL amyloidosis.

Factors affecting the accuracy of amyloidosis identification and referral to a specialty centre.

OBJECTIVE: Diagnostic algorithms for amyloidosis have evolved over the past decade, particularly with the incorporation of imaging-based techniques to detect amyloid cardiomyopathy. We sought to identify the key sources of amyloidosis misidentification in the community, which lead to false positive referrals to a tertiary centre. METHODS: We conducted a retrospective review of all referrals to the Amyloidosis Centre from 2010 to 2021 and identified cases lacking amyloid pathology upon final adjudication after extensive assessment at the centre. Factors for false positive referrals were examined. RESULTS: Among 2409 referrals of suspected amyloidosis, 147 (6%) demonstrated an absence of amyloid pathology. This percentage increased over time from 4% in 2010 to 13% in 2021. False positive referrals consisted of more people of colour. The most frequent source of inaccuracy was the erroneous staining of tissue specimens with Congo red, followed by suggestive findings on cardiac imaging. In recent years, misinterpretation of 99mtechnetium- pyrophosphate scintigraphy emerged as a major source of false positive referrals. CONCLUSION: Recognising these potential sources of diagnostic error in the workup of amyloidosis can improve patient care. Referral to a centre of excellence for amyloidosis helps confirm an accurate diagnosis and avoid mistreatment.

Marked progress in AL amyloidosis survival: a 40-year longitudinal natural history study.

The recent decades have ushered in considerable advancements in the diagnosis and treatment of systemic light chain (AL) amyloidosis. As disease outcomes improve, AL amyloidosis-unrelated factors may impact mortality. In this study, we evaluated survival trends and primary causes of death among 2337 individuals with AL amyloidosis referred to the Boston University Amyloidosis Center. Outcomes were analyzed according to date of diagnosis: 1980-1989 (era 1), 1990-1999 (era 2), 2000-2009 (era 3), and 2010-2019 (era 4). Overall survival increased steadily with median values of 1.4, 2.6, 3.3, and 4.6 years for eras 1-4, respectively (P < 0.001). Six-month mortality decreased over time from 23% to 13%. Wide gaps in survival persisted amid patient subgroups; those with age at diagnosis ≥70 years had marginal improvements over time. Most deaths were attributable to disease-related factors, with cardiac failure (32%) and sudden unexpected death (23%) being the leading causes. AL amyloidosis-unrelated mortality increased across eras (from 3% to 16% of deaths) and with longer-term survival (29% of deaths occurring >10 years after diagnosis). Under changing standards of care, survival improved and early mortality declined over the last 40 years. These findings support a more optimistic outlook for patients with AL amyloidosis.

A new era of amyloidosis: the trends at a major US referral centre.

Objective: To characterize the changing spectrum of amyloidosis classes, as well as patient demographics, at a major US referral centre. Patients and methods: A retrospective analysis was conducted of all referrals to the Amyloidosis Centre at Boston University and Boston Medical Centre over the last 3 decades. Results: A total of 3987 new patients with amyloidosis were evaluated between 1990 and 2018 with the average number of new cases per year increasing 2.5-fold during this period. Systemic immunoglobulin light-chain (AL) amyloidosis decreased in proportion with each decade from 77% to 69% to 50% of new cases. Meanwhile, ATTR amyloidosis increased from 12% to 16% to 29%, predominately due to more diagnosis of ATTRwt and ATTRV122I amyloidosis. Gender and race profile differences, while changing over the observed time period, persisted among amyloidosis patients. Conclusion: Amyloid diseases are more widely recognized and classes of amyloidosis, including ATTRwt and ATTRV122I, once considered rare are now increasingly diagnosed. These data likely reflect a national trend of increased amyloidosis awareness facilitated by accessible diagnostic approaches, emerging treatments, and coordinated educational initiatives. ClinicalTrials.gov identifier: NCT00898235.

Outcomes of patients with AL amyloidosis and low serum free light chain levels at diagnosis.

Serum free light chains (sFLC) are independent prognostic markers of disease in light chain (AL) amyloidosis, and are used in the haematologic response criteria for treatment. However, up to 20% of patients have low sFLCs at diagnosis, with a difference between involved and uninvolved free light chains (dFLC) of less than 50 mg/L, making responses to treatment difficult to evaluate. In order to characterize this distinct subgroup of patients, we retrospectively analyzed 123 AL amyloidosis patients with dFLC <50 mg/L who were diagnosed between 2002 and 2013. The majority (n = 117) were treated for their AL amyloidosis, with over half (n = 68) receiving high-dose melphalan and autologous stem cell transplantation as first-line therapy. Overall they had a prolonged median survival of 9.2 years with less cardiac involvement (30%) and more renal involvement (76%). We also evaluated the newly proposed low dFLC partial response (PR) criteria, defined as a dFLC <10 mg/L if the initial dFLC 20-50 mg/L. The 14 patients with low dFLC PR had improved survival and organ responses compared with patients with no haematologic response. However, one-third of patients (n = 41) had an initial dFLC <20 mg/L so could not be evaluated. More sensitive methods of monitoring response to treatment for this subgroup population are still needed.