Prognostic importance of the 6 min walk test in light chain (AL) amyloidosis

OBJECTIVES: In AL amyloidosis, organ response assessment is based on surrogates (eg, cardiac biomarkers). An objective functional test, such as the 6 min walk test (6MWT), capturing overall clinical improvement, is required. We aimed to evaluate the prognostic impact of the 6MWT at baseline and change following chemotherapy. METHODS: This study evaluated the outcomes of patients who enrolled in a prospective observational study at the UK National Amyloidosis Centre (2012-2017). Patients underwent comprehensive assessments inclusive of blood testing, echocardiogram and 6MWT at baseline and annually thereafter. RESULTS: In total, 799 patients were included within the study. Median baseline 6 min walk distance (6MWD) was 362 m (IQR: 231 m). 6MWD progressively decreased with worsening cardiac disease stage (458 m, 404 m, 331 m and 168 m for cardiac Mayo stages I, II, IIIa and IIIb, respectively (p<0.0001)). In patients with a baseline 6MWT of ≥350 m, the median overall survival was not reached (vs 30.0 (95% CI 23.2 to 36.8) months if <350 m and 5.0 (95% CI 2.8 to 7.2) months if unable to attempt 6MWT (p<0.0001). Following chemotherapy, only patients in a complete haematological response improved their 6MWD by 12 months (p=0.001). Improvement in 6MWD prolonged survival in patients with cardiac amyloidosis (p=0.005). CONCLUSION: The 6MWT is prognostic in AL amyloidosis. A baseline distance of ≥350 m independently predicts better survival. These data suggest that 6MWT has utility in AL amyloidosis for baseline prognosis and assessing response

The experience of hereditary apolipoprotein A-I amyloidosis at the UK National Amyloidosis Centre

INTRODUCTION: Hereditary apolipoprotein A-I (AApoAI) amyloidosis is a rare heterogeneous disease with variable age of onset and organ involvement. There are few series detailing the natural history and outcomes of solid organ transplantation across a range of causative APOA1 gene mutations. METHODS: We identified all patients with AApoAI amyloidosis who presented to the National Amyloidosis Centre (NAC) between 1986 and 2019. RESULTS: In total, 57 patients with 14 different APOA1 mutations were identified including 18 patients who underwent renal transplantation (5 combined liver-kidney (LKT) and 2 combined heart-kidney (HKT) transplants). Median age of presentation was 43 years and median time from presentation to referral was 3 (0-31 years). Involvement of the kidneys, liver and heart by amyloid was detected in 81%, 67% and 28% of patients, respectively. Renal amyloidosis was universal in association with the most commonly identified variant (Gly26Arg, n = 28). Across all variants, patients with renal amyloidosis had a median creatinine of 159 µmol/L and median urinary protein of 0.3 g/24 h at the time of diagnosis of AApoAI amyloidosis and median time from diagnosis to end-stage renal disease was 15.0 (95% CI: 10.0-20.0) years. Post-renal transplantation, median allograft survival was 22.0 (13.0-31.0) years. There was one early death following transplantation (infection-related at 2 months post-renal transplant) and no episodes of early rejection leading to graft failure. Liver transplantation led to regression of amyloid in all four cases in whom serial 123I-SAP scintigraphy was performed. CONCLUSIONS: AApoAI amyloidosis is a slowly progressive disease that is challenging to diagnose. The outcomes of transplantation are encouraging and graft survival is excellent

Longitudinal strain is an independent predictor of survival and response to therapy in patients with systemic AL amyloidosis

AIMS: Cardiac involvement, a major determinant of prognosis in AL (light-chain immunoglobulin) amyloidosis, is characterized by an impairment of longitudinal strain (LS%). We sought to evaluate the utility of LS% in a prospectively observed series of patients. METHODS AND RESULTS: A total of 915 serial newly diagnosed AL patients with comprehensive baseline assessments, inclusive of echocardiography, were included. A total of 628/915 (68.6%) patients had cardiac involvement. The LS% worsened with advancing cardiac stage with mean −21.1%, −17.1%, −12.9%, and −12.1% for stages I, II, IIIa, and IIIb, respectively (P < 0.0001). There was a highly significant worsening of overall survival (OS) with worsening LS% quartile: LS% ≤−16.2%: 80 months, −16.1% to −12.2%: 36 [95% confidence interval (CI) 20.9–51.1] months, −12.1% to −9.1%: 22 (95% CI 9.1–34.9) months, and ≥−9.0%: 5 (95% CI 3.2–6.8) months (P < 0.0001). Improvement in LS% was seen at 12 months in patients achieving a haematological complete response (CR) (median improvement from −13.8% to −14.9% in those with CR and difference between involved and uninvolved light chain <10 mg/L). Strain improvement was associated with improved OS (median not reached at 53 months vs. 72 months in patients without strain improvement, P = 0.007). Patients achieving an LS% improvement and a standard N-terminal pro-brain natriuretic peptide-based cardiac response survived longer than those achieving a biomarker-based cardiac response alone (P < 0.0001). CONCLUSION: Baseline LS% is a functional marker that correlates with worsening cardiac involvement and is predictive of survival. Baseline LS% and an absolute improvement in LS% are useful additional measures of prognosis and response to therapy in cardiac AL amyloidosis, respectively

Minimal residual disease negativity by next-generation flow cytometry is associated with improved organ response in AL amyloidosis

© The Author(s) 2021.Light chain (AL) amyloidosis is caused by a small B-cell clone producing light chains that form amyloid deposits and cause organ dysfunction. Chemotherapy aims at suppressing the production of the toxic light chain (LC) and restore organ function. However, even complete hematologic response (CR), defined as negative serum and urine immunofixation and normalized free LC ratio, does not always translate into organ response. Next-generation flow (NGF) cytometry is used to detect minimal residual disease (MRD) in multiple myeloma. We evaluated MRD by NGF in 92 AL amyloidosis patients in CR. Fifty-four percent had persistent MRD (median 0.03% abnormal plasma cells). There were no differences in baseline clinical variables in patients with or without detectable MRD. Undetectable MRD was associated with higher rates of renal (90% vs 62%, p = 0.006) and cardiac response (95% vs 75%, p = 0.023). Hematologic progression was more frequent in MRD positive (0 vs 25% at 1 year, p = 0.001). Altogether, NGF can detect MRD in approximately half the AL amyloidosis patients in CR, and persistent MRD can explain persistent organ dysfunction. Thus, this study supports testing MRD in CR patients, especially if not accompanied by organ response. In case MRD persists, further treatment could be considered, carefully balancing residual organ damage, patient frailty, and possible toxicity.This study was supported by a grant from CARIPLO “Molecular mechanisms of Ig toxicity in age-related plasma cell dyscrasias no. 2015-0591”, by a grant from the Black Swan Research Initiative from the International Myeloma Foundation “Automated multidimensional flow cytometry for high-sensitive screening and to monitor response in AL amyloidosis”, by a grant from CARIPLO “Structure–function relation of amyloid: understanding the molecular bases of protein misfolding diseases to design new treatments no. 2013-0964”, by a grant from the Amyloidosis Foundation “Investigating new therapies to treat AL amyloidosis”, and by a grant from Cancer Research UK, FCAECC and AIRC under the Accelerator Award 2017 Program “Early detection and intervention: understanding the mechanisms of transformation and hidden resistance of incurable hematological malignancies”, by a grant from CARIPLO “Harnessing the plasma cell secretory capacity against systemic light chain amyloidosis” (no. 2018-0257), by a grant from the Italian Ministry of Health “Towards effective, patient-tailored anti-plasma cell therapies in AL amyloidosis: predicting drug response and overcoming drug resistance” (GR-2018-12368387). This study has also supported the Centro de Investigación Biomédica en Red—Área de Oncología—del Instituto de Salud Carlos III (CIBERONC; CB16/12/00369, CB16/12/00400, and CB16/12/00489) and the Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS No. PI13/02196). G.P. is supported in part by the Bart Barlogie Young Investigator Award from the International Myeloma Society (IMS). P.M. is supported in part by a fellowship grant form Collegio Ghislieri (Pavia). We acknowledge the study coordinator and data manager Anna Carnevale Baraglia

Cardiac transplantation in transthyretin amyloid cardiomyopathy: Outcomes from three decades of tertiary center experience

Aims: Transthyretin cardiac amyloidosis (ATTR-CM) is a progressive and fatal cardiomyopathy. Treatment options in patients with advanced ATTR-CM are limited to cardiac transplantation (CT). Despite case series demonstrating comparable outcomes with CT between patients with ATTR-CM and non-amyloid cardiomyopathies, ATTR-CM is considered to be a contraindication to CT in some centers, partly due to a perceived risk of amyloid recurrence in the allograft. We report long-term outcomes of CT in ATTR-CM at two tertiary centers. Materials and methods and results: We retrospectively evaluated ATTR-CM patients across two tertiary centers who underwent transplantation between 1990 and 2020. Pre-transplantation characteristics were determined and outcomes were compared with a cohort of non-transplanted ATTR-CM patients. Fourteen (12 male, 2 female) patients with ATTR-CM underwent CT including 11 with wild-type ATTR-CM and 3 with variant ATTR-CM (ATTRv). Median age at CT was 62 years and median follow up post-CT was 66 months. One, three, and five-year survival was 100, 92, and 90%, respectively and the longest surviving patient was Censored > 19 years post CT. No patients had recurrence of amyloid in the cardiac allograft. Four patients died, including one with ATTRv-CM from complications of leptomeningeal amyloidosis. Survival among the cohort of patients who underwent CT was significantly prolonged compared to UK patients with ATTR-CM generally (p < 0.001) including those diagnosed under age 65 years (p = 0.008) or with early stage cardiomyopathy (p < 0.001). Conclusion: CT is well-tolerated, restores functional capacity and improves prognosis in ATTR-CM. The risk of amyloid recurrence in the cardiac allograft appears to be low

Commercial Immunoglobulin Products Contain Neutralizing Antibodies Against Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein

BACKGROUND: Patients with antibody deficiency respond poorly to COVID-19 vaccination and are at risk of severe or prolonged infection. They are given long-term immunoglobulin replacement therapy (IRT) prepared from healthy donor plasma to confer passive immunity against infection. Following widespread COVID-19 vaccination alongside natural exposure, we hypothesised that immunoglobulin preparations will now contain neutralising SARS-CoV-2 spike antibodies which confer protection against COVID-19 disease and may help to treat chronic infection. METHODS: We evaluated anti-SARS-CoV-2 spike antibody in a cohort of patients before and after immunoglobulin infusion. Neutralising capacity of patient samples and immunoglobulin products was assessed using in vitro pseudo-virus and live-virus neutralisation assays, the latter investigating multiple batches against current circulating omicron variants. We describe the clinical course of nine patients started on IRT during treatment of COVID-19. RESULTS: In 35 individuals with antibody deficiency established on IRT, median anti-spike antibody titre increased from 2123 to 10600 U/ml post-infusion, with corresponding increase in pseudo-virus neutralisation titres to levels comparable to healthy donors. Testing immunoglobulin products directly in the live-virus assay confirmed neutralisation, including of BQ1.1 and XBB variants, but with variation between immunoglobulin products and batches.Initiation of IRT alongside Remdesivir in patients with antibody deficiency and prolonged COVID-19 infection (median 189 days, maximum over 900 days with an ancestral viral strain) resulted in clearance of SARS-CoV-2 virus at a median of 20 days. CONCLUSIONS: Immunoglobulin preparations now contain neutralising anti-SARS-CoV-2 antibodies which are transmitted to patients and help to treat COVID-19 in individuals with failure of humoral immunity

Tc-99m labelled bone scintigraphy in suspected cardiac amyloidosis

AIMS: To perform evaluation of widely embraced bone scintigraphy-based non-biopsy diagnostic criteria (NBDC) for ATTR amyloid cardiomyopathy (ATTR-CM) in clinical practice, and to refine serum free light chain (sFLC) ratio cut-offs that reliably exclude monoclonal gammopathy (MG) in chronic kidney disease. METHODS AND RESULTS: A multi-national retrospective study of 3354 patients with suspected or histologically proven cardiac amyloidosis (CA) referred to specialist centres from 2015 to 2021; evaluations included radionuclide bone scintigraphy, serum and urine immunofixation, sFLC assay, eGFR measurement and echocardiography. Seventy-nine percent (1636/2080) of patients with Perugini grade 2 or 3 radionuclide scans fulfilled NBDC for ATTR-CM through absence of a serum or urine monoclonal protein on immunofixation together with a sFLC ratio falling within revised cut-offs incorporating eGFR; 403 of these patients had amyloid on biopsy, all of which were ATTR type, and their survival was comparable to non-biopsied ATTR-CM patients (p = 0.10). Grade 0 radionuclide scans were present in 1091 patients, of whom 284 (26%) had CA, confirmed as AL type (AL-CA) in 276 (97%) and as ATTR-CM in only one case with an extremely rare TTR variant. Among 183 patients with grade 1 radionuclide scans, 122 had MG of whom 106 (87%) had AL-CA; 60/61 (98%) without MG had ATTR-CM. CONCLUSION: The NBDC for ATTR-CM are highly specific [97% (95% CI 0.91-0.99)] in clinical setting, and diagnostic performance was further refined here using new cut-offs for sFLC ratio in patients with CKD. A grade 0 radionuclide scan all but excludes ATTR-CM but occurs in most patients with AL-CA. Grade 1 scans in patients with CA and no MG are strongly suggestive of early ATTR-type, but require urgent histologic corroboration

Expression and Function of NUMB in Ameloblast Differentiation

Objective. To determine whether NUMB plays roles in the differentiation of the dental cells. Background. NUMB has been implicated to play roles in lineage commitment by both gain- and loss-of function approaches. Its function has been attributed to the asymmetric distribution in daughter cells. Methods. RT-PCR, western blot, immunocytochemistry, confocal microscopy and PCR super-array analysis were applied to study the expression and signaling regulatory effects of NUMB. Results. We isolated 2 fulllength clones for NUMB from mouse dental pulp mRNA. One novel sequence contains 200bp insertion in the Phosphotyrosine Binding Domain (PTB) may encode for a new isoform of NUMB. Confocol microscopy detected strong NUMB expression in human dental pulp stem cells (hDPSC), odontoblasts (Od) and pre-ameloblasts (pre-Ab). Western blot analysis indicated NUMB isoforms were differentially expressed in dental tissues. In postnatal mouse tooth germs, NUMB was expressed in the preameloblasts and Odontoblasts, cervical loops, and DPSC in the vicinity of the immature odontoblasts. NUMB overexpression in pre-ameloblasts, significantly reduced activated Notch1 protein expression level. In the super array analysis of Notch1 signaling, NUMB down regulates Shh expression in preamelobasts. Conclusion. New NUMB mRNA was detected in dental pulp cells. NUMB has a temporal expression pattern in developing tooth germs suggesting critical role of NUMB in ameloblasts and odontoblasts differentiation. NUMB negatively regulate activated Notch 1 and SHH signaling in Hat-7 cells. Grants. This work was supported by NIH grant DE 11657 and the Department of Orthodontics at UIC