Immunoglobulin light chain amyloidosis: 2020 update on diagnosis, prognosis, and treatment

The American College of Cardology/American Heart Association Heart Failure Staging System Highlights Diagnostic Delay and Predicts Outcome in Transthyretin Cardiac Amyloidosis

OBJECTIVE

To apply the American College of Cardiology (ACC) and American Heart Association (AHA) heart failure (HF) staging system to patients with transthyretin cardiac amyloidosis (TTR-CA) in order to assess diagnostic delay and evaluate prognosis.

PATIENTS AND METHODS

Consecutive patients with TTR-CA enrolled in an Italian registry were classified according to the ACC/AHA HF staging system at diagnosis. Outcome was assessed as all-cause mortality during a 3-year follow-up.

RESULTS

At diagnosis, of 549 patients with TTR-CA, 115 (20.9%) presented with HF stage B, 172 (31.3%) with stage C1, 198 (36.1%) with stage C2, and 64 (11.7%) with stage D. Patients with stages B, C1, C2, and D presented with hierarchically higher prevalence of left ventricular systolic impairment, advanced diastolic dysfunction, advanced New York Heart Association functional class, hospitalization for HF, and N-terminal pro-B-type natriuretic peptide values. At 3 years, the survival rate was 94% in patients with stage B HF, decreasing to 69% with stage C1, 43% with stage C2, and 17% with stage D. At multivariable analysis, considering stage B as the reference, risk increase for all-cause mortality was 4, 5, and 11 for stages C1, C2, and D, respectively.

CONCLUSION

At diagnosis, almost half of patients with TTR-CA present with advanced stages of HF (C2 or D), suggesting marked diagnostic delay. The ACC/AHA HF staging system accurately stratifies prognosis and may be usefully added to the multiparametric evaluation of patients with TTR-CA.

Role of a Multidisciplinary Program (Amyloidosis Program of Calgary) on Recognition and Intervention for AL and ATTR Amyloidosis

BACKGROUND

The diagnosis and management of amyloidosis requires strong coordination among various teams and a multidisciplinary approach which is essential for providing the diagnostic tools needed for patients with organ amyloid deposition.

METHODS

In this study, we reviewed the referral patterns to the cardiac and hematology amyloid clinics since the inception of the Amyloidosis Program of Calgary (APC) in 2019. The APC was established to facilitate the diagnosis and treatment of amyloidosis. Additionally, a central referral system was created to expedite the triage of cases with potential amyloid-related symptoms.

RESULTS

The cardiac amyloid clinic saw an increase in referrals from 41 in 2018 to 105 in 2022, although there was a temporary decrease from 67 in 2019 to 56 in 2020 during the first year of the pandemic. Most referrals came from nonamyloid cardiology clinics, followed by hematology referrals. Fifty percent of the cases referred were patients with ATTR and 18% represented AL cases. Moreover, amyloid clinic at our cancer center also began receiving referrals via the central triage system in 2019, with AL amyloidosis cases increasing from 16 to 25 between 2018 and 2023. Therefore, we report here the significant impact of the APC on increasing referrals for patients with ATTR, with the program facilitating diagnostic pathways for these rare conditions.

IN SUMMARY

Since 2022, the establishment of an amyloid screening clinic has furthered these efforts, aiming to enhance early recognition and improve clinical outcomes.

Venetoclax Plus CyBorD Induction Therapy and Venetoclax Maintenance Treatment for Immunoglobulin Light Chain Amyloidosis with t(11;14) Translocation

Background: A total of 50% of patients with AL amyloidosis have t(11;14) translocation, allowing us to use the selective oral BCL-2 inhibitor venetoclax in their treatment. Case presentation: Our patient was admitted to the gastroenterology department due to weight loss and abdominal pain. An abdominal CT scan revealed some enlarged lymph nodes; therefore, he was referred to the hematology department. A bone marrow biopsy showed massive amorphous amyloid deposition. The sample was positive on Congo red staining and exhibited double refraction under a polarized light microscope. Serum-free light chains and the difference between involved and uninvolved free light chains (dFLCs) were elevated. Using fluorescent in situ hybridization, we detected t(11;14) translocation. Further examinations confirmed the involvement of the liver, colon and heart. Stage II AL amyloidosis was confirmed. Our patient received combined induction therapy with CyBorD and venetoclax due to the presence of the t(11;14) translocation. After six cycles, the patient achieved complete remission. Autologous stem cell transplantation (ASCT) was performed. At 100 days post-ASCT, the patient had complete hematologic remission. Venetoclax maintenance treatment was initiated. The follow-up examinations showed that the patient is in very good partial remission. Conclusions: In the case of our AL amyloidosis patient with t(11;14) translocation, the combined treatment with CyBorD and venetoclax was well tolerated and effective.

Optimizing multiple Myeloma clinical trials: research direction, addressing limitations, and strategies for improvement

Despite significant advancements in multiple myeloma (MM) treatment, including novel therapies and combination strategies, the translation of findings from randomized controlled trials (RCTs) into real-world clinical practice has been associated with several challenges. Specifically, the principles and criterion that shape the current design of MM RCTs have left out a sizable portion of patients that would particularly benefit from trial inclusion. In addition, RCTs may use primary outcomes which only partially cover patient-relevant endpoints important for evaluating treatment efficacy and quality of life. In this review, we explore the current MM RCT landscape and suggest possible solutions to improve generalizability of trial results, mitigate logistical pitfalls, and integrate real-world evidence into trials. Together, these strategies are designed to refine MM treatment guidelines and improve outcomes for all patient populations.

Case Report: Avoiding misdiagnosis in amyloidosis-navigating transthyretin genopositivity and monoclonal gammopathy in a patient with advanced heart failure and spinal stenosis

Background

A 63-year-old Black woman presented with progressive exertional dyspnea and chronic lower back pain. The course and findings in her case are instructive.

Case report

Family history was notable for cardiac deaths. An echocardiogram demonstrated ventricular wall thickening with diastolic dysfunction. The patient's N-terminal pro b-type natriuretic peptide level was 1,691 pg/ml with a troponin I level of 0.36 ng/ml. Transthyretin (TTR) sequencing detected a heterozygous V122I variant. The patient's free κ light chain level in serum was 664 mg/L with a ratio of 16.5. Bone marrow analysis showed 20%-30% κ-restricted plasma cells with amyloid deposits. A technetium-99m sodium pyrophosphate scan was performed and was negative. Magnetic resonance imaging of the total spine showed ligamentum flavum (LF) thickening at L4-5, causing severe spinal stenosis. In both the abdominal fat and the LF, liquid chromatography-coupled tandem mass spectrometry confirmed κ-type immunoglobulin light chain (AL) amyloidosis; the quantitative estimate of amyloid content in the LF was 5%. She was diagnosed with AL amyloidosis with Mayo Stage IIIA cardiac and soft tissue involvement, enrolled in the Aquarius trial (NCT05250973) in Cohort 2, and received daratumumab, cyclophosphamide, bortezomib, and dexamethasone. She achieved a partial hematological response with a cardiac response and is now pain-free and fully functional.

Conclusion

In patients with amyloidosis who have both monoclonal gammopathy and a TTR variant, it is imperative to discern the tissue type of the amyloid to deduce the correct diagnosis. ATTR and AL amyloidosis can both cause spinal stenosis with minimal degenerative changes. The LF tissue must be stained for amyloids and, if present, typing must be performed.

Prognostic factors in Chinese patients with immunoglobulin light chain amyloidosis: a scoping review and meta-analysis

OBJECTIVE

This scoping review and meta-analysis aimed to map the evidence regarding prognostic factors in Chinese patients with immunoglobulin light chain (AL) amyloidosis and to identify current research gaps.

METHODS

We searched EMBASE, PubMed, and CNKI databases from their inception to 15 September 2021. All studies investigated the association between any prognostic factor and target outcomes, including overall survival (OS), progression-free survival (PFS), and end-stage renal disease (ESRD) in Chinese patients with AL amyloidosis.

RESULTS

This scoping review included 52 studies, of which 44 with 6,432 patients contributed to the multivariate prognostic analysis. Multivariate analysis identified a total of 106 factors that correlated with OS, 16 factors with PFS, and 18 factors with ESRD. Five prognostic factors were significantly associated with PFS, and 11 prognostic factors were significantly associated with ESRD. Meta-analysis was only available for prognostic factors without heterogeneous cutoff values, for which hazard ratios (HRs) and their 95% confidence intervals (CIs) were reported. Meta-analysis showed that bone marrow plasma cells (BMCs) (HR: 1.96, 95% CI: 1.21-3.19, p < 0.05) and interventricular septal thickness (IVST) (HR: 1.23, 95% CI: 1.10-1.38, p < 0.05) were independently associated with OS.

CONCLUSION

The significant prognostic factors associated with OS, PFS, and ESRD in Chinese patients with AL amyloidosis were related to plasma cell tumor load, biological characteristics, cardiac involvement, renal involvement, population characteristics, and treatment. Further studies should explore additional prognostic factors in patients with AL amyloidosis to develop prognostic models.

Influence mechanism of serum free immunoglobulin light chain on pulmonary inflammatory response and serum levels of inflammatory factors in patients with chronic obstructive pulmonary disease

Background

The pathogenesis of chronic obstructive pulmonary disease (COPD) is not fully understood. This work aimed to demonstrate the role of serum free light chains (sFLC) in the pulmonary inflammatory response of COPD patients and its relationship with serum inflammatory cytokine (IC) levels.

Methods

Eighty subjects were enrolled, including 40 COPD patients (COPD group) and 40 healthy controls (control group). All patients were further rolled into four subgroups regarding the Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging criteria. The serum levels of sFLC and ICs were compared between the two groups, and their correlations with lung function indicators were analyzed.

Results

The serum sFLC levels of COPD patients were markedly superior to those of healthy controls. The levels of serum sFLC and ICs (tumour necrosis factor-a (TNF-a), interleukin (IL)-6, IL-8) gradually increased with the severity of the disease. The levels of ICs were negatively correlated with lung function indicators (FEV1% predicted, FEV1/FVC).

Conclusions

These findings suggest that serum sFLC may play a critical role in the pulmonary inflammatory response of COPD patients and serve as a potential indicator for evaluating COPD severity and predicting disease progression.

Impact of the Noninvasive Diagnostic Algorithm on Clinical Presentation and Prognosis in Cardiac Amyloidosis

Background

The introduction of a noninvasive diagnostic algorithm in 2016 led to increased awareness and recognition of cardiac amyloidosis (CA).

Objectives

The purpose of this study was to analyze the impact of the introduction of the noninvasive diagnostic algorithm on diagnosis and prognosis in a multicenter Italian CA cohort.

Methods

This was a retrospective analysis of 887 CA patients from 5 Italian Cardiomyopathies Referral Centers: 311 light-chain CA, 87 variant transthyretin (TTR)-related CA, 489 wild-type TTR-related CA. Clinical characteristics and outcomes (all-cause mortality and heart failure [HF] hospitalizations) were compared overall and for each CA subtype between patients diagnosed before versus after 2016. Outcomes were further compared by propensity score weighted Kaplan-Meier analysis and Cox regression analysis.

Results

CA diagnoses increased after 2016, in particular for wild-type TTR-related CA. Patients diagnosed after versus before 2016 were older, had less frequently a history of HF prior to diagnosis, and NYHA functional class III-IV at diagnosis. Over a median follow-up of 18 months, 172 (86%) patients diagnosed before 2016 died or had an HF hospitalization, versus 300 (44%) diagnosed after 2016. Propensity score weighted Kaplan-Meier analysis showed worse outcomes (P < 0.001) for patients diagnosed before 2016. At Cox regression analysis, CA diagnosis after 2016 was an independent protective factor for the composite outcome (HR: 0.69; P = 0.001), with interaction by CA subtype (significant in TTR-related CA and null in light-chain).

Conclusions

CA patients diagnosed after 2016 showed a less severe phenotype and a better prognosis. The impact of the noninvasive diagnostic algorithm on outcomes was particularly relevant in TTR-related CA.

Amyloid Neuropathy: From Pathophysiology to Treatment in Light-Chain Amyloidosis and Hereditary Transthyretin Amyloidosis

Amyloid neuropathy is caused by deposition of insoluble β-pleated amyloid sheets in the peripheral nervous system. It is most common in: (1) light-chain amyloidosis, a clonal non-proliferative plasma cell disorder in which fragments of immunoglobulin, light or heavy chain, deposit in tissues, and (2) hereditary transthyretin (ATTRv) amyloidosis, a disorder caused by autosomal dominant mutations in the TTR gene resulting in mutated protein that has a higher tendency to misfold. Amyloid fibrils deposit in the endoneurium of peripheral nerves, often extensive in the dorsal root ganglia and sympathetic ganglia, leading to atrophy of Schwann cells in proximity to amyloid fibrils and blood-nerve barrier disruption. Clinically, amyloid neuropathy is manifested as a length-dependent sensory predominant neuropathy associated with generalized autonomic failure. Small unmyelinated nerves are involved early and prominently in early-onset Val30Met ATTRv, whereas other ATTRv and light-chain amyloidosis often present with large- and small-fiber involvement. Nerve conduction studies, quantitative sudomotor axon testing, and intraepidermal nerve fiber density are useful tools to evaluate denervation. Amyloid deposition can be demonstrated by tissue biopsy of the affected organ or surrogate site, as well as bone-avid radiotracer cardiac imaging. Treatment of light-chain amyloidosis has been revolutionized by monoclonal antibodies and stem cell transplantation with improved 5-year survival up to 77%. Novel gene therapy and transthyretin stabilizers have revolutionized treatment of ATTRv, improving the course of neuropathy (less change in the modified Neuropathy Impairment Score + 7 from baseline) and quality of life. With great progress in amyloidosis therapies, early diagnosis and presymptomatic testing for ATTRv family members has become paramount. ANN NEUROL 2024;96:423-440.

Serum alpha 1 antitrypsin potent act as an early diagnostic biomarker for cardiac amyloidosis

Cardiac amyloidosis is a refractory cardiomyopathy with a poor prognosis and lacks effective treatments. N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin T are poor prognostic factors for myocardial amyloidosis. However, NT-proBNP and troponin also serve as markers of heart failure and myocardial infarction, lacking specificity. Whether abnormal elevation of alpha-1 antitrypsin in myocardial amyloidosis also predicts the poor prognosis of patients remains unknown. We conducted a retrospective single-center case-control study to analyze the serological and physical examination data of 83 cardiac amyloidosis patients and 68 healthy controls matched by gender and age. We aimed to explore the onset and prognostic factors of cardiac amyloidosis. The serum alpha-1 antitrypsin level (169.78 ± 39.59 mg/dl) in patients with cardiac amyloidosis was significantly higher than that in the normal control (125.92 ± 18.26 mg/dl). Logistic regression results showed that alpha-1 antitrypsin, free sialic acid, high-density lipoprotein cholesterol, apolipoprotein A/B ratio, and homocysteine were predictors of cardiac amyloidosis. Multivariable logistic regression showed that only alpha 1 antitrypsin was an independent risk factor for cardiac amyloidosis. Receiver operating characteristic curve analysis based on the Mayo stage and troponin level showed the cut-off value of 140.55 mg/dl for alpha-1 antitrypsin in predicting cardiac amyloidosis with 81.7% sensitivity and 83.9% specificity. Elevated alpha-1 antitrypsin levels may be an early diagnostic biomarker for cardiac amyloidosis.

Hepatic amyloidosis in a patient with chronic liver failure: A case report

BACKGROUND

Amyloidosis is a rare disorder that can be classified into various types, and the most common type is the systemic light chain type. The prognosis of this disease is extremely poor. In general, amyloidosis mainly affects the kidneys and heart and manifests as abnormal proliferation of clonal plasma cells. Cases in which the liver is the primary organ affected by amyloidosis, as in this report, are less common in clinical practice.

CASE SUMMARY

A 62-year-old man was admitted with persistent liver dysfunction of unknown cause and poor treatment outcomes. His condition persisted, and he developed chronic liver failure, with severe cholestasis in the later stage that was gradually accompanied by renal injury. Ultimately, he was diagnosed with hepatic amyloidosis through liver biopsy and pathological examination.

CONCLUSION

Hepatic amyloidosis rarely occurs in the clinic, and liver biopsy and pathological examination can assist in the accurate and effective diagnosis of this condition.

Urine immunofixation electrophoresis and serum free light chain analyses benefit diagnosis of multiple myeloma in orthopedic patients with normal serum total proteins, creatinine, calcium, and hemoglobin

BACKGROUND

A substantial number of patients with multiple myeloma (MM) who have bone destruction are initially admitted into the orthopedic service at the hospital. However, routine laboratory testing usually fails to identify these patients, thus delaying optimal therapy. Therefore, there is a clear medical need for early diagnosis of MM in these patients.

METHODS

Between 2019 and 2021, 42 patients receiving treatment for orthopedic conditions had normal hemoglobin (Hb), total protein (TP), albumin (ALB), creatinine (CREA), and blood calcium (Ca) levels before their surgical procedure(s) but were subsequently pathologically confirmed to have MM, based on their presenting orthopedic symptoms. During the same period, 52 patients with orthopedic conditions were pathologically excluded from the diagnosis of MM and were recruited into our control group. Serum free light chain (sFLC) testing was performed in 94 consecutive patients in the orthopedic service using Siemens N Latex FLC kits. The levels of Hb, TP, ALB, CREA, and Ca were also measured. All 42 patients with MM were divided into group A (n = 25: κ proliferation) and group B (n = 17: λ proliferation) by the pathology department.

RESULTS

There were no significant differences in levels of Hb, TP, ALB, CREA, and Ca between group A and group B and the control group. However, the sFLC κ/λ ratio of group A and B was also significantly different from that of the control group (P < .001). The results of serum immunofixation electrophoresis (IFE) testing demonstrated negative results in 14 cases (58.3%) in group A and 4 cases (25.0%) in group B.

CONCLUSIONS

Some patients with orthopedic conditions who do not have typical MM laboratory results, such as those with abnormal Hb, TP, ALB, CREA, and Ca levels before their operation(s), actually have MM. MM should be highly suspected in patients with unexplained bone lesions and with an abnormal sFLC κ/λ ratio. Further tissue or bone marrow biopsy is needed in these patients even if serum and urine IFE results are negative and light chain ratio is normal.

Paraprotein-Mediated Glomerular Diseases

Paraproteinemias are a group of complex diseases associated with an overproduction of a monoclonal immunoglobulin that can cause a diversity of kidney disorders and end-organ damage. In this review, we focus on paraprotein-mediated glomerular diseases. Kidney biopsy plays a crucial role in diagnosing these disorders, enabling the identification of specific histological patterns. These lesions are categorized into organized (such as amyloidosis, immunotactoid glomerulopathy, fibrillary glomerulonephritis, cryoglobulinemic glomerulonephritis, and monoclonal crystalline glomerulopathies) and nonorganized deposits (such as monoclonal Ig deposition disease and proliferative glomerulonephritis with monoclonal Ig deposits) based on the characteristics of immunofluorescence findings and the ultrastructural appearance of deposits on electron microscopy. This review aims to provide an update, highlight, and discuss clinicopathological aspects such as definition, epidemiology, clinical manifestations, mechanisms of kidney injury, histological features, and diagnostic procedures.

Monoclonal gammopathy-associated peripheral neuropathies: Uncovering pearls and challenges

Monoclonal gammopathy-related peripheral neuropathies encompass a spectrum of clinical presentations in which the monoclonal protein directly damages the tissues, including the peripheral nervous system. Given the prevalence of both peripheral neuropathy and monoclonal gammopathy in the general population, these conditions may overlap in clinical practice, posing a challenge for clinicians in determining causality. Therefore, a comprehensive understanding of primary clinical syndromes and their neurophysiological patterns is of great importance for accurate differential diagnoses and effective treatment strategies. In this article, we examine the main forms of monoclonal gammopathies that affect the peripheral nerve. We explore the clinical and electrophysiological aspects and their correlation with each syndrome's corresponding monoclonal protein type. This knowledge is essential for healthcare professionals to diagnose better and manage patients presenting with monoclonal gammopathy-related peripheral nervous system involvement.

Light chain deposition disease presenting with gastrointestinal disorder as primary manifestation: report of two cases and literature review

Light chain deposition disease (LCDD) is an under-recognized condition characterized by deposition of abnormal monoclonal light chains in tissues, leading to organ dysfunction. LCDD involving the gastrointestinal tract is very uncommon, and its diagnosis is challenging. We herein report two cases of LCDD that manifested as inflammatory bowel disease-like symptoms and protein-losing gastroenteropathy. Both patients were women in their early 60s. Tissue biopsies from the gastrointestinal mucosa demonstrated extracellular deposits, which were negative by Congo red staining but positive for κ-light chain by immunohistochemistry. The recent literature on LCDD was reviewed. When patients unexpectedly show extracellular deposits in gastrointestinal biopsy specimens, evaluation of immunoglobulin chains is recommended for diagnosis of LCDD after systemic amyloidosis has been excluded.

Autologous Stem Cell Transplant in Hodgkin's and Non-Hodgkin's Lymphoma, Multiple Myeloma, and AL Amyloidosis

Human body cells are stem cell (SC) derivatives originating from bone marrow. Their special characteristics include their capacity to support the formation and self-repair of the cells. Cancer cells multiply uncontrollably and invade healthy tissues, making stem cell transplants a viable option for cancer patients undergoing high-dose chemotherapy (HDC). When chemotherapy is used at very high doses to eradicate all cancer cells from aggressive tumors, blood-forming cells and leukocytes are either completely or partially destroyed. Autologous stem cell transplantation (ASCT) is necessary for patients in those circumstances. The patients who undergo autologous transplants receive their own stem cells (SCs). The transplanted stem cells first come into contact with the bone marrow and then undergo engraftment, before differentiating into blood cells. ASCT is one of the most significant and innovative strategies for treating diseases. Here we focus on the treatment of Hodgkin's lymphoma, non-Hodgkin's lymphoma, multiple myeloma, and AL amyloidosis, using ASCT. This review provides a comprehensive picture of the effectiveness and the safety of ASCT as a therapeutic approach for these diseases, based on the currently available evidence.

Emerging therapeutic avenues in cardiac amyloidosis

Cardiac Amyloidosis (CA) is a toxic infiltrative cardiomyopathy occurred by the deposition of the amyloid fibres in the extracellular matrix of the myocardium. This results in severe clinical complications such as increased left ventricular wall thickness and interventricular stiffness, a decrease in left ventricular stroke volume and cardiac output, diastolic dysfunction, arrhythmia, etc. In a prolonged period, this condition progresses into heart failure. The amyloid fibres affecting the heart include immunoglobulin light chain (AL - amyloidosis) and transthyretin protein (ATTR - amyloidosis) misfolded amyloid fibres. ATTRwt has the highest prevalence of 155 to 191 cases per million while ATTRv has an estimated prevalence of 5.2 cases per million. The pathological findings and therapeutic approaches developed recently have aided in the treatment regimen of cardiac amyloidosis patients. In recent years, understanding the pathophysiology of amyloid fibres formation and mechanistic pathways triggered in both types of cardiac amyloidosis has led to the development of new therapeutic approaches and agents. This review focuses on the current status of emerging therapeutic agents in clinical trials. Earlier, melphalan and bortezomib in combination with alkylating agents and immunomodulatory drugs were used as a standard therapy for AL amyloidosis. Tafamidis, approved recently by FDA is used as a standard for ATTR amyloidosis. However, the emerging therapeutic agents under development for the treatment of AL and ATTR cardiac amyloidosis have shown a potent and rapid effect with a safety profile.

Proteomic methods for the study of porcine acute phase proteins - anything new to detect?

Acute phase proteins (APPs) reflect the health status of individuals and are important tools in diagnostics, as their altered levels are a sign of disturbed homeostasis. While, in most cases, quantitation of known serum APPs is routinely performed by immunoassays, proteomics is helpful in discovery of new biomarker candidates, especially in samples other than body fluids. Besides putting APP regulation into an overall context of differentially abundant proteins, this approach can detect further details or outright new features in protein structure or specific modifications, and help understand better their function. Thus, it can show up ways to make present diagnostic assays more sensitive and/or specific, or correlate regulations of disease-specific proteins. The APP repertoire is dependent on the species. The pig is both, an important farm animal and a model animal for human diseases, due to similarities in physiology. Besides reviewing existing literature, yet unpublished examples for two-dimensional electrophoresis in connection with pig APPs highlight some of the benefits of proteomics. Of further help would be the emerging targeted proteomics, offering the possibility to determine particular isoforms or proteoforms, without the need of specific antibodies, but this method is presently scarcely used in veterinary medicine.

Assessing the prognostic utility of hematologic response for overall survival in patients with newly diagnosed AL amyloidosis: results of a meta-analysis

OBJECTIVES

Amyloid light-chain (AL) amyloidosis is a rare disease characterized by amyloid fibril deposits made up of toxic light chains causing progressive organ dysfunction and death. Recent studies suggest that hematologic response may be an important prognostic indicator of overall survival (OS) in AL amyloidosis. The aim of this study was to evaluate the trial-level association between hematologic complete response (CR) or very good partial response or better (≥ VGPR) and OS in newly diagnosed patients.

METHODS

Studies were identified via systematic literature review. Pooled effect estimates were generated by a random-effects model.

RESULTS

Nine observational studies reporting hematologic CR or ≥VGPR and OS hazard ratios (HRs) were included in the meta-analysis. Achieving hematologic CR was associated with improved OS (HR, 0.21; 95% confidence interval [CI] 0.13-0.34). Achieving ≥ VGPR was also associated with improved OS (HR 0.21; 95% CI 0.17-0.26). Results of a sensitivity analysis excluding one outlier study revealed no heterogeneity and a better overall HR estimate. Potential limitations of this meta-analysis include the small number of eligible studies (consistent with the rarity of the disease) and inconsistencies in reporting of results.

CONCLUSIONS

Overall, our findings support the use of deep hematologic response (CR or ≥VGPR) as a clinical trial endpoint in newly diagnosed AL amyloidosis. This study provides evidence that early hematologic response is a strong patient-level surrogate for long-term OS in patients with AL amyloidosis receiving frontline therapy. Structured data collection of depth of response in future trials will further strengthen these observations.

Association Between Hematologic Response and Change in Health-Related Quality of Life Among Patients with Light-Chain (AL) Amyloidosis

Purpose

The purpose of this secondary data analysis was to examine the association between hematologic response and health-related quality of life (HRQoL) among patients with light-chain (AL) amyloidosis.

Patients and Methods

Data for this secondary analysis were collected through a non-interventional, longitudinal, online self-report survey of patients with AL amyloidosis. Patients completed an initial online survey, with follow-up surveys administered 1, 6, 12, 18, and 24 months after completion of the initial survey. The online survey included an assessment of patients' most recent self-reported hematologic response status. Eight domains and 2 summary components of HRQoL were evaluated with the SF-36v2® Health Survey. A series of logistic regression models were used to examine the association between self-reported hematologic response at 24 months (dichotomized as new or maintained complete hematologic response; less than a complete response) and change in HRQoL from baseline to 24 months (dichotomized as meaningful worsening; improvement or preservation).

Results

For all measured domains of HRQoL except physical functioning, there was no statistically significant relationship between meaningful worsening in HRQoL and hematologic response status at 24 months. Patients without a complete hematologic response had an odds of experiencing meaningful worsening of HRQoL that was similar to that of patients with a complete hematologic response.

Conclusion

Among patients with AL amyloidosis, change in HRQoL was generally not associated with hematologic response. Achieving a complete hematologic response does not necessarily mean that a patient will experience increased or stable HRQoL. When defining treatment success, it is important to recognize that clinical markers such as hematologic response may not fully encapsulate the patient experience.

Natriuretic Peptides and Cardiac Troponins: Markers of Disease Progression and Risk in Light Chain Cardiac Amyloidosis

PURPOSE OF REVIEW

Light chain (AL) amyloidosis can cause an infiltrative cardiomyopathy that can result in symptomatic heart failure. The vague, nonspecific onset of signs and symptoms may lead to a delay in diagnosis and treatment leading to poor outcomes. Cardiac biomarkers, such as troponins and natriuretic peptides, play a pivotal role in diagnosis, determining prognosis, and assessing treatment response in patients with AL amyloidosis. Because of the evolving landscape for both diagnosis and treatment of AL cardiac amyloidosis, we review the critical role these and other biomarkers play in the clinical management of this disease.

RECENT FINDINGS

A number of conventional cardiac and noncardiac serum biomarkers are commonly used in AL cardiac amyloidosis and may be surrogates for cardiac involvement and inform prognosis. These include typical heart failure biomarkers such as levels of circulating natriuretic peptides as well as cardiac troponins. Other noncardiac biomarkers frequently measured in AL cardiac amyloidosis included difference between the involved and uninvolved free light chains (dFLC) and markers of endothelial cell activation and damage such as von Willebrand factor antigen and matrix metalloproteinases. AL amyloidosis can lead to cardiac involvement which has been associated with poor outcomes, especially if not identified and treated early. Natriuretic peptides and cardiac troponins are cornerstones for the diagnosis and management of AL cardiac amyloidosis. Their levels may represent cardiac stress, injury, and possibly degree of cardiac involvement, and they play a key role in AL amyloidosis disease staging.

Using a Modified Delphi Panel to Estimate Health Service Utilization for Patients with Advanced and Non-Advanced Systemic Light Chain Amyloidosis

Purpose

Patients with diagnosed with systemic light chain (AL) amyloidosis at advanced Mayo stages have greater morbidity and mortality than those diagnosed at non-advanced stages. Estimating service use by severity is difficult because Mayo stage is not available in many secondary databases. We used an expert panel to estimate healthcare utilization among advanced and non-advanced AL amyloidosis patients.

Patients and Methods

Using the RAND/UCLA modified Delphi method, expert panelists completed 180 healthcare utilization estimates, consisting of inpatient and outpatient visits, testing, chemotherapy, and procedures by disease severity and organ involvement during two treatment phases (the 1 year after starting first line [1L] therapy and 1 year following treatment [post-1L]). Estimates were also provided for post-1L by hematologic treatment response (complete or very good partial response [CR/VGPR], partial, no response or relapse [PR/NR/R]). Areas of disagreement were discussed during a meeting, after which ratings were completed a second time.

Results

During 1L therapy, 55% of advanced patients had ≥1 hospitalization and 38% had ≥2 admissions. Rates of hematopoietic stem cell transplant (HSCT) in advanced patients were 5%, while pacemaker or implantable cardioverter defibrillator (ICD) placement were 15%. During post-1L therapy, rates of hospitalization in advanced patients remained high (≥1 hospitalization: 20-43%, ≥2 hospitalizations: 10-20%), and up to 10% of advanced patients had a HSCT. Ten percent of these patients underwent pacemaker/ICD placement.

Conclusion

Experts estimated advanced patients, who would not be good candidates for HSCT, would have high rates of hospitalization (traditionally the most expensive type of healthcare utilization) and other health service use. The development of new treatment options that can facilitate organ recovery and improve function may lead to decreased utilization.

Unveiling the Effects of Copper Ions in the Aggregation of Amyloidogenic Proteins

Amyloid diseases have become a global concern due to their increasing prevalence. Transition metals, including copper, can affect the aggregation of the pathological proteins involved in these diseases. Copper ions play vital roles in organisms, but the disruption of their homeostasis can negatively impact neuronal function and contribute to amyloid diseases with toxic protein aggregates, oxidative stress, mitochondrial dysfunction, impaired cellular signaling, inflammation, and cell death. Gaining insight into the imbalance of copper ions and its impact on protein folding and aggregation is crucial for developing focused therapies. This review examines the influence of copper ions on significant amyloid proteins/peptides, offering a comprehensive overview of the current understanding in this field.

Membranous nephropathy with systemic light-chain amyloidosis of remission after rituximab therapy: A case report

BACKGROUND

About 70%-80% of patients with primary membranous nephropathy (MN) have phospholipase A2 receptor (PLA2R) in renal tissue. Systemic light-chain (AL) amyloidosis is the most common type of amyloidosis. MN complicated with amyloidosis is rare.

CASE SUMMARY

A 48-year-old Chinese male presented with nephrotic syndrome, positive serum PLA2R antibody, and positive serum and urine IgG-lambda type M-protein, with a normal ratio of serum-free light-chain level. The patient was diagnosed with MN accompanied by AL amyloidosis. He was treated with rituximab with glucocorticoids and CyBorD regimen of chemotherapy. After 21 mo of follow-up, the patient achieved complete remission regarding nephrotic syndrome without adverse effects of chemotherapy.

CONCLUSION

We report a case of PLA2R-related MN complicated with primary AL amyloidosis only with renal involvement and successfully treated with rituximab, glucocorticoids and chemotherapy.

A Complex Case of Extensive Systemic Amyloidosis With Underlying Monoclonal Gammopathy

Systemic amyloid light chain, or primary amyloidosis (AL amyloidosis), is a serious medical condition that leads to the deposition of abnormal proteins called amyloid fibrils in various organs of the body. AL amyloidosis can present with different symptoms, which can make diagnosis challenging. This case report presents a clinical scenario of a 53-year-old female patient who had come in for shortness of breath and lower extremity swelling and was found to have acute on chronic pulmonary embolism. The patient had a history of systemic amyloidosis diagnosed with a kidney and duodenal biopsy. She also had a bone marrow biopsy done and was found to have IgG monoclonal gammopathy. Throughout the hospital course, patients required cautious diuretic use given the worsening kidney function. She was given intravenous anticoagulation initially and later switched to oral medication on discharge. Due to the aggressive nature of amyloidosis, a decision was made to start the patient on chemotherapy in an outpatient setting. This case presents an interesting scenario of systemic amyloidosis with concomitant monoclonal gammopathy that was complicated by acute pulmonary embolism. The case is important as it shows the different levels of amyloidosis and teaches us the benefit of taking a multidisciplinary approach to making a concrete plan for patients with advanced amyloidosis disease.

A man in his seventies with fatigue and renal failure

A man in his seventies underwent routine heart examinations as part of workup for kidney transplantation. Unexpected findings led to more extensive investigations and revealed two rare systemic diseases as causes of his heart failure.

A review: Exploring the metabolic and structural characterisation of beta pleated amyloid fibril in human tissue using Raman spectrometry and SAXS

Amyloidosis is a deleterious condition caused by abnormal amyloid fibril build-up in living tissues. To date, 42 proteins that are linked to amyloid fibrils have been discovered. Amyloid fibril structure variation can affect the severity, progression rate, or clinical symptoms of amyloidosis. Since amyloid fibril build-up is the primary pathological basis for various neurodegenerative illnesses, characterization of these deadly proteins, particularly utilising optical techniques have been a focus. Spectroscopy techniques provide significant non-invasive platforms for the investigation of the structure and conformation of amyloid fibrils, offering a wide spectrum of analyses ranging from nanometric to micrometric size scales. Even though this area of study has been intensively explored, there still remain aspects of amyloid fibrillization that are not fully known, a matter hindering progress in treating and curing amyloidosis. This review aims to provide recent updates and comprehensive information on optical techniques for metabolic and proteomic characterization of β-pleated amyloid fibrils found in human tissue with thorough literature analysis of publications. Raman spectroscopy and SAXS are well established experimental methods for study of structural properties of biomaterials. With suitable models, they offer extended information for valid proteomic analysis under physiologically relevant conditions. This review points to evidence that despite limitations, these techniques are able to provide for the necessary output and proteomics indication in order to extrapolate the aetiology of amyloid fibrils for reliable diagnostic purposes. Our metabolic database may also contribute to elucidating the nature and function of the amyloid proteome in development and clearance of amyloid diseases.

The flutemetamol analogue cyano-flutemetamol detects myocardial AL and ATTR amyloid deposits: a post-mortem histofluorescence analysis

BACKGROUND

[18F]flutemetamol is a PET radioligand used to image brain amyloid, but its detection of myocardial amyloid is not well-characterized. This histological study characterized binding of fluorescently labeled flutemetamol (cyano-flutemetamol) to amyloid deposits in myocardium.

METHODS

Myocardial tissue was obtained post-mortem from 29 subjects with cardiac amyloidosis including transthyretin wild-type (ATTRwt), hereditary/variant transthyretin (ATTRv) and immunoglobulin light-chain (AL) types, and from 10 cardiac amyloid-free controls. Most subjects had antemortem electrocardiography, echocardiography, SPECT and cardiac MRI. Cyano-flutemetamol labeling patterns and integrated density values were evaluated relative to fluorescent derivatives of Congo red (X-34) and Pittsburgh compound-B (cyano-PiB).

RESULTS

Cyano-flutemetamol labeling was not detectable in control subjects. In subjects with cardiac amyloidosis, cyano-flutemetamol labeling matched X-34- and cyano-PiB-labeled, and transthyretin- or lambda light chain-immunoreactive, amyloid deposits and was prevented by formic acid pre-treatment of myocardial sections. Cyano-flutemetamol mean fluorescence intensity, when adjusted for X-34 signal, was higher in the ATTRwt than the AL group. Cyano-flutemetamol integrated density correlated strongly with echocardiography measures of ventricular septal thickness and posterior wall thickness, and with heart mass.

CONCLUSION

The high selectivity of cyano-flutemetamol binding to myocardial amyloid supports the diagnostic utility of [18F]flutemetamol PET imaging in patients with ATTR and AL types of cardiac amyloidosis.

Free Light Chains κ and λ as New Biomarkers of Selected Diseases

Diagnostic and prognostic markers are necessary to help in patient diagnosis and the prediction of future clinical events or disease progression. As promising biomarkers of selected diseases, the free light chains (FLCs) κ and λ were considered. Measurements of FLCs are currently used in routine diagnostics of, for example, multiple myeloma, and the usefulness of FLCs as biomarkers of monoclonal gammopathies is well understood. Therefore, this review focuses on the studies concerning FLCs as new potential biomarkers of other disorders in which an inflammatory background has been observed. We performed a bibliometric review of studies indexed in MEDLINE to assess the clinical significance of FLCs. Altered levels of FLCs were observed both in diseases strongly connected with inflammation such as viral infections, tick-borne diseases or rheumatic disorders, and disorders that are moderately associated with immune system reactions, e.g., multiple sclerosis, diabetes, cardiovascular disorders and cancers. Increased concentrations of FLCs appear to be a useful prognostic marker in patients with multiple sclerosis or tick-borne encephalitis. Intensive synthesis of FLCs may also reflect the production of specific antibodies against pathogens such as SARS-CoV-2. Moreover, abnormal FLC concentrations might predict the development of diabetic kidney disease in patients with type 2 diabetes. Markedly elevated levels are also associated with increased risk of hospitalization and death in patients with cardiovascular disorders. Additionally, FLCs have been found to be increased in rheumatic diseases and have been related to disease activity. Furthermore, it has been suggested that inhibition of FLCs would reduce the progression of tumorigenesis in breast cancer or colitis-associated colon carcinogenesis. In conclusion, abnormal levels of κ and λ FLCs, as well as the ratio of κ:λ, are usually the result of disturbances in the synthesis of immunoglobulins as an effect of overactive inflammatory reactions. Therefore, it seems that κ and λ FLCs may be significant diagnostic and prognostic biomarkers of selected diseases. Moreover, the inhibition of FLCs appears to be a promising therapeutical target for the treatment of various disorders where inflammation plays an important role in the development or progression of the disease.

Systemic AL amyloidosis: current approach and future direction

Systemic Light chain (AL) amyloidosis is a monoclonal plasma cell proliferative disorder characterized by deposition of amyloidogenic monoclonal light chain fragments causing organ dysfunction. It is a fatal disease and if not diagnosed and treated early can lead to organ failure and potentially death. The renal system along with the cardiovascular system are the most common organs involved but other organs such as gut and liver can be involved as well. The initial evaluation of patients requires confirming the diagnosis with tissue biopsy and staining with Congo red followed by confirmatory typing with mass spectrometry of the Congo red positive tissue. Then establishing the extent of the organs involvement by various staging and biomarkers testing. The treatment options and the tolerability of therapy depend on the disease staging, frailty, and co-morbidities. The autologous hematopoietic cell transplantation (HCT) after high dose melphalan therapy is an effective strategy which is usually done after initial bortezomib induction therapy. Unfortunately, most systemic AL amyloidosis patients are not candidate for HCT due to frailty, old age, multi-organ involvement, renal and heart failure at the time of diagnosis. While it is widely accepted that the patients need to be treated until they achieve complete hematologic response, the maintenance therapy after HCT is not well established in AL amyloidosis. In this review, we report the literature on the latest treatment updates of AL amyloidosis and the ongoing clinical trials highlighting the future treatments.

A Nomogram Model for Predicting the Postoperative Recurrence of Localized Laryngeal Amyloidosis

OBJECTIVE

To analyze the factors related to postoperative recurrence in patients with localized laryngeal amyloidosis (LocLA) and to construct a nomogram prediction model (NPM).

METHODS

We collected the data for LocLA patients diagnosed from March 2000 to May 2019 and clinical characteristics data were extracted. Factors related to recurrence were analyzed using multivariate logistic regression. The NPM was constructed for predicting the recurrence risk of LocLA. The receiver operating characteristic (ROC) curve evaluated the distinguishing ability using the area under curve (AUC). The calibration curve was created to evaluate the consistency of the NPM.

RESULTS

A total of 226 confirmed LocLA cases were included. One hundred seventy-five cases (77.4%) had localized single nodule, and 51 cases had more than one lesions. Sixty-three (27.9%) cases had no multinucleated giant cell (MGC) around amyloid, and 163 (72.1%) cases had MGC around amyloid. Multivariate logistic regression analysis showed that more than one lesions (odds ratio [OR] = 3.206 and 95% confidence interval [CI]: 1.492-6.888; P value: .003), subglottic involvement (OR = 2.926 and 95% CI: 1.300-6.585; P = .010), and no multinucleated giant cell (MGC) around amyloid (OR = 2.503 and 95% CI: 1.173-5.342; P = .018) had a statistically significant effect on postoperative LocLA recurrence (P < .05). The AUC of the ROC curve was 0.753 (95% CI: 0.667-0.832). The bias-corrected curve approached the ideal curve, with an average absolute error of 0.037.

CONCLUSIONS

More than one lesions, subglottic involvement, and no MGC around amyloid are risk factors for postoperative recurrence of LocLA. The NPM constructed has good applicability.

A Comprehensive Multidisciplinary Diagnostic Algorithm for the Early and Efficient Detection of Amyloidosis

Amyloidosis is a rare protein misfolding disease caused by the accumulation of amyloid fibrils in various tissues and organs. There are different subtypes of amyloidosis, with light chain (AL) amyloidosis being the most common. Amyloidosis is notoriously difficult to diagnose because it is clinically heterogeneous, no single test is diagnostic for the disease, and diagnosis typically involves multiple specialists. Here, we propose an integrated, multidisciplinary algorithm for efficiently diagnosing amyloidosis. Drawing on research from several medical disciplines, we have combined clinical decisions and best practices into a comprehensive algorithm to facilitate the early detection of amyloidosis. Currently, many patients are diagnosed more than 6 months after symptom onset, yet early diagnosis is the major predictor of survival. Our algorithm aims to shorten the time to diagnosis with efficient sequencing of tests and minimizing uninformative investigations. We also recommend typing and staging of confirmed amyloidosis to guide treatment. By reducing time to diagnosis, our algorithm could lead to earlier and more targeted treatment, ultimately improving prognosis and survival.

Antibodies gone bad - the molecular mechanism of light chain amyloidosis

Light chain amyloidosis (AL) is a systemic disease in which abnormally proliferating plasma cells secrete large amounts of mutated antibody light chains (LCs) that eventually form fibrils. The fibrils are deposited in various organs, most often in the heart and kidney, and impair their function. The prognosis for patients diagnosed with AL is generally poor. The disease is set apart from other amyloidoses by the huge number of patient-specific mutations in the disease-causing and fibril-forming protein. The molecular mechanisms that drive the aggregation of mutated LCs into fibrils have been enigmatic, which hindered the development of efficient diagnostics and therapies. In this review, we summarize our current knowledge on AL amyloidosis and discuss open issues.

In-hospital mortality in amyloid light chain amyloidosis: analysis of the Premier Healthcare Database

Aim: Describe the clinical and economic burden of hospitalizations for amyloid light chain (AL) amyloidosis. Materials & methods: This retrospective analysis used nationally representative hospital discharge data (2017-2020) to report discharge status, resource use and costs for hospitalizations among patients with AL amyloidosis. Results: Of 1341 patients identified, 92% were discharged alive and 8% experienced in-hospital death. Compared with the average US hospital stay during 2017-2019 (4.7 days, mean costs of $13,046 and mean charges of $54,496), hospital stays for AL amyloidosis were longer and costlier (9.7 days, $27,098.61, $111,233.91), especially in patients with in-hospital death (12.2 days, $44,966, $182,338.18). Conclusion: AL amyloidosis is associated with significant clinical and economic burden.

Single Center Experience of Autologous Stem Cell Transplantation in Patients with Systemic Light Chain Amyloidosis in Korea

BACKGROUND

Systemic light chains is the most common systemic amyloidosis. In patients with AL amyloidosis, the prognosis is influenced by the extent of organ damage, especially cardiac involvement. Autologous stem cell transplantation (ASCT) is a highly effective treatment for AL amyloidosis for selective patient METHODS: One hundred patients treated with ASCT for AL amyloidosis were reviewed in the Samsung Medical Center amyloidosis cohort. The cardiac, renal, and hematologic response was analyzed, and survival results compared based on organ involvement and hematologic response.

RESULTS

The most common involved organ was kidney (n = 62) followed by heart (n = 50). The organ response rate was 44.0% and 37.1% in the patients with cardiac and renal involvement, respectively. In hematologic response, overall response rate (ORR) was 79.0%, including 48.0% complete response (CR). Median overall survival (OS) in patients with and without hematologic CR were not reached and 64.2 months (95% CI, 19.5 to 109.0), respectively (P < .001). The survival rate was not significantly different between patients with or without cardiac or renal involvement. Treatment-related mortality (TRM) in 30 days and 100 days was 2.0% and 3.0%, respectively.

CONCLUSIONS

ASCT is an effective treatment option for eligible patients with AL amyloidosis. Achieving hematologic CR is essential for long-term survival.

The prognostic value of multiparametric cardiac magnetic resonance in patients with systemic light chain amyloidosis

Background

Late gadolinium enhancement (LGE) is a classic imaging modality derived from cardiac magnetic resonance (CMR), which is commonly used to describe cardiac tissue characterization. T1 mapping with extracellular volume (ECV) and native T1 are novel quantitative parameters. The prognostic value of multiparametric CMR in patients with light chain (AL) amyloidosis remains to be thoroughly investigated.

Methods

A total of 89 subjects with AL amyloidosis were enrolled from April 2016 to January 2021, and all of them underwent CMR on a 3.0 T scanner. The clinical outcome and therapeutic effect were observed. Cox regression was used to investigate the effect of multiple CMR parameters on outcomes in this population.

Results

LGE extent, native T1 and ECV correlated well with cardiac biomarkers. During a median follow-up of 40 months, 21 patients died. ECV (hazard ratio [HR]: 2.087 for per 10% increase, 95% confidence interval [CI]: 1.379-3.157, P < 0.001) and native T1 (HR: 2.443 for per 100 ms increase, 95% CI: 1.381-4.321, P=0.002) were independently predictive of mortality. A novel prognostic staging system based on median native T1 (1344 ms) and ECV (40%) was similar to Mayo 2004 Stage, and the 5-year estimated overall survival rates in Stage I, II, and III were 95%, 80%, and 53%, respectively. In patients with ECV > 40%, receiving autologous stem cell transplantation had higher cardiac and renal response rates than conventional chemotherapy.

Conclusion

Both native T1 and ECV independently predict mortality in patients with AL amyloidosis. Receiving autologous stem cell transplantation is effective and significantly improves the clinical outcomes in patients with ECV > 40%.

Amyloidoses in Onco-Nephrology Practice: A Multidisciplinary Case-Based Conference Report

Introduction and Objective

Amyloidoses are a heterogeneous group of disorders resulting from deposition of amyloid fibrils into extracellular tissues. While the kidneys are one of the most frequent sites of amyloid deposition, amyloid deposits can also affect a wide range of organ systems, including the heart, liver, gastrointestinal tract, and peripheral nerves. The prognosis of amyloidosis, especially with cardiac involvement, remains poor; however, a collaborative approach applying new tools for diagnosis and management may improve outcomes. In September 2021, the Canadian Onco-Nephrology Interest Group hosted a symposium to discuss diagnostic challenges and recent advances in the management of amyloidosis from the perspectives of the nephrologist, cardiologist, and onco-hematologist.

Methods and Sources of Information

Through structured presentations, the group discussed a series of cases highlighting the varied clinical presentations of amyloidoses affecting the kidney and heart. Expert opinions, clinical trial findings, and publication summaries were used to illustrate patient-related and treatment-related considerations in the diagnosis and management of amyloidoses.

Key findings

(1) Overview of the clinical presentation of amyloidoses and the role of specialists in performing timely and accurate diagnostic workup; (2) review of best practices for multidisciplinary management of amyloidosis, including prognostic variables and determinants of treatment response; and (3) update on new and emerging treatments in the management of light chain and amyloid transthyretin amyloidoses.

Limitations

This conference featured multidisciplinary discussion of cases, and learning points reflect the assessments by the involved experts/authors.

Implications

Identification and management of amyloidoses can be facilitated with a multidisciplinary approach and higher index of suspicion from cardiologists, nephrologists, and hemato-oncologists. Increased awareness of clinical presentations and diagnostic algorithms for amyloidosis subtyping will lead to more timely interventions and improved clinical outcomes.

The Clinical Characteristics of Immunoglobulin Light Chain Amyloidosis in the Chinese Population: A Systematic Scoping Review

Immunoglobulin light chain (AL) amyloidosis is the most common type of systemic amyloidosis in China and is associated with increased morbidity and a poor prognosis. However, the clinical characteristics of Chinese patients with AL amyloidosis have not been systematically investigated. This scoping review aimed to summarize the available literature regarding the clinical characteristics of patients with AL amyloidosis and identify potential knowledge gaps. We searched three electronic databases from inception to 7 February 2021. PICOS (Patient, Intervention, Comparison, Outcome and Study) design structure was used to formulate the data extraction. All statistical calculations and analyses were performed with R (version 3.6.0). Sixty-seven articles with 5022 patients were included. Results suggest Chinese patients were younger (57 years) at the time of diagnosis when compared with other patient populations and were predominantly male (61.2%). The time interval from the onset of symptoms to diagnosis was between 6 and 12 months. It was found that 41.1% of Chinese patients with AL amyloidosis were diagnosed with an advanced stage III disease when diagnosed, and 20.2% had a concurrent disease. The most involved organs were the kidneys (84.3%) and the heart (62.5%). In conclusion, our study shows some similarities and differences with other studies on the clinical characteristics of Chinese patients with AL amyloidosis, including the age at diagnosis, Mayo stage, and organ involvement. However, a nationwide epidemiological investigation is still needed to provide a comprehensive overview of this patient population in China.

A comprehensive overview of AL amyloidosis disease characteristics accumulated over two decades at a single referral center in Korea

BACKGROUND

Characteristics of AL amyloidosis across Asia are not well-described in the literature. Thus, we overviewed the incidence and disease characteristics of AL amyloidosis in Korea.

METHODS

We collected medical records of 302 AL amyloidosis patients and compared survival outcomes by predominant treatment strategy and at four time points: 1995-2003, 2004-2008, 2009-2013, and 2014-2018.

RESULTS

The median age was 62 years (36-83). One hundred forty-one patients were classified as stage III (26.3%) or IV (47.9%). The patients diagnosed between 2014 and 2018 survived longer than those diagnosed at other time points due to the introduction of bortezomib (p < 0.01). In addition, patients who received upfront ASCT survived longer than those who received salvage ASCT or chemotherapy alone (p < 0.01). However, most of the 85 patients who experienced early death within 6 months were older than 75 years, had BMI less than 20, and had a high disease burden.

CONCLUSIONS

The incidence of AL amyloid has increased and survival outcomes have improved gradually, most likely due to introduction of novel agents and upfront ASCT. However, not all patients are suitable for these potent treatment modalities, and avoiding early death within 6 months remains a challenge.

MALDI-TOF-MS for rapid screening analysis of M-protein in serum

Monoclonal immunoglobin (M-protein) is a serum biomarker for the diagnosis of plasma cell dyscrasias. Despite limitation of analytical sensitivity and resolution, serum protein electrophoresis and immunofixation electrophoresis are still the front-line tests for the detection of M-proteins. Herein, we developed a MALDI-TOF Mass spectrometry-based method for the screening test of M-proteins in human serum. Based on the unique mass signature of different immunoglobin isotypes, M-Proteins could be rapidly identified and typed. The method demonstrated with high analytical performance and throughput, rapid and simple, which could be a new choice for the diagnosis of plasma cell dyscrasias.

Systemic amyloidosis journey from diagnosis to outcomes: a twelve-year real-world experience of a single center in a middle-income country

BACKGROUND

Systemic amyloidosis is caused by the deposition of misfolded protein aggregates in tissues, leading to progressive organ dysfunction and death. Epidemiological studies originate predominantly from high-income countries, with few data from Latin America. Due to the non-specific clinical manifestations, diagnosing amyloidosis is often challenging and patients experience a long journey and delay in diagnosis. This study aimed to assess clinical and laboratory characteristics, the diagnostic journey, and outcomes of patients with biopsy-proven systemic amyloidosis diagnosed between 2009 and 2020 at a university referral center in a middle-income Latin American country. Patients´ medical records were retrospectively reviewed.

RESULTS

One hundred and forty-three patients were included. The median age at diagnosis was 60 years and 54% were male. Until the diagnosis, most of the patients (52%) were seen by at least 3 specialists, the main ones being: general practitioners (57%), nephrologists (45%), and cardiologists (38%). The most common manifestations were renal (54%) and cardiac (41%) disorders, and cachexia was seen in 36% of patients. In 72% of the cases, ≥ 2 biopsies were required until the final diagnosis. The median time from symptoms onset to diagnosis was 10.9 months, and most patients (75%) had ≥ 2 organs involved. The following subtypes were identified: AL (68%), ATTR (13%), AA (8%), AFib (4%), and inconclusive (7%). Median OS was 74.3 months in the non-AL subgroup and 18.5 months in AL. Among AL patients, those with advanced cardiac stage had the worst outcome [median OS 8.6 months versus 52.3 for stage III versus I-II, respectively (p < 0.001)]. AL subtype, cardiac involvement, and ECOG ≥ 2 were identified as independent risk factors for reduced survival.

CONCLUSIONS

Systemic amyloidosis is still an underdiagnosed condition and the delay in its recognition leads to poor outcomes. Medical education, better diagnostic tools, improvement in access to therapies, and establishment of referral centers may improve patient outcomes in middle-income countries.

Axillary Lymphadenopathy as an Initial Presentation of Systemic Amyloidosis: A Case Report and Literature Review

Amyloidosis rarely presents as localized lymphadenopathy. Various studies have elucidated the varied presentation and manifestations of this interesting disease. We reviewed the literature and found 36 cases of primary amyloidosis with lymph node enlargement as a presentation, and 17 of the 36 cases (47%) had systemic involvement on further work up. We describe a patient who presented with an isolated right axillary mass. Clinical examination and radiology were indicative of a lymph node enlargement with no evidence of malignancy in the breasts or lungs. Histopathological examination was indicative of amyloidosis. A further work up including serum, urine biochemistry, cardiac work up, bone marrow examination, and a kidney biopsy revealed systemic amyloidosis. Patient was treated with daratumumab and CyBorD (cyclophosphamide, bortezomib, and dexamethasone) followed by a stem cell transplantation. Patient is in remission for 1 year, at the time of submission of this report. Therefore, we conclude (1) systemic amyloidosis presenting as an isolated lymph node enlargement is rare, (2) a structured systemic work up is imperative for early diagnosis and proper management of amyloidosis, when there is an index of suspicion, and (3) use of novel therapeutic options such as CD38 + antibody (daratumumab) and stem cell transplant have positive impact on disease outcomes.

Real-world treatment patterns, costs, and outcomes in patients with AL amyloidosis: analysis of the Optum EHR and commercial claims databases

BACKGROUND

This study characterised real-world treatment patterns, clinical outcomes, and cost-of-illness in patients with light-chain (AL) amyloidosis.

METHODS

Data were extracted from the US-based Optum® EHR and Clinformatics® Data Mart (claims) databases (2008-2019) for patients newly diagnosed with AL amyloidosis and who initiated anti-plasma cell therapies. Healthcare resource utilisation (HCRU) and related costs were compared across lines of therapy (LOT). Incidences of cardiac and renal failure were evaluated using the Kaplan-Meier method.

RESULTS

About 1347 patients (EHR, n = 776; claims, n = 571) were included. Median age was 68 years; 56.8% were male. At initial diagnosis, 33.1% and 15.1% of patients had cardiac and renal failure, respectively. Most patients received bortezomib-containing treatment in LOT1 (69%); bortezomib-cyclophosphamide-dexamethasone was most common (26%). HCRU was similar across LOTs. Mean per-patient-per-month and per-patient-per-LOT costs were $19,343 and $105,944 for LOT1, $19,183 and $95,793 for LOT2, and $16,611 and $128,446 for LOT3, respectively. Costs were primarily driven by anti-plasma cell therapies, outpatient visits, and hospitalisations. The 5-year cardiac and renal failure rates following initial diagnosis were 64.5% and 39.0%, respectively.

CONCLUSION

AL amyloidosis is associated with substantial costs and suboptimal outcomes, highlighting the need for new therapeutic approaches to prevent organ deterioration, and reduce disease burden.

Noninvasive Diagnostics of Renal Amyloidosis: Current State and Perspectives

Amyloidoses is a group of diseases characterized by the accumulation of abnormal proteins (called amyloids) in different organs and tissues. For systemic amyloidoses, the disease is related to increased levels and/or abnormal synthesis of certain proteins in the organism due to pathological processes, e.g., monoclonal gammopathy and chronic inflammation in rheumatic arthritis. Treatment of amyloidoses is focused on reducing amyloidogenic protein production and inhibition of its aggregation. Therapeutic approaches critically depend on the type of amyloidosis, which underlines the importance of early differential diagnostics. In fact, the most accurate diagnostics of amyloidosis and its type requires analysis of a biopsy specimen from the disease-affected organ. However, absence of specific symptoms of amyloidosis and the invasive nature of biomaterial sampling causes the late diagnostics of these diseases, which leads to a delayed treatment, and significantly reduces its efficacy and patient survival. The establishment of noninvasive diagnostic methods and discovery of specific amyloidosis markers are essential for disease detection and identification of its type at earlier stages, which enables timely and targeted treatment. This review focuses on current approaches to the diagnostics of amyloidoses, primarily with renal involvement, and research perspectives in order to design new specific tests for early diagnosis.

Alterations of the gut microbiota in patients with immunoglobulin light chain amyloidosis

Background

Emerging evidence revealed that gut microbial dysbiosis is implicated in the development of plasma cell dyscrasias and amyloid deposition diseases, but no data are available on the relationship between gut microbiota and immunoglobulin light chain (AL) amyloidosis.

Methods

To characterize the gut microbiota in patients with AL amyloidosis, we collected fecal samples from patients with AL amyloidosis (n=27) and age-, gender-, and BMI-matched healthy controls (n=27), and conducted 16S rRNA MiSeq sequencing and amplicon sequence variants (ASV)-based analysis.

Results

There were significant differences in gut microbial communities between the two groups. At the phylum level, the abundance of Actinobacteriota and Verrucomicrobiota was significantly higher, while Bacteroidota reduced remarkably in patients with AL amyloidosis. At the genus level, 17 genera, including Bifidobacterium, Akkermansia, and Streptococcus were enriched, while only 4 genera including Faecalibacterium, Tyzzerella, Pseudomonas, and Anaerostignum decreased evidently in patients with AL amyloidosis. Notably, 5 optimal ASV-based microbial markers were identified as the diagnostic model of AL amyloidosis and the AUC value of the train set and the test set was 0.8549 (95% CI 0.7310-0.9789) and 0.8025 (95% CI 0.5771-1), respectively. With a median follow-up of 19.0 months, further subgroup analysis also demonstrated some key gut microbial markers were related to disease severity, treatment response, and even prognosis of patients with AL amyloidosis.

Conclusions

For the first time, we demonstrated the alterations of gut microbiota in AL amyloidosis and successfully established and validated the microbial-based diagnostic model, which boosted more studies about microbe-based strategies for diagnosis and treatment in patients with AL amyloidosis in the future.

Extracellular Volume Fraction Based on Cardiac Magnetic Resonance T1 Mapping: An Effective Way to Evaluate Cardiac Injury Caused by Cardiac Amyloidosis in Patients with Multiple Myeloma

Multiple myeloma (MM) is a hematological malignancy of plasma cell origin. Cardiac amyloidosis (CA) is a common form of heart damage caused by MM and is associated with a poor prognosis. This study was a prospective cohort study and was aimed at evaluating the clinical predictive value of extracellular volume fraction (ECV) based on cardiovascular magnetic resonance (CMR) T1 mapping for cardiac amyloidosis and cardiac dysfunction in MM patients. Fifty-one newly diagnosed MM patients in Zhongnan Hospital of Wuhan University were enrolled in the study. A total of 19 patients (19/51; 37.25%) developed CA. The basal ECV of CA group was significantly higher than that of the non-CA group ( $p<0.01$ ). Multivariate logistic regression analysis showed that basal ECV ( $\text{OR}=1.551$ , 95% CI 1.084-2.219, $p<0.05$ ) and LDH1 level ( $\text{OR}=1.150$ , 95% CI 1.010-1.310, $p<0.05$ ) were two independent risk factors for CA. Further study demonstrated that basal ECV in the heart failure group was significantly higher than that of the nonheart failure group ( $p<0.01$ ). Notably, ROC curve showed that basal ECV had a good predictive value for CA and heart failure, with AUC of 0.911 and 0.893 (all $p<0.01$ ), and the best cutoff values of 38.35 and 37.45, respectively. Taken together, basal ECV is a good predictor of CA and heart failure for MM patients.

Cardiac amyloidosis and left atrial appendage closure. The CAMYLAAC Study

INTRODUCTION AND OBJECTIVES

Transthyretin cardiac amyloidosis (ATTR-CA) patients often have atrial fibrillation and increased bleeding/thrombogenic risks. We aimed to evaluate outcomes of left atrial appendage closure (LAAC) compared with patients without a known diagnosis of CA.

METHODS

Comparison at long-term of patients diagnosed with ATTR-CA who underwent LAAC between 2009 and 2020 and those without a known diagnosis of CA.

RESULTS

We studied a total of 1159 patients. Forty patients (3.5%) were diagnosed with ATTR-CA; these patients were older and had more comorbidities, higher HAS-BLED and CHA₂DS₂-VASc scores, and lower left ventricular function. Successful LAAC was achieved in 1137 patients (98.1%) with no differences between groups. Regarding in-hospital and follow-up complications, there were no differences between the groups in ischemic stroke (5% vs 2.5% in those without a known diagnosis of CA; P=.283), hemorrhagic stroke (2.5% and 0.8% in the control group; P=.284), major or minor bleeding. At the 2-year follow-up, there were no significant differences in mortality (ATTR-CA: 20% vs those without known CA: 13.6%, 0.248); however, the at 5-year follow-up, ATTR-CA patients had higher mortality (40% vs 19.2%; P <.001) but this difference was unrelated to hemorrhagic complications or ischemic stroke.

CONCLUSIONS

LAAC could reduce the risk of bleeding complications and ischemic cerebrovascular events without increasing the rate of early or mid-term complications. Although long-term survival was impaired in ATTR-CA patients, it was comparable to that of patients without a known diagnosis of CA at the 2-year follow-up, suggesting that LAAC for patients with ATTR-CA might not be futile.