Serum monoclonal immunoglobulin light-chain detection differs between immunofixation electrophoresis methods in patients with AL amyloidosis.

Serum immunofixation electrophoresis (IFE) is often performed for screening monoclonal proteins (M proteins) in immunoglobulin light-chain amyloidosis (AL amyloidosis). However, the performance of serum IFE for detecting M protein in AL amyloidosis patients is often insufficient. In this study, we examined the detection rate of serum M protein in newly diagnosed AL amyloidosis patients and analyzed differences in M protein detection between IFE methods. Among 60 patients newly diagnosed with AL amyloidosis, 22 had undetectable serum M protein by IFE with the Epalyzer2 system. Samples with undetectable M protein had significantly lower involved serum-free light-chain (iFLC) and a smaller difference between involved and uninvolved serum-free light-chain (dFLC) values than samples with IFE-detectable monoclonal light chains. When samples that tested negative for M protein by the Epalyzer2 system were retested by IFE with the HYDRASYS 2 system, 50% had IFE-detectable monoclonal light chains. The IFE system and reagents used may affect serum monoclonal immunoglobulin light-chain detection in AL amyloidosis patients, especially those with low iFLC or low dFLC samples. More attention should be paid to the performance of IFE systems, since it may affect the diagnostic and therapeutic evaluation of AL amyloidosis patients.

Prognostic mortality factors in advanced light chain cardiac amyloidosis: A prospective cohort study.

AIMS: Predicting mortality in severe AL cardiac amyloidosis is challenging due to elevated biomarker levels and limited thresholds for stratifying severe cardiac damage. METHODS AND RESULTS: This prospective, observational, cohort study included de novo, confirmed cardiac AL amyloidosis patients at the Henri Mondor National Reference Centre. The goal was to identify predictors of mortality to enhance prognostic stratification and improve informed decision-making regarding therapy. Over the 12-year study period, among the 233 patients included, 133 were NYHA III-IV and 179 Mayo 2004 III. The independent predictors for mortality identified were hsTnT, NT-proBNP, cardiac output, and conjugated bilirubin. A novel prognostic, conditional stratification, Mondor amyloidosis cardiac staging (MACS) was developed with biomarker cut-off values for Stage 1: hsTnT ≤ 107 ng/L and NT-proBNP ≤ 3867 ng/L (n = 77; 33%); for stage 2 NT-proBNP > 3867 ng/L (n = 72; 30%). For stage 3, if troponin >107 ng/L, regardless of NT-proBNP then CB 4 µmol/L, was added (n = 41; 17.5%) and stage 4: CB > 4 µmol/L (n = 43; 18.5%). The median overall survival was 8 months 95% CI [2-24]. At 1 year, 102 (44%) patients died and the Kaplan-Meier median survival with MACS Stage 1 was not reached, while stage 2 was 15.2 months (95% CI [11-18]) and stage 3, 6.6 months (95% CI [1-13]). Notably, among European stage II patients, 17.1%, n = 8 were MACS stage 3 and European stage IIIb 21.4% (n = 23) were MACS stage 4. Importantly, among European stage IIIb patients 42.2% (n = 29) were classified MACS stage 4 and 12.5% n = 9 were only MACS stage 2. CONCLUSIONS: The Mondor prognostic staging system, including conjugate bilirubin may significantly improve prognostic stratification for patients with severe cardiac amyloidosis.

Thrombotic and bleeding complications in patients with AL amyloidosis.

Haemostatic abnormalities and deregulated coagulation are common complications in AL amyloidosis. The relevant risks of thromboembolic and haemorrhagic events have not been thoroughly evaluated. To describe clinically significant thrombotic/haemorrhagic events in 450 consecutive patients with AL amyloidosis. Venous thromboembolic events (VTEs) were reported in 6% and arterial embolic events (AEEs) in 5% of patients, respectively, during a 55-month median follow-up. Lower albumin, lower eGFR, higher BM infiltration, soft tissue involvement, IMiD-based therapy and prior thrombosis were associated with VTE risk. Prior thrombosis was the only independent prognostic variable (HR 9.3, p = 0.001). Coronary arterial disease, prior AEE, 24-h proteinuria and higher platelet counts were associated with AEE risk. Significant bleeding events were reported in 9%, and associated mortality was 19%. Liver involvement, higher serum creatinine and higher baseline VWF:Ag levels were linked to bleeding risk. Using competing risk analysis, the cumulative probability of thrombosis/bleeding was higher during the first year following diagnosis, but a stable lower risk for both events remained for the duration of follow-up. In AL amyloidosis patients, the risk of thrombotic/arterial embolic events is significant, but the bleeding risk is also high. A multiparametric assessment is required to initiate anti-thrombotic or anti-platelet therapy appropriately.

Biomarkers in AL Amyloidosis.

Systemic AL amyloidosis is a rare complex hematological disorder caused by clonal plasma cells which produce amyloidogenic immunoglobulins. Outcome and prognosis is the combinatory result of the extent and pattern of organ involvement secondary to amyloid fibril deposition and the biology and burden of the underlying plasma cell clone. Prognosis, as assessed by overall survival, and early outcomes is determined by degree of cardiac dysfunction and current staging systems are based on biomarkers that reflect the degree of cardiac damage. The risk of progression to end-stage renal disease requiring dialysis is assessed by renal staging systems. Longer-term survival and response to treatment is affected by markers of the underlying plasma cell clone; the genetic background of the clonal disease as evaluated by interphase fluorescence in situ hybridization in particular has predictive value and may guide treatment selection. Free light chain assessment forms the basis of hematological response criteria and minimal residual disease as assessed by sensitive methods is gradually being incorporated into clinical practice. However, sensitive biomarkers that could aid in the early diagnosis and that could reflect all aspects of organ damage and disease biology are needed and efforts to identify them are continuous.

Haematologic responses and survival do not significantly decrease with subsequent lines of therapy in systemic immunoglobulin light chain amyloidosis: results from an analysis of real-world longitudinal data.

Systemic immunoglobulin light chain amyloidosis (AL) is an incurable disorder, and the natural history is incompletely understood. In this study, we describe its natural history based on an analysis of real-world longitudinal data. All patients seen at the National Amyloidosis Centre, UK, between February 2010 and August 2019 and treated with up-front bortezomib are included. In all, 1 276 patients received the first-line treatment; 259, 85, and 32 patients received second, third, and fourth treatment lines, respectively. Among patients requiring further treatment after the first line, 77·2% started the second line within two years of the first line; 50·5%, 50·6%, 40·1% and 40·6% of patients had achieved at least very good partial response after the first, second, third and fourth treatment lines. Median overall survival (OS) from first, second, third and fourth lines was 45 months, 56 months, 37 months and not reached, respectively (P = 0·109). In summary, although relapses occur in AL amyloidosis, the outcomes and responses do not worsen with each subsequent relapse, making it attractive to design therapeutics with curative intent.

Impact of early response on outcomes in AL amyloidosis following treatment with frontline Bortezomib.

The outcomes in systemic AL amyloidosis are dependent on the depth of haematologic response. However, there is limited data on the impact of the speed of response on outcomes. Here we report the impact of speed of response in a cohort of AL patients treated with upfront Bortezomib. Patients seen from February 2010 until August 2019 are included in the present analysis. 1194 & 1133 patients comprised the ITT and 1-month landmark cohorts. In the landmark cohort, 137 (11.5%), 270 (22.6%), 252 (21.1%) and 352 (31.1%) patients had a CR, VGPR, PR and NR at 1-month. Patients with ≥ VGPR at 1-month had significantly better survival (median not reached; at the end of 1, 2, 5,10 years, 87%/92%, 83%/87%, 68%/72% and 63%/58% of patients in CR/VGPR, respectively, were alive) compared to those with a PR (median OS 60 months) or NR (median OS 32 months) (p < 0.005). At 1-month, patients with CR and iFLC < 20 mg/l had a significantly better survival compared to CR and iFLC > 20 mg/l (p = 0.005). Reaching ≥ VGPR at 1-month significantly improved survival in all Mayo disease stages. In conclusion, patients achieving an early deep haematologic response have a significantly superior survival irrespective of cardiac involvement.

Changes in patient-reported outcomes in light chain amyloidosis in the first year after diagnosis and relationship to NT-proBNP change.

We conducted a prospective cohort study in newly diagnosed systemic light chain (AL) amyloidosis patients (N = 59) to study patient-reported outcomes (PROs) through the first year. The median age was 68 years with 42% female, 8% Black, and 78% lambda subtype. Organ involvement was cardiac in 66%, renal in 58%, with 25% having 3 or greater organs involved. Between baseline and 3 months, all PROMIS®-29 domain scores worsened by 0.4-4.1 points except anxiety which improved by 2.1 points. By 1 year, scores improved compared to the greatest decline at 3 months, most statistically significant for global physical health, physical function, and fatigue. On stage-adjusted survival analysis, in addition to baseline global physical and mental health, domains measuring physical function, fatigue, anxiety, depression, and social roles were associated with 1-year survival. At 1 year, PROMIS measures were associated with NT-proBNP changes and hematologic response. Among patients with an NT-proBNP response, the improvement was seen in physical function, social roles, global mental health, and anxiety. Among patients with an NT-proBNP progression, worsening was seen with anxiety, depression, sleep, and global mental health. Measuring and tracking PROs in patients with AL amyloidosis is important and these important outcomes can be used as correlative endpoints in clinical care/research.

Serum Hevylite® assay in the differential diagnosis of patients with high suspicion of AL Amyloidosis.

INTRODUCTION: AL amyloidosis (AL) is a malignant form of plasma cell dyscrasia (PCD). It is insidious, and its end-organ damage can mimic that of common diseases. At diagnosis, routine tests for monoclonal protein are insufficient for the differential diagnosis. We hypothesized that Hevylite® (HLC) isotype patterns may help discriminate between AL and benign PCD states. METHODS: Serum samples of patients with a high clinical suspicion of AL were prospectively tested for IgGκ, IgGλ, IgAκ, IgAλ, IgMκ, and IgMλ concentrations and ratios using Hevylite® assays in a blinded manner. The results were correlated with the final diagnosis. RESULTS: Of the 99 samples analyzed, 46 were newly diagnosed AL, and the majority, 38 (82.6%), presented with suppression of at least one HLC isotype. Of the 53 benign PCD patients, 36 (67.9%) presented with elevation of at least one HLC isotype. By multivariate analysis, Hevylite® was the best independent test predictor of AL amyloidosis. HLC suppression had an odds ratio (OR) of 14.591, and elevation an OR of 10.149, and thus were significant variables in the diagnosis and exclusion of AL. Furthermore, patients with both HLC suppression, together with no elevation, had an OR of 316.69 to be diagnosed with AL rather than a benign PCD. CONCLUSIONS: Hevylite® HLC analysis for Ig isotypes patterns offers an effective non-invasive tool in the evaluation of patients with high suspicion of AL and may assist further explorative decisions for diagnosis.

Predictors of cardiac involvement and survival in patients with primary systemic light-chain amyloidosis: roles of the clinical, chemical, and 3-D speckle tracking echocardiography parameters.

BACKGROUND: Light-chain (AL) amyloidosis is the most common type of systemic amyloidosis with poor prognosis. Currently, the predictors of cardiac involvement and prognostic staging systems are primarily based on conventional echocardiography and serological biomarkers. We used three-dimensional speckle tracking echocardiography (STE-3D) measurements of strain, hypothesizing that it could detect cardiac involvement and aid in prediction of mortality. METHODS: We retrospectively analysed 74 consecutive patients with biopsy-proven AL amyloidosis. Among them, 42 showed possible cardiac involvement and 32 without cardiac involvement. LV global longitudinal strain (GLS), global radial strain, global circumferential strain and global area strain (GAS) measurements were obtained. RESULTS: The GLS and GAS were considered significant predictors of cardiac involvement. The cut-off values discriminating cardiac involvement were 16.10% for GLS, 32.95% for GAS. During the median follow-up of 12.5 months (interquartile range 4-25 months), 20 (27%) patients died. For the Cox proportional model survival analysis, heart rate, cardiac troponin T, NT-proBNP levels, E/e', GLS, and GAS were univariate predictors of death. Multivariate Cox model showed that GLS ≤ 14.78% and cardiac troponin T ≥ 0.049 mg/l levels were independent predictors of survival. CONCLUSIONS: STE-3D measurements of LV myocardial mechanics could detect cardiac involvement in patients with AL amyloidosis; GLS and cardiac biomarkers can provided prognostic information for mortality prediction.

Comparison of the current renal staging, progression and response criteria to predict renal survival in AL amyloidosis using a Mayo cohort.

Three sets of criteria (International Society of Amyloidosis [ISA], Palladini and Kastritis) were independently developed for staging, progression and response criteria to predict renal survival in patients with AL amyloidosis. We evaluated these criteria using a cohort of 495 newly diagnosed AL amyloidosis patients with renal involvement using time to event competing risk analysis at baseline, 3, 6 and 12 months after treatment. Only Palladini and Kastritis had a staging system and both predicted a higher risk of end stage renal disease (ESRD) in the stage III vs stage I patients but only the Palladini model was predictive for stage II patients. At 3 months, risk of ESRD was significantly higher for Palladini and ISA renal progression (hazard ratio [HR] 2.8 [95% CI: 1.5-5.3, p = .001] and 2.5 [CI: 1.4-4.6, p = .004, respectively]), but renal response was not significantly protective; conversely, the risk of ESRD was not significantly higher for the Kastritis renal progression, but was significantly protective for the Kastritis renal responders (HR 0.38 [95% CI: 0.17-0.84], p = .017). Both progression and response with ISA, Palladini and Kastritis criteria were predictive of ESRD at 6 months and 12 months. While the Palladini staging criteria at baseline, and the ISA and Palladini criteria for progression at 3 months performed better than the Kastritis criteria at baseline and 3 months post-treatment, the Kastritis criteria performed better for response 3 months after treatment. All three sets of criteria performed well at and after 6 months post-treatment. These differences are important when choosing endpoints for clinical trials.

Timing and impact of a deep response in the outcome of patients with systemic light chain (AL) amyloidosis.

A rapid and deep haematologic response is fundamental in order to improve outcomes of patients with AL amyloidosis. We evaluated the impact of timing and depth of haematologic response at early time points (at 1 and 3 months from the start of therapy) in 227 consecutive previously untreated AL patients, who received bortezomib-based primary therapy. After 1 month of therapy, 30.5% had ≥VGPR, 28% PR and 36% no response (NR), with 11% having iFLC <20 mg/L and 15% dFLC <10 mg/L. Deep haematologic response at 1 month (either ≥VGPR or iFLC <20 mg/L or dFLC <10 mg/L), was associated with a high organ response rate. The survival of patients with ≥VGPR was significantly better than those with PR and NR at 1-month landmark (p < .001) but this benefit was mainly driven by those with iFLC <20 mg/L. The depth of haematologic response at 1 month was significant across all Mayo stages. At 3 months, 46% of the patients had not significantly improved the depth of their response but even patients that improved their response from an iFLC ≥20 mg/L at 1 month to iFLC <20 mg/L at 3 months still had inferior outcome to those with an early deep response. Thus, in patients with AL amyloidosis, a very rapid and deep response is crucial, especially for those at high risk, targeting very low FLC levels within the first month of therapy.

Next generation flow cytometry for MRD detection in patients with AL amyloidosis.

The treatment of AL amyloidosis aims to eradicate the plasma cell clone and eliminate toxic free light chain production. Only in a minority of patients the plasma cell clone is completely eradicated; residual light chain production may still exist while clonal relapse may occur. We used sensitive next-generation flow cytometry (NGF) to detect minimal residual disease (MRD) in AL amyloidosis patients at complete haematologic response. MRD evaluation was feasible in 51 of 52 (98%) tested patients and at a median sensitivity of 2.3 × 10-6 MRD was undetectable in 23 (45%). An organ response occurred in 86% of MRDneg vs 77% in MRDpos; renal response in 15/17(88%) of MRDneg vs in 14/16(87.5%) of MRDpos and cardiac response in 10/10(100%) of MRDneg vs 11/15(73%) of MRDpos patients. After a median follow-up of 24 months post MRD testing, no MRDneg patient had a haematologic relapse vs 6/28(21%) MRDpos (p = .029). Pooling haematologic and organ progressions, 9 (32%) MRDpos patients had disease progression vs only 1 (4%) MRDneg patient (p = .026). In conclusion, MRD detection using NGF has profound clinical implications, so that AL patients with undetectable MRD have a very high probability of organ response and a very low probability of haematologic relapse.

The diagnostic challenges of cardiac amyloidosis: A practical approach to the two main types.

Systemic amyloidosis of the immunoglobulin light-chain (AL) or transthyretin type (ATTR) is a multisystem protein deposition disease that often involves the heart. Delays in diagnosis are very common and can have detrimental consequences on patient outcomes. Because both major types can now be distinguished quickly and treated effectively, clear approaches are required. There have been advances in radioisotope scintigraphy, monoclonal protein testing and mass spectrometry for typing that need coordinated application. We have entered an era in which rapid diagnosis and ready therapy will save lives, therefore we must develop coherent approaches to this multisystem disease. The prognosis for AL has improved significantly with the incorporation of novel agents such as proteasome inhibitors, immunomodulators and monoclonal antibodies against plasma cells. Multiple independent studies have demonstrated the efficacy of these agents in AL, though tolerability can become an issue with dose reductions required in many cases. Median overall survival for patients achieving complete responses after stem cell transplant and consolidation exceeds a decade. The prognosis for ATTR, both age-related wild-type (ATTRwt) and hereditary due to variants of transthyretin (ATTRv), has improved as well due to the availability of the stabilizer tafamidis and the RNA-interference agents patisiran and inotersen. In both AL and ATTR, with elimination or suppression of the pathologic amyloid-forming protein, symptomatic involvement of the heart, kidneys and peripheral nervous system can improve as well. In this review, we present the current state of diagnosing and treating the two major types of systemic amyloidosis, emphasizing the coherent clinical application of the new tools and treatments. Implementation of the approaches we provide will enable rapid identification of amyloid type and rational selection of therapy.

A multi-modal diagnostic model improves detection of cardiac amyloidosis among patients with diagnostic confirmation by cardiac biopsy.

BACKGROUND: Timely recognition of cardiac amyloidosis is clinically important, but the diagnosis is frequently delayed. OBJECTIVES: We sought to identify a multi-modality approach with the highest diagnostic accuracy in patients evaluated by cardiac biopsy, the diagnostic gold standard. METHODS: Consecutive patients (N = 242) who underwent cardiac biopsy for suspected amyloidosis within an 18-year period were retrospectively identified. Cardiac biomarker, ECG, and echocardiography results were examined for correlation with biopsy-proven disease. A prediction model for cardiac amyloidosis was derived using multivariable logistic regression. RESULTS: The overall cohort was characterized by elevated BNP (median 727 ng/mL), increased left ventricular wall thickness (IWT; median 1.7 cm), and reduced voltage-to-mass ratio (median 0.06 mm/[g/m2]). One hundred and thirteen patients (46%) had either light chain (n = 53) or transthyretin (n = 60) amyloidosis by cardiac biopsy. A prediction model including age, relative wall thickness, left atrial pressure by E/e', and low limb lead voltage (<0.5 mV) showed good discrimination for cardiac amyloidosis with an optimism-corrected c-index of 0.87 (95% CI 0.83-0.92). The diagnostic accuracy of this model (79% sensitivity, 84% specificity) surpassed that of traditional screening parameters, such as IWT in the absence of left ventricular hypertrophy on ECG (98% sensitivity, 20% specificity) and IWT with low limb lead voltage (49% sensitivity, 91% specificity). CONCLUSION: Among patients with an advanced infiltrative cardiomyopathy phenotype, traditional biomarker, ECG, and echocardiography-based screening tests have limited individual diagnostic utility for cardiac amyloidosis. A prediction algorithm including age, relative wall thickness, E/e', and low limb lead voltage improves the detection of cardiac biopsy-proven disease.

Management of AL amyloidosis in 2020.

In amyloid light chain (AL) amyloidosis, a small B-cell clone, most commonly a plasma cell clone, produces monoclonal light chains that exert organ toxicity and deposit in tissue in the form of amyloid fibrils. Organ involvement determines the clinical manifestations, but symptoms are usually recognized late. Patients with disease diagnosed at advanced stages, particularly when heart involvement is present, are at high risk of death within a few months. However, symptoms are always preceded by a detectable monoclonal gammopathy and by elevated biomarkers of organ involvement, and hematologists can screen subjects who have known monoclonal gammopathy for amyloid organ dysfunction and damage, allowing for a presymptomatic diagnosis. Discriminating patients with other forms of amyloidosis is difficult but necessary, and tissue typing with adequate technology available at referral centers, is mandatory to confirm AL amyloidosis. Treatment targets the underlying clone and should be risk adapted to rapidly administer the most effective therapy patients can safely tolerate. In approximately one-fifth of patients, autologous stem cell transplantation can be considered up front or after bortezomib-based conditioning. Bortezomib can improve the depth of response after transplantation and is the backbone of treatment of patients who are not eligible for transplantation. The daratumumab+bortezomib combination is emerging as a novel standard of care in AL amyloidosis. Treatment should be aimed at achieving early and profound hematologic response and organ response in the long term. Close monitoring of hematologic response is vital to shifting nonresponders to rescue treatments. Patients with relapsed/refractory disease are generally treated with immune-modulatory drugs, but daratumumab is also an effective option.