Amyloidosis Patients Research Articles

Kinetic analysis of cardiac dynamic 18F-Florbetapir PET in healthy volunteers and amyloidosis patients: A pilot study

ObjectivesThis study aimed to explore the potential of full dynamic PET kinetic analysis in assessing amyloid binding and perfusion in the cardiac region using 18F-Florbetapir PET, establishing a quantitative approach in the clinical assessment of cardiac amyloidosis disease. Materials & methodsThe distribution volume ratios (DVRs) and the relative transport rate constant (R1), were estimated by a pseudo-simplified reference tissue model (pSRTM2) and pseudo-Logan plot (pLogan plot) with kidney reference for the region of interest-based and voxel-wise-based analyses. The parametric images generated using the pSRTM2 and linear regression with spatially constrained (LRSC) algorithm were then evaluated. Semi-quantitative analyses include standardized uptake value ratios at the early phase (SUVREP, 0.5–5 min) and late phase (SUVRLP, 50–60 min) were also calculated. ResultsTen participants [7 healthy controls (HC) and 3 cardiac amyloidosis (CA) subjects] underwent a 60-min dynamic 18F-Florbetapir PET scan. The DVRs estimated from pSRTM2 and Logan plot were significantly increased (HC vs CA; DVRpSRTM2: 0.95 ± 0.11 vs 2.77 ± 0.42, t’(2.13) = 7.39, P = 0.015; DVRLogan: 0.80 ± 0.12 vs 2.90 ± 0.55, t’(2.08) = 6.56, P = 0.020), and R1 were remarkably decreased in CA groups, as compared to HCs (HC vs CA; 1.08 ± 0.37 vs 0.56 ± 0.10, t’(7.63) = 3.38, P = 0.010). The SUVREP and SUVRLP were highly correlated to R1 (r = 0.97, P < 0.001) and DVR(r = 0.99, P < 0.001), respectively. The DVRs in the total myocardium region increased slightly as the size of FWHM increased and became stable at a Gaussian filter ≥6 mm. The secular equilibrium of SUVR was reached at around 50-min p.i. time. ConclusionThe DVR and R1 estimated from cardiac dynamic 18F-Florbetapir PET using pSRTM with kidney pseudo-reference tissue are suggested to quantify cardiac amyloid deposition and relative perfusion, respectively, in amyloidosis patients and healthy controls. We recommend a dual-phase scan: 0.5–5 min and 50–60 min p.i. as the appropriate time window for clinically assessing cardiac amyloidosis and perfusion measurements using 18F-Florbetapir PET.

High-Sensitivity Cardiac Troponin T to Exclude Cardiac Involvement in TTR Variant Carriers and ATTRv Amyloidosis Patients

(1) Background: Individuals carrying a pathogenic transthyretin gene variant (TTRv) are at high risk for developing hereditary transthyretin (ATTRv) amyloidosis and are routinely screened for the development of cardiomyopathy (ATTRv-CM). This study aims to evaluate whether the cardiac biomarkers N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) can be used to rule out ATTRv-CM. (2) Methods: In this retrospective case-control study, data from 46 ATTRv-CM patients and 101 TTRv carriers and ATTRv amyloidosis patients without cardiomyopathy were included. Binary logistic regression models were used to assess the ability of NT-proBNP and hs-cTnT to predict the diagnosis of ATTRv-CM. An optimal cutoff for the relevant biomarker(s) was determined based on a sensitivity of ≥99% and the highest possible percentage of additional tests avoided (%ATA) in the index dataset. (3) Results: Hs-cTnT demonstrated the highest predictive capabilities for ATTRv-CM. The addition of NT-proBNP did not improve the predictive model. A hs-cTnT cutoff of &lt;6 ng/L resulted in a 97% sensitivity and a negative predictive value of 95% with a %ATA of 30% in the validation dataset. (4) Conclusion: In conclusion, hs-cTnT is a useful biomarker for excluding cardiac involvement in TTRv carriers and ATTRv amyloidosis patients and it has the potential to prevent unnecessary diagnostic procedures.

Quantitative muscle ultrasound as a disease biomarker in hereditary transthyretin amyloidosis with polyneuropathy.

There is an increasing need for a reproducible and sensitive outcome measure in patients with hereditary transthyretin amyloidosis (ATTRv) with polyneuropathy (PN) due to the emergence of disease modifying therapies. In the current study, we aimed to investigate the role of quantitative muscle ultrasound (QMUS) as a disease biomarker in ATTRv-PN. Twenty genetically confirmed ATTRv amyloidosis patients (nine symptomatic, 11 pre-symptomatic) were enrolled prospectively between January to March 2023. Muscle ultrasound was performed on six muscles at standardized locations. QMUS parameters included muscle thickness (MT) and muscle echo intensity (EI). Twenty-five age- and sex-matched healthy controls were recruited for comparison. Significant QMUS parameters were correlated with clinical outcome measures. Muscle volume of first dorsal interosseus (FDI) muscle [measured as cross-sectional area (CSA)] was significantly lower in symptomatic patients compared to healthy controls and pre-symptomatic carriers (98.3 ± 58.0 vs. 184.4 ± 42.5 vs. 198.3 ± 56.8, p < 0.001). EI of biceps and FDI for symptomatic ATTRv-PN patients were significantly higher compared to the other two groups (biceps: 76.4 ± 10.8 vs. 63.2 ± 11.5 vs. 59.2 ± 9.0, p = 0.002; FDI: 48.2 ± 7.5 vs. 38.8 ± 7.5 vs. 33.0 ± 5.3, p < 0.001). CSA of FDI and EI of biceps and FDI correlated with previous validated outcome measures [polyneuropathy disability score, neuropathy impairment score, Karnofsky performance scale, Rasch-built overall disability scale, European quality of life (QoL)-5 dimensions and Norfolk QoL questionnaire-diabetic neuropathy]. QMUS revealed significant difference between ATTRv amyloidosis patients and healthy controls and showed strong correlation with clinical outcome measures. QMUS serves as a sensitive and reliable biomarker of disease severity in ATTRv-PN.

Screening for Occult Transthyretin Amyloidosis in Patients with Severe Aortic Stenosis and Amyloid Red Flags

Aims: The optimal strategy to identify transthyretin-type cardiac amyloidosis (ATTR-CA) in patients with aortic stenosis (AS) is still unclear. This study aimed to investigate if targeted screening for ATTR-CA in patients with severe AS and amyloid red flags is associated with higher detection rates. Methods: The study prospectively enrolled patients ≥65 years with severe AS. Patients who fulfilled ≥1 major (carpal tunnel syndrome (CTS), ruptured biceps tendon, spinal stenosis, N-terminal pro B-type natriuretic peptide ≥1000 pg/mL, cardiac troponin &gt;99th percentile) or ≥2 minor criteria (diastolic dysfunction ≥2 grade/lateral e’ &lt;10 cm/s, atrial fibrillation, atrioventricular conduction disease/pacemaker) received bone scintigraphy and biochemical analysis for light chain amyloidosis. Hypertensive patients (&gt;140/90 mmHg) and those with interventricular septal thickness (IVSd) ≤13 mm were excluded. Results: Overall, 264 patients were screened, of whom 85 were included in the analysis. Tracer uptake Perugini grade ≥1 was detected in nine patients (11%). An endomyocardial biopsy was additionally performed in four of nine patients, yielding a prevalence of 7% (n = 6). All patients with dual AS-ATTR were male. Syncope was more commonly reported in AS-ATTR patients (50% vs. 6%, p = 0.010), who also tended to have more severe hypertrophy (IVSd of 18 vs. 16 mm, p = 0.075). Pericardial effusion and CTS were more common in patients with dual pathology (67% vs. 8%, p &lt; 0.001, and 83% vs. 24%, p = 0.003, respectively). Conclusion: Targeted screening for ATTR-CA in patients with AS and amyloid red flags does not yield higher detection rates than those reported previously in all comers with AS.

Impact of amyloidosis on the outcomes of patients with coronary artery disease: A nationwide analysis

Background: Amyloidosis is a disease of increasing interest, primarily due to its high prevalence and advances in diagnostic and therapeutic options. It is known to be coexistent with a significant number of aortic stenosis patients (AS). Various studies have been done to evaluate its role in the clinical outcomes of AS. However, there is a lack of similar data on coronary artery disease (CAD) patients. Methods: We conducted a cross-sectional cohort study using the nationwide inpatient sample (NIS) 2018–19. We included 305,675 adult inpatients with CAD and further divided by the presence of a co-diagnosis of amyloidosis. A logistic regression model was used to evaluate the odds ratio (OR) of the association between in-hospital mortality in CAD inpatients with and without amyloidosis and other comorbidities. Results: The prevalence of amyloidosis in the total inpatient population with CAD was 7.3%, with the majority of the patients being in the older age group (mean age: 66.88 years), males (64.2%), and white (70.9%). Interestingly, the amyloidosis cohort had a higher prevalence of hypertension (89.3% vs. 85.1%). CAD inpatients with amyloidosis were noted to have higher in-hospital mortality (1.6% vs. 0.9%) with an OR of 1.87 (95% CI 1.66–2.11, p &lt;0.001). These patients also had a higher length of stay (6.66 days vs. 4.68 days), total charges ($156,149.76 vs. $119,442.71), and major loss of function (56.5% vs. 30.5%). Amongst patients with CAD and amyloidosis, household income below the 50th percentile was a risk factor for in-hospital mortality (OR 1.5, 95% CI 1.39–1.63, p &lt;0.001). Conclusions: Results from our study show that CAD inpatients who have comorbid amyloidosis have worse outcomes compared to those who do not. Further studies are needed to determine the etiology behind these outcomes and thus guide the management of stable CAD in amyloidosis patients.

Structural polymorphism of amyloid fibrils in ATTR amyloidosis revealed by cryo-electron microscopy

ATTR amyloidosis is caused by the deposition of transthyretin in the form of amyloid fibrils in virtually every organ of the body, including the heart. This systemic deposition leads to a phenotypic variability that has not been molecularly explained yet. In brain amyloid conditions, previous studies suggest an association between clinical phenotype and the molecular structures of their amyloid fibrils. Here we investigate whether there is such an association in ATTRv amyloidosis patients carrying the mutation I84S. Using cryo-electron microscopy, we determined the structures of cardiac fibrils extracted from three ATTR amyloidosis patients carrying the ATTRv-I84S mutation, associated with a consistent clinical phenotype. We found that in each ATTRv-I84S patient, the cardiac fibrils exhibited different local conformations, and these variations can co-exist within the same fibril. Our finding suggests that one amyloid disease may associate with multiple fibril structures in systemic amyloidoses, calling for further studies.

Immune checkpoint expression patterns on T cell subsets in light-chain amyloidosis: VISTA, PD-1, and TIGIT as potential therapeutic targets.

Amyloid light chain (AL) amyloidosis is a rare plasma cell dyscrasia with dismal prognosis. This study aims to investigate the T-cell immune checkpoint expression patterns in systemic AL amyloidosis and its relationship with clinicobiological traits. We examined the frequencies of V-domain immunoglobulin suppressor of T cell activation+ (VISTA+), programmed cell death 1+ (PD-1+), T cell immunoglobulin and mucin-domain-containing-3+ (Tim-3+), T cell immunoreceptor with Ig and ITIM domains+ (TIGIT+) T cells in peripheral blood (PB) and bone marrow (BM) from 19 patients with newly diagnosed AL amyloidosis. Patients with AL amyloidosis had significantly higher percentages of VISTA+ and PD-1+ T cells in PB than healthy individuals (HIs), with no statistical differences in BM. The percentages of some double-positive T cells in PB were also considerably higher in AL amyloidosis than those in HIs. Additionally, the patients with renal involvement had more PD-1+ and TIGIT+ T cells than the patients without, and PD-1+CD3+%, PD-1+CD4+%, PD-1+Treg% were positively correlated with 24-hour proteinuria levels. Furthermore, the AL amyloidosis patients had higher counts of PD-1+ Treg in PB than multiple myeloma (MM) patients, while the MM patients had higher counts of TIGIT+ T cells than AL amyloidosis patients. Collectively, this is the first report of elevated proportions of VISTA+ and PD-1+ T cells in PB of AL amyloidosis patients, indicating an immunosuppressive milieu, and the increased PD-1+ and TIGIT+ T cells were associated with renal damage. VISTA, PD-1, and TIGIT may be potential targets for reversing T-cell exhaustion in AL amyloidosis.

Assessment of Tp-Te interval in patients with cardiac AL amyloidosis.

Prolonged Tp-Te interval is strongly associated with fatal ventricular arrhythmias and mortality. This association has been demonstrated in various diseases. However, the current literature does not give any information on Tp-Te interval in cardiac amyloid light-chain (AL) amyloidosis. We retrospectively screened 116 cardiac AL amyloidosis patients and 35 patients were included in the study. Demographic, laboratory, 12-lead electrocardiographic (QTc, Tp-Te V1-V6) and transthoracic echocardiographic data of the patients were analysed and compared with 35 healthy controls. QTc and Tp-Te V2-V5 were significantly prolonged in the cardiac AL amyloidosis group (p < 0.05). Also, there was a positive and statistically significant correlation between the parameters of QTc and Tp-Te V3-V6, and also between the parameters of interventricular septum thickness at enddiastole and Tp-Te V2-V5. We present the first strong evidence of prolonged Tp-Te intervals in patients with cardiac AL amyloidosis. There may also be a relationship between prolonged Tp-Te interval and the development of arrhythmia in this patient group, as in some other groups. There is a need for prospective studies examining the relationship of prolonged Tp-Te interval with arrhythmias and its prognostic significance in cardiac AL amyloidosis.

Biomarkers of axonal damage to favor early diagnosis in variant transthyretin amyloidosis (A-ATTRv)

Early identification of ATTRv amyloidosis disease onset is still often delayed due to the lack of validated biomarkers of this disease. Light chain neurofilament (NfL) have shown promising results in early diagnosis in this disease, but data is still needed, including with alternative measuring methods. Our aim was to study the levels of NfL measured by ELISA. Furthermore, interstitial matrix metalloproteinase type 1 (MMP-1) serum levels were measured as a potential new biomarker in ATTRv. Serum NfL and MMP-1 were measured using ELISA assays in 90 participants (29 ATTR-V30M patients, 31 asymptomatic V30M-TTR variant carriers and 30 healthy controls). Median NfL levels among ATTRv amyloidosis patients were significantly higher (116 pg/mL vs 0 pg/mL in both comparison groups). The AUC comparing ATTRv amyloidosis patients and asymptomatic carriers was 0.90 and the NfL concentration of 93.55 pg/mL yielded a sensitivity of 79% and a specificity of 87%. NfL levels had a significant positive correlation with NIS values among patients. We found a negative significant correlation between eGFR and NfL levels. Finally, MMP1 levels were not different between groups. Evidence of NfL use for early diagnosis of ATTR-PN amyloidosis is growing. ELISA seems a reliable and available technique for it quantification. Decreased GFR could influence NfL plasma levels.

Red flags of cardiac amyloidosis in patients with spinal stenosis and yellow ligament hypertrophy

IntroductionStudies addressing the prevalence of cardiac amyloidosis (CA) among patients with spinal stenosis (SS) are lacking. The identification of the red flags (RF) of CA could lead to early detection of cases of CA. The primary objective of this study was to address the prevalence of RF of CA among patients with SS. MethodsTransversal study including consecutive cases with SS and yellow ligament hypertrophy (YLH). A clinical assessment thar included electrocardiogram, echocardiogram anf urine and blood test was performed. A clinical suspicion of CA was defined by the presence of left ventricular hypertrophy plus any RF. Results103 patients with SS and YLH were assessed. The prevalence of RF was high: heart failure: 18.4%; aortic stenosis: 1.9%; carpal tunnel syndrome: 7.8%; bicipital tendon rupture: 1.9%; arterial hypotension: 17.4%; polyneuropathy symptoms: 51.5%; pseudoinfarction patten: 3.9%; low voltages: 15.5%; conduction abnormalities: 15.5%; decreased longitudinal strain: 25.3%; apical sparing pattern: 3.9%. The 57.3% of the cohort met the CA suspicion criteria. ConclusionThe prevalence of RF of CA is high among patients with SS and YLH. A high proportion of patients met the CA suspicion criteria.

The Most Predictive Red Flags for Suspecting Cardiac Amyloidosis in Patients with Heart Failure with Preserved Ejection Fraction.

Cardiac amyloidosis (CA) is a cardiomyopathy characterized by amyloid infiltration in the myocardium. Transthyretin cardiac amyloidosis (TTR-CA), commonly presenting as heart failure with preserved ejection fraction (HFpEF), was the focus of our study, which aimed to identify red flags that heighten suspicion of CA in HFpEF patients. We prospectively included patients diagnosed with HFpEF. All patients were assessed for TTR-CA red flag features, cardiac and extra-cardiac, as outlined in the 'Diagnosis and Treatment of Cardiac Amyloidosis: A Position Statement of the European Society of Cardiology.' Technetium-99m pyrophosphate (99mTc-PYP) cardiac scintigraphy was performed in 167 HFpEF patients suspected of having TTR-CA. Patients testing positive and negative for TTR-CA were compared based on these red flag features. Out of 167 HFpEF patients, 19 (11.3%) were diagnosed with TTR-CA. In the TTR-CA group, 17 (89.5%) patients were 65 years or older. The presence of three or more red flags differentiated the TTR-CA positive and negative groups (P = 0.040). Features such as low voltage and pseudo infarct patterns were more prevalent in the TTR-CA group (P < 0.001 and P < 0.048, respectively). Left ventricular global longitudinal strain (LV-GLS) was lower in the TTR-CA positive group (P < 0.001). Multivariate analysis identified four variables-older age, pseudo infarct pattern, low/decreased QRS voltage, and LV-GLS-as strong, independent predictors of TTR-CA, with significant odds ratios (ORs) of 7.8, 6.8, 16.9, and 1.2, respectively. In this study, TTR-CA etiology occurs in approximately one in every ten HFpEF patients. The presence of three or more red flags increases the likelihood of TTR-CA. Older age, pseudo infarct pattern, low/decreased QRS voltage, and reduced LV-GLS are the most significant red flags indicating TTR-CA in HFpEF patients.

A prospective comparative study of efficacy and safety of 15% trichloroacetic acid peel, 35% glycolic acid peel and Q-switched Nd-YAG laser in patients of macular amyloidosis.

The unappealing appearance of skin in macular amyloidosis (MA) interferes with the patient's quality of life, and treating the condition has been challenging. To compare the efficacy and safety of 15% trichloroacetic acid (TCA) peel, 35% glycolic acid (GA) peel, and Q-switched Nd-YAG Laser in MA. Open, prospective study was conducted over 2 years, where after fulfilling the criteria, randomization was done into three groups. Group A: 15% TCA peel; Group B: 35% GA peel; Group C: Q-switched Nd-YAG Laser. Procedures were repeated at monthly intervals for six sittings. On each visit, patients were scored on the following parameters: color score, visual analog score (VAS), physician global assessment (PGA) scale, subjective improvement, and adverse effects. A total of 75 patients (25 patients in each group) completed the treatment. The mean age of study-population was 35.68 ± 9.8 years, with female to male ratio of 11.5:1. The mean change in color score (1.68) was more by Group A, followed by Group C (1.4), followed by Group B (1.16). Similar results were noted by subjective improvement, VAS, and PGA. Adverse events were more in Group A, followed by Group C, followed by Group B. No patient showed permanent adverse events. TCA-peel showed superior results over Nd-YAG laser and glycolic-acid peel. TCA-peel being cost-effective with excellent acceptability should be considered a treatment modality.

A comparative urinary proteomic and metabolomic analysis between renal aa amyloidosis and membranous nephropathy with clinicopathologic correlations

Urinary omics has become a powerful tool for elucidating pathophysiology of glomerular diseases. However, no urinary omics analysis has been performed yet on renal AA amyloidosis. Here, we performed a comparative urine proteomic and metabolomic analysis between recently diagnosed renal AA amyloidosis (AA) and membranous nephropathy (MN) patients. Urine samples of 22 (8 AA, 8 MN and 6 healthy control) patients were analyzed with nLC-MS/MS and GC/MS for proteomic and metabolomic studies, respectively. Pathological specimens were scored for glomerulosclerosis and tubulointerstitial fibrosis grades. Functional enrichment analysis between AA and control groups showed enrichment in cell adhesion related sub-domains. Uromodulin (UMOD) was lower, whereas ribonuclease 1 (RNase1) and α-1-microglobulin/bikunin precursor (AMBP) were higher in AA compared to MN group. Correlations were demonstrated between UMOD-proteinuria (r = −0.48, p = 0.03) and AMBP-eGFR (r = −0.69, p = 0.003) variables. Metabolomic analysis showed myo-inositol and urate were higher in AA compared to MN group. A positive correlation was detected between RNase1 and urate independent of eGFR values (r = 0.63, p = 0.01). Enrichment in cell adhesion related domains suggested a possible increased urinary shear stress due to amyloid fibrils. UMOD, AMBP and myo-inositol were related with tubulointerstitial damage, whereas RNase1 and urate were believed to be related with systemic inflammation in AA amyloidosis. SignificanceUrinary omics studies have become a standard tool for biomarker studies. However, no urinary omics analysis has been performed yet on renal AA amyloidosis. Here, we performed a comparative urinary omics analysis between recently diagnosed renal AA amyloidosis (AA), membranous nephropathy (MN) patients and healthy controls. Pathological specimens were scored with glomerulosclerosis (G) and tubulointerstitial fibrosis (IF) grades to consolidate the results of the omics studies and correlation analyzes. Functional enrichment analysis showed enrichment in cell adhesion related sub-domains due to downregulation of cadherins; which could be related with increased urinary shear stress due to amyloid deposition and disruption of tissue micro-architecture. In comparative proteomic analyzes UMOD was lower, whereas RNase1 and AMBP were higher in AA compared to MN group. Whereas in metabolomic analyzes; myo-inositol, urate and maltose were higher in AA compared to MN group. Correlations were demonstrated between UMOD-proteinuria (r = −0.48, p = 0.03), AMBP-eGFR (r = −0.69, p = 0.003) and between RNase1-Urate independent of eGFR values (r = 0.63, p = 0.01). This study is the first comprehensive urinary omics analysis focusing on renal AA Amyloidosis to the best of our knowledge. Based on physiologic roles and clinicopathologic correlations of the molecules; UMOD, AMBP and myo-inositol were related with tubulointerstitial damage, whereas RNase1 and urate were believed to be increased with systemic inflammation and endothelial damage in AA amyloidosis.

An ultra performance liquid chromatography method for transthyretin variants screening and heart failure assisting diagnosis

BackgroundTransthyretin (TTR) gene mutations are associated with hereditary amyloidosis (ATTR) caused by mutant TTR protein dissociation, misfolding, aggregation, and insoluble fibrils deposition. Herein, we reported a chromatographic approach for quantification and identification of TTR tetramer in human blood serum by ultra performance liquid chromatography (UPLC). MethodsTTR proteins and serum were incubated with a fluorescent TTR tetramer sensor (A2). The A2 sensor specifically reacted with tetrameric TTR and released stoichiometric fluorescence that was detected by fluorescence detector coupled to UPLC. The external standard was used for quantification, the chromatographic peak parameters were used to identification certain mutation types. ResultsUPLC correctly distinguished 18 types of mutant TTR proteins from wild type. The results were consistent with follow-up analysis of two ATTR patients’ blood serum samples. In addition, the tetrameric TTR of 30 heart failure (HF) patients showed strongly correlation (r = −0.63, p < 0.00) with NT-proBNP, a HF clinical biomarker. ConclusionsUPLC method has sufficient accuracy to eliminate the necessity of sequencing for certain types of TTR mutations and allows for facile initial screening of ATTR amyloidosis patients, carriers, and healthy individuals for time-saving and economical purposes. TTR tetramer may serve as a diagnostic biomarker to evaluate the risk of HF diseases.

Prevalence of transthyretin amyloidosis in patients undergoing carpal tunnel surgery: a prospective cohort study and risk factor analysis.

Transthyretin amyloidosis is a frequent cause of heart failure, resulting from an accumulation of abnormal proteins in the myocardium. Recent research has highlighted the importance of early diagnosis to enhance the effectiveness of specific treatments. Extra-cardiac symptoms may precede several years before cardiac complications, with carpal tunnel syndrome often considered a red flag. The aim of this prospective, observational cohort study was to determine the incidence rate of positive synovial biopsies for transthyretin amyloidosis in patients aged 60-80 years undergoing carpal tunnel decompression, and to identify risk factors. The diagnosis of transthyretin amyloidosis was confirmed through the analysis of synovial tissue biopsies using Congo Red and immunohistochemical staining. The study included 254 patients, with an 18.5% prevalence of transthyretin amyloidosis. Risk factors for positive test results were identified as male sex, trigger finger, hearing disorders and valve disease. A predictive analysis using logistic regression yielded a probability model for individuals belonging to the positive group.Level of evidence III.

Prevention of thrombotic complications in patients with AL amyloidosis

Background. The problem of hemostasis system pathology in patients with AL amyloidosis (AL-A) is of great practical importance. Currently, there are no recommendations concerning indications and methods of prevention of thrombotic complications.Aim. To study the main parameters of blood coagulation system in patients with AL amyloidosis, to determine the indications for anticoagulant therapy, to evaluate the efficacy and safety of apixaban prophylactic use during antitumor therapy.Materials and methods. A prospective single-center study included 65 patients with newly diagnosed systemic AL amyloidosis. The median age was 58 (34–74) years. Induction therapy according to the program BorCyDex (bortezomib, cyclophosphamide, dexamethasone) was given to 59 (90 %) patients, of which 5 patients received the combination of BorCyDex with a monoclonal antibody to CD38 – daratumumab. The remaining 6 (10 %) patients were treated with melphalan. Patients with laboratory signs of hypercoagulability or thrombotic complications were treated with apixaban in therapeutic or prophylactic dose. Indications for apixaban therapy in therapeutic dose (10 mg/day): atrial fibrillation, arterial thrombosis or pulmonary embolism less than 1 year ago. Indications for apixaban therapy in prophylactic dose (5 mg/day) were considered the presence of one or more factors: hypoalbuminemia less than 20 g/L; increase in D-dimer level more than 500 ng/mL without instrumentally verified arterial or venous thrombosis; increase in D-dimer level more than 500 ng/mL within 3 months after resolved episode of thrombosis; increase in fibrinogen level more than 4 g/L; increase in FVIII activity more than 150 %. When two or more factors were present, an antiplatelet agent (acetylsacylicylic acid) was added to apixaban therapy. The follow-up period was 4–9 months (median 6 months).Results. Before the start of antitumor therapy, thrombotic complications were diagnosed in 15 (23 %), bleeding – in 3 (5 %) patients. Hemostasis study revealed an increase in one or more laboratory parameters reflecting hypercoagulability in 92 % of patients. Increase in fibrinogen level was found in 70 %, D-dimer – in 72 %, FVIII activity – in 92 % of patients. 3 (5 %) patients received a therapeutic dose of apixaban, 58 (89 %) patients ‒ a prophylactic dose. Therapy with apixaban and antiplatelet agent was performed in 10 (15 %) patients. During the follow-up 3 patients developed complications related to hemostasis system disorders: 1 (2 %) patient had thrombosis (ischemic stroke), 2 (3 %) – gastrointestinal bleeding of mild severity. All these patients received a prophylactic dose of apixaban due to the presence of 1 thrombosis risk factor: an increase in FVIII activity of more than 150 %.Conclusion. Clinical signs of hemostasis system pathology were observed in 28 % of AL amyloidosis patients, and laboratory signs of hypercoagulability were detected in 92 %. Our developed indications for thrombosis prophylaxis in AL amyloidosis were effective. The issue of FVIII activity increase as the only indication for anticoagulant therapy in AL amyloidosis patients requires further research.

Clinical Outcomes of Percutaneous Coronary Intervention in Amyloidosis, Sarcoidosis, and Hemochromatosis

BackgroundInfiltrative diseases (IDs), including amyloidosis, sarcoidosis, and hemochromatosis, are characterized by abnormal cellular infiltration in multiple organs, including the heart. The prognosis of percutaneous coronary intervention (PCI) patients with underlying IDs has not been well-studied. We evaluated the prevalence of IDs in patients undergoing PCI and their association with post-PCI outcomes. MethodsThe National Inpatient Sample (NIS) 2016-2020 database was used to identify PCI patients with ICD-10 codes for a retrospective analysis. PCI patients were then divided into those with and without underlying IDs, which included amyloidosis, sarcoidosis, and hemochromatosis. Multivariable logistic regression was performed for composite post-PCI outcomes analyses. ResultsAmong 2,360,860 patients admitted to undergo PCI, 7855 patients had underlying IDs. The highest prevalence was observed for sarcoidosis (0.2%) followed by hemochromatosis (0.07%) and amyloidosis (0.04%). Underlying amyloidosis was associated with worse composite post-PCI outcomes (odds ratio [OR], 1.6; 95% CI, 1.1-2.44; P = .02), including higher in-hospital mortality (OR, 1.9; 95% CI, 1.1-3.4; P = .04), higher risk of intra/post-PCI stroke (OR, 4.0; 95% CI, 1.1-16.0; P = .04), but not major bleeding (OR, 2.2; 95% CI, 0.97-5.03; P = .058). In contrast, underlying sarcoidosis (OR, 1.1; 95% CI, 0.87-1.41; P = .4), and hemochromatosis (OR, 1.18; 95% CI, 0.77-1.8; P = .44) were not associated with composite post-PCI outcomes. Amyloidosis patients undergoing PCI also had higher hospitalization charges ($212,123 vs $141,137; P = .03) and longer length of stay (8.2 vs 3.9 days; P < .001). ConclusionsUnderlying amyloidosis was associated with worse post-PCI outcomes including higher in-hospital mortality, intra/post-PCI stroke, and socioeconomic burden. A multidisciplinary approach and future studies are needed to investigate the screening and treatment strategies in these patients.

Generation of two induced pluripotent stem cell lines from hereditary amyloidosis patients with polyneuropathy carrying heterozygous transthyretin (TTR) mutation

Hereditary transthyretin amyloidosis with polyneuropathy (ATTR-PN) results from specific TTR gene mutations. In this study, we generated two induced pluripotent stem cell (iPSC) lines derived from ATTR-PN patients with heterozygous TTR gene mutations (Ala97Ser and Phe64Leu). These iPSC lines exhibited normal morphology, karyotype, high pluripotency marker expression, and differentiation into cells representing all germ layers. The generation of these iPSC lines serve as a valuable tool for investigating the mechanisms of ATTR-PN across various cell types and facilitating patient-specific in vitro amyloidosis modeling.

Light Chain Amyloidosis Plasma Cells Show Specific Chromatin Accessibility and Transcriptome

Immunoglobin light chain amyloidosis (AL) is a monoclonal gammopathy characterized by the accumulation of malignant plasma cells (PC) in the bone marrow. These PCs secrete misfolded immunoglobulin light chains fibrils, which deposit in various organs, leading to organ dysfunction. Unlike other monoclonal gammopathies such as Multiple Myeloma, both its rarity and the lower BM PC burden has limited the deep study of the tumor population. The aim of this study was to analyze the transcriptome and epigenome of the PC from patients with AL amyloidosis to identify the role of chromatin modifications in the pathogenesis of the disease. Highly purified clonal PCs were obtained from bone marrow aspirates samples of 58 AL amyloidosis patients at diagnosis, 19 monoclonal gammopathy of undetermined significance (MGUS), 149 MM and 17 healthy donors. RNA was obtained from PCs and Illumina Stranded Total RNA-seq protocol was performed according to manufacturer's specifications. Accessible chromatin mapping was performed using FAST-ATACseq (Corces et al, 2016) with minor modifications. The data obtained were aligned with the GRCh38 version of the human genome and custom pipelines were used for computational analyses. Expression of immunoglobulin genes was removed for RNAseq analysis. Unsupervised principal component analysis of the RNAseq and ATACseq data showed a clear distinction between PCs from AL patients, MM and HD. To obtain a reliable measure of the magnitude of epigenomic and transcriptome changes in AL, we compared the RNAseq and ATACseq data of AL with MM or HD. The RNAseq analysis showed some clear transcriptional programs (TPs) related to AL and different from MM and HD (Figure 1): TP1 showed 89 genes upregulated and associated with positive regulation of protein kinases and TP2 showed 274 genes downregulated and correlated with immunoregulatory interactions and mitotic regulation. On the other hand, TP3 included 560 downregulated genes associated with glutamate pathway and glycosylation of proteins and TP4 revealed 362 upregulated genes linked with B cell activation. Both patterns were identified in AL patients and HD in comparison with MM patients. Regarding chromatin accessibility, we detected a similar number of ATAC peaks between the AL and MGUS samples and with a significant difference compared to the MM samples (p=0.00014), suggesting that AL and PCs from MGUS have a lower chromatin accessibility (Figure 2). These results provide evidence that the biological perturbations in the chromatin accessibility and transcriptome of PCs from AL patients are highly specific. Although the results depicted in Figure 1 demonstrate that AL patients clustered together by relatively homogenous chromatin accessibility and transcriptome, compared with MM patients, we further investigated whether there were any discernible differences among AL patients themselves. To address this, we conducted an analysis of chromatin accessibility and transcriptome in relation to various factors, including age, gender, organ affected, light chain isotype, percentage of tumoral PCs, presence of t(11,14) or amp1q. Remarkably, we identified differences in the transcriptome between AL patients with and without t(11;14), identifying, 46 upregulated genes linked with T cell and lymphocyte apoptosis and inflammatory cytokines production and 257 downregulated genes linked with FGFR family ligand binding and activation and protein ubiquitination and phosphorylation, in t(11,14) positive AL patients. These results suggest that t(11;14) may exert a significant modulation on the transcriptome of PCs of AL patients. Finally, scRNAseq was performed to address the heterogeneity of PCs. Preliminary analysis has shown a remarkable homogeneity in malignant PCs from AL patients with very limited transcriptional differences between PCs clusters. In summary, in this study we have characterized the PCs of AL patients revealing a homogeneous and specific chromatin accessibility and transcriptome that could contribute to explain the differences between AL and other gammopathies, such as MM. In addition, the identification of these epigenetic and transcriptomic alterations in AL will allow us to better understand the aberrant biology driving this disease, such as those AL with t(11;14). Moreover, these findings open new avenues for the development of innovative therapeutic strategies to improve the outcomes for AL patients.

Early Development and Pre-Clinical Evaluation of a Fluorine-18 Labeled Peptide p5+14 for PET/CT Imaging of Cardiac Amyloidosis

Background:Systemic amyloidosis is a rare protein misfolding disorder, where patients can present with varied symptoms due to the diverse organ involvement. This is particularly true of patients with light chain associated (AL) amyloidosis, which makes early and accurate diagnosis challenging. Currently there are no FDA-approved methods that allow visualization of amyloidosis in patients. Nuclear imaging is a promising method for early detection of amyloid. We have developed a novel amyloid-reactive peptide, designated p5+14, capable of binding AL, as well as other types of amyloid, via multivalent electrostatic interactions. Peptide p5+14 has been successfully radiolabeled with radioiodine and technetium-99m and evaluated clinically, labeled with iodine-124, in a PET/CT imaging study of patients with amyloidosis (NCT03678259). While there are numerous advantages to using I-124 as the radionuclide for amyloid imaging, fluorine is a viable alternative for detecting cardiac amyloidosis. Fluorine-18 has a shorter half-life (108 min as compared to 4.2 days) thus reducing the internal radiation dose to patients. Moreover, F-18 is the most common nuclide used in PET imaging. We have previously generated a 18F-labeled variant of p5+14; however, the reaction was inefficient and not translatable. Here we present a novel development strategy for generating 18F labeled p5+14 using a commercially available precursor that can bind AL amyloid and perform initial characterization of the reagent in a murine model of inflammation-associated systemic AA amyloidosis. Methods: Isotopic exchange chemistry using a silicon-fluoride-acceptor (SiFA) method was used to label peptide p5+14 with F-18. The peptide precursor was purchased from Almac Life Sciences (Penicuik, UK). 18F was purchased from PetNet (Siemens Healthineers, Knoxville, TN) and prepared for reaction according to standard methods. After drying, F-18 (1000 - 1900 MBq ) was dissolved in anhydrous acetonitrile and the pH neutralized before the addition of peptide precursor. Radiolabeling was performed at room temperature for 5 min. After standard purification of the product, radiochemical purity studies demonstrated that it was stable, with no significant loss of F-18 for at least 5 hours. Radiofluorinated p5+14 was assessed in bioactivity “pulldown” assays to ensure binding to synthetic AL amyloid-like fibrils and human AL amyloid extracts. The radiolabeled peptide was also diluted in PBS and injected IV in the lateral tail vein of mice with severe systemic AA amyloidosis. After 1 h, mice were euthanized small animal PET/CT imaging performed and tissue biodistribution measurements were conducted using an automated Wizard 3 gamma counter (1480 Wallac Gamma Counter, Perkin-Elmer). Results: Using optimized synthesis conditions, the non-decay corrected radiochemical yield was 55±4.5%. Radiochemical purity was 99±1% at end of synthesis. Peptide purity was shown to be 93.7±4.9% by assessed using HPLC. Radiochemical stability was similarly evaluated using an HLPC method and remained &amp;gt;97.5% radiochemical purity at 5 hours after synthesis. The binding of 18F-p5+14 to synthetic AL amyloid like fibrils composed of a l6 variable domain was 96.2%, mimicking data using the radioiodinated peptide, and 87.2% to human AL amyloid extracts. Background binding to control beads was 17.4%. In mice, accumulation of 18F-peptide in the liver and spleen, the organs with most AA amyloid deposits in this mouse model, was readily evident in PET images taken 1 h post injection. There was also evidence of hepatic clearance of the peptide, manifest as a prominent gall bladder in the images. There was no accumulation of F-18 in bone, indicating positive in vivo stability. Imaging of amyloid-free wild type mice showed rapid clearance with radioactivity in the urinary bladder, gall bladder and gastrointestinal tract with little or no hepatosplenic radiotracer retention. Conclusion: Radiofluorination of peptides, such as p5+14, has been made more efficient through the use of novel precursors amenable to isotopic exchange. 18F-peptide binds amyloid effectively and may serve as a next generation radiotracer for the detection of cardiac amyloid by PET/CT imaging. Acknowledgments: EW is a doctoral student in the Comparative and Experimental Medicine Program. This study was supported by the Amyloidosis and Cancer Theranostics Program and the UTGSM.