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.

AA amyloidosis without systemic inflammation: when clinical evidence validates predictions of experimental medicine.

Amyloid A (AA) amyloidosis is a well-known consequence of chronic inflammatory diseases in which elevated plasma concentrations of serum amyloid A result in amyloid aggregation and organ damage. In this issue, Sikora et al. report, for the first time, an inherited form of AA amyloidosis occurring in the absence of systemic inflammation. This finding may provide novel insights into the pathogenesis of AA amyloidosis, allowing researchers to further dissect the role of inflammation from that of serum amyloid A.

Pharmacodynamic evaluation and safety assessment of treatment with antibodies to serum amyloid P component in patients with cardiac amyloidosis: an open-label Phase 2 study and an adjunctive immuno-PET imaging study.

BACKGROUND: In a Phase I study treatment with the serum amyloid P component (SAP) depleter miridesap followed by monoclonal antibody to SAP (dezamizumab) showed removal of amyloid from liver, spleen and kidney in patients with systemic amyloidosis. We report results from a Phase 2 study and concurrent immuno-positron emission tomography (PET) study assessing efficacy, pharmacodynamics, pharmacokinetics, safety and cardiac uptake (of dezamizumab) following the same intervention in patients with cardiac amyloidosis. METHODS: Both were uncontrolled open-label studies. After SAP depletion with miridesap, patients received ≤ 6 monthly doses of dezamizumab in the Phase 2 trial (n = 7), ≤ 2 doses of non-radiolabelled dezamizumab plus [89Zr]Zr-dezamizumab (total mass dose of 80 mg at session 1 and 500 mg at session 2) in the immuno-PET study (n = 2). Primary endpoints of the Phase 2 study were changed from baseline to follow-up (at 8 weeks) in left ventricular mass (LVM) by cardiac magnetic resonance imaging and safety. Primary endpoint of the immuno-PET study was [89Zr]Zr-dezamizumab cardiac uptake assessed via PET. RESULTS: Dezamizumab produced no appreciable or consistent reduction in LVM nor improvement in cardiac function in the Phase 2 study. In the immuno-PET study, measurable cardiac uptake of [89Zr]Zr-dezamizumab, although seen in both patients, was moderate to low. Uptake was notably lower in the patient with higher LVM. Treatment-associated rash with cutaneous small-vessel vasculitis was observed in both studies. Abdominal large-vessel vasculitis after initial dezamizumab dosing (300 mg) occurred in the first patient with immunoglobulin light chain amyloidosis enrolled in the Phase 2 study. Symptom resolution was nearly complete within 24 h of intravenous methylprednisolone and dezamizumab discontinuation; abdominal computed tomography imaging showed vasculitis resolution by 8 weeks. CONCLUSIONS: Unlike previous observations of visceral amyloid reduction, there was no appreciable evidence of amyloid removal in patients with cardiac amyloidosis in this Phase 2 trial, potentially related to limited cardiac uptake of dezamizumab as demonstrated in the immuno-PET study. The benefit-risk assessment for dezamizumab in cardiac amyloidosis was considered unfavourable after the incidence of large-vessel vasculitis and development for this indication was terminated. Trial registration NCT03044353 (2 February 2017) and NCT03417830 (25 January 2018).

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.

Amyloid storm: acute kidney injury and massive proteinuria, rapidly progressing to end-stage kidney disease in AA amyloidosis of familial Mediterranean fever.

OBJECTIVE: Amyloid A nephropathy of FMF usually progresses over many years to end-stage renal disease (ESRD). We aim to describe an acute condition, termed here 'amyloid storm', typically manifesting with a rapid (≤2 weeks) increase in serum creatinine and urine protein, that has never been characterized in FMF amyloidosis. METHODS: This retrospective analysis features amyloid storm by comparing between FMF amyloidosis patients who have experienced an episode of amyloid storm (study group) and matched patients who have not (control group). The primary outcome was ESRD or death within 1 year from study entry. Featured data were retrieved from hospital files. RESULTS: The study and control groups, each comprising 20 patients, shared most baseline characteristics. However, they differed on the time from FMF onset to reaching serum creatinine of 1.2 mg/dl [26.5 years (s.d. 15.15) vs 41.55 (10.98), P = 0.001] and the time from the onset of proteinuria to study entry [8.8 years (s.d. 6.83) vs 15.75 (13.05), P = 0.04], culminating in younger age at study entry [39.95 years (s.d. 16.81) vs 48.9 (9.98), respectively, P = 0.05] and suggesting an accelerated progression of kidney disease in the study group. Within 1 year from study entry, 16 patients in the study and 3 in the control groups reached the primary endpoint (P = 0.000). The major triggers of amyloid storm were infections, occurring in 17 of 20 patients. CONCLUSION: Amyloid storm is a complication of FMF amyloidosis, induced by infection and associated with poor prognosis and death.

Differential expression of MAP3K7 and TROPONIN C proteins and related perturbations in renal amyloidosis.

OBJECTIVES: Renal amyloidosis (RA) is a rare protein misfolding disorder that prompts progressive renal insufficiency. This study aimed to decipher proteomic changes in human sera to understand the pathophysiology and molecular mechanisms underlying the disease development, hence assisting in the diagnosis of RA. METHODS: Serum proteomic analysis was performed using a gel-based approach followed by MALDI-TOF MS. RA patients with age and sex matched healthy volunteers were recruited from Max Super Speciality Hospital, New Delhi, India. RESULTS: Proteome profiles of serum revealed eight differentially expressed proteins namely, Zinc finger protein 624, Protein FAM183A, Calcium-binding mitochondrial carrier protein Scamc-3, V-type proton ATPase 116 kDa subunit A isoforms 2, Protein TXNRD3NB, ATP - dependent RNA helicase, Troponin C and Mitogen-activated protein kinase kinase kinase 7. These proteins were reported first time in RA. The increased levels of MAP3K7 and TROPONIN C were validated by bio-layer interferometry and their diagnostic accuracy was evaluated by ROC curve analysis. The differentially expressed proteins were predominantly associated with vesicular trafficking, transcriptional regulation, metabolic processes, apoptotic process and mitochondrial metabolism. CONCLUSION: The results indicate that these proteomic signatures may be considered as potential molecular targets for RA diagnostics and therapeutics subject to validation on large sample size. Abbreviations: AßP= Amyloid-beta protein, Aß=Amyloid-beta, AL= Light chain amyloidosis, AA= Amyloid A, ALECT2= LECT2 amyloidosis, APS= Ammonium persulfate CKD= Chronic Kidney Diseases, EBRT= external beam radiation therapy, ESRD= End-Stage Kidney Disease, Glis2= Gli-similar 2, JNK= c-Jun NH 2-terminal kinase, MAPK= Mitogen-Activated Protein Kinase, MM=Multiple Myeloma, PHD= Prolyl hydroxylase, RA = Renal Amyloidosis, SAA= Serum Amyloid A, SD= Standard Deviation, Sepp= Selenoprotein, SCC= Squamous cell carcinoma, SDS= Sodium dodecyl sulfate, TEMED = tetramethyl ethylenediamine, TGF-Beta-1=Transforming growth factor- Beta-1, Trx = Thioredoxin, TrxR= Thioredoxin reductase.

Structural Basis for Vital Function and Malfunction of Serum Amyloid A: an Acute-Phase Protein that Wears Hydrophobicity on Its Sleeve.

PURPOSE OF REVIEW: This review addresses normal and pathologic functions of serum amyloid A (SAA), an enigmatic biomarker of inflammation and protein precursor of AA amyloidosis, a life-threatening complication of chronic inflammation. SAA is a small, highly evolutionarily conserved acute-phase protein whose plasma levels increase up to one thousand-fold in inflammation, infection, or after trauma. The advantage of this dramatic but transient increase is unclear, and the complex role of SAA in immune response is intensely investigated. This review summarizes recent advances in our understanding of the structure-function relationship of this intrinsically disordered protein, outlines its newly emerging beneficial roles in lipid transport and inflammation control, and discusses factors that critically influence its misfolding in AA amyloidosis. RECENT FINDINGS: High-resolution structures of lipid-free SAA in crystals and fibrils have been determined by x-ray crystallography and electron cryo-microscopy. Low-resolution structural studies of SAA-lipid complexes, together with biochemical, cell-based, animal model, genetic, and clinical studies, have provided surprising new insights into a wide range of SAA functions. An emerging vital role of SAA is lipid encapsulation to remove cell membrane debris from sites of injury. The structural basis for this role has been proposed. The lysosomal origin of AA amyloidosis has solidified, and its molecular and cellular mechanisms have emerged. Recent studies have revealed molecular underpinnings for understanding complex functions of this Cambrian protein in lipid transport, immune response, and amyloid formation. These findings help guide the search for much-needed targeted therapies to block the protein deposition in AA amyloidosis.

Daratumumab yields rapid and deep hematologic responses in patients with heavily pretreated AL amyloidosis.

The majority of patients with immunoglobulin light chain amyloidosis (AL) fail to achieve a complete response (CR) to standard light chain suppressive chemotherapy, and almost all patients eventually experience hematologic relapse and progression of organ involvement. Additional well-tolerated treatment options are needed. We present our retrospective experience of 25 consecutive previously treated AL patients who received daratumumab, a CD38-directed monoclonal antibody approved for the treatment of multiple myeloma. Daratumumab was administered at 16 mg/kg weekly for 8 weeks, then every 2 weeks for 8 doses, and then every 4 weeks. Patients had received a median of 3 prior lines of therapy, with a previous hematologic CR in only 5 patients. The overall hematologic response rate to daratumumab was 76%, including CR in 36% and very good partial response in 24%. Median time to response was 1 month. Therapy was well tolerated, even among the 72% of patients with cardiac AL involvement. Grade 1-2 infusion reactions occurred in 15 patients, but no grade 3 or 4 reactions were observed. Daratumumab is a highly effective agent that produced rapid and deep hematologic responses without unexpected toxicity in our cohort of heavily pretreated AL patients.

Patients with light-chain amyloidosis and low free light-chain burden have distinct clinical features and outcome.

The validated criteria of hematologic response in light-chain (AL) amyloidosis are based on the measurement of circulating free light chains (FLCs). Patients with a difference between involved and uninvolved FLC (dFLC) <50 mg/L cannot be assessed for response and are excluded from clinical trials. We compared the clinical characteristics and outcome of 203 newly diagnosed patients with dFLC <50 mg/L (low dFLC) with 866 patients with measurable dFLC (high dFLC) evaluated between 2004 and 2015. Heart involvement was significantly less common and less advanced in the low-dFLC group (43% vs 83% and Mayo stage III 45% vs 15%, both P < .001), whereas renal involvement was more frequent (77% vs 63%, P < .001) and more severe (renal stage III 26% vs 18%, P = .001). Overall survival (OS) was significantly better in the low-dFLC group (median 117 vs 21 months, P < .001), whereas no difference was seen in renal survival (RS). Within each Mayo stage, patients with low dFLC had a longer survival. In the low-dFLC group, complete response was associated with a significant advantage in OS (median not reached vs 117 months, P = .005) and with a better RS. A reduction in dFLC after therapy of <10 mg/L was associated with a better OS and RS in patients with at least a dFLC >20 mg/L baseline. Nineteen percent of newly diagnosed patients with AL amyloidosis have low dFLC and had a better outcome. Hematologic response assessed with adapted criteria predicts OS and RS in these patients, who can thus be assessed for response and included in clinical trials with appropriate stratification.

AL amyloidosis patients with low amyloidogenic free light chain levels at first diagnosis have an excellent prognosis.

The difference between involved minus uninvolved serum free light chains (dFLC) has been established as an invaluable hematologic parameter in systemic amyloid light chain (AL) amyloidosis. However, patients with an initial dFLC level <50 mg/L are currently deemed not evaluable for response to therapy. Therefore, we aimed to characterize this subgroup of patients and to define novel hematologic response parameters. We retrospectively analyzed 783 AL patients newly diagnosed at our center between 2002 and 2016. Patients with a dFLC level <50 mg/L showed smaller bone marrow plasmacytosis compared to patients with a dFLC level ≥50 mg/L (7% vs 10%, P < .001), but no significant differences in all analyzed chromosomal aberrations. Cardiac involvement was less frequent (45% vs 80%, P < .001) and less severe (Mayo 2004 stage III: 18% vs 51%, P < .001), whereas kidney involvement was more prevalent (83% vs 53%, P < .001) and proteinuria was higher (7.3 g/L vs 5.0 g/L, P < .001). In multivariate analyses, a dFLC level <50 mg/L appeared to be an independent prognostic factor with respect to overall survival (hazard ratio [HR] = 0.50, P = .003) and renal survival (HR = 0.56, P = .020). Patients with a dFLC level <50 mg/L showed a higher proportion of complete hematologic response after first-line therapy compared to patients with a dFLC level ≥50 mg/L (39% vs 9%, P < .001). Receiver-operating characteristics analysis identified a low-dFLC partial response (dFLC <10 mg/L for patients with a dFLC between 20 and 50 mg/L), which predicted overall and renal survival already at 3 months after the start of therapy. Importantly, a parallel Italian study validated this new hematologic remission parameter. The outcome of prospective clinical trials might be adversely influenced by exclusion of the favorable clinical subgroup with an initial dFLC <50 mg/L. We propose the appreciation of dFLC in hematologic response assessment for all patients with a baseline dFLC >20 mg/L.

Detection of cardiac amyloidosis with 18F-Florbetaben-PET/CT in comparison to echocardiography, cardiac MRI and DPD-scintigraphy.

PURPOSE: Cardiac amyloidosis (CA) is a rare cause of heart failure with frequently delayed diagnosis, because specific early signs or symptoms are missing. Recently, direct amyloid imaging using positron emission tomography/computed tomography (PET/CT) has emerged. The aim of this study was to examine the performance of 18F-florbetaben-PET/CT in detection of CA, and compare it to echocardiography (echo), cardiac MRI (CMR) and scintigraphy. Additionally, the use of 18F-florbetaben-PET/CT for quantification of amyloid burden and monitoring of treatment response was assessed. METHODS: Twenty-two patients with proven (n = 5) or clinical suspicion (n = 17) of CA underwent 18F-florbetaben-PET/CT for diagnostic work-up. Qualitative and quantitative assessment including calculation of myocardial tracer retention (MTR) was performed, and compared to echo (n = 20), CMR (n = 16), scintigraphy (n = 16) and serologic biomarkers (NT-proBNP, cTnT, free light chains). In four patients, follow-up PET/CT was available (after treatment initiation, n = 3; surveillance, n = 1). RESULTS: PET demonstrated myocardial 18F-florbetaben retention consistent with CA in 14/22 patients. Suspicion of CA was subsequently dropped in all eight PET-negative patients. Amyloid subtypes showed characteristic retention patterns (AL > AA > ATTR; all p < 0.005). MTR correlated with morphologic and functional parameters, as measured by CMR and echo (all r| > 0.47|, all p < 0.05), but not with cardiac biomarkers. Changes in MTR from baseline to follow-up corresponded well to treatment response, as assessed by cardiac biomarkers and performance status. CONCLUSIONS: Imaging of cardiac amyloidosis (CA) with 18F-florbetaben-PET/CT is feasible and might be useful in differentiating CA subtypes.

Molecular mechanisms underlying uremic toxin-related systemic disorders in chronic kidney disease: focused on ß2-microglobulin-related amyloidosis and indoxyl sulfate-induced atherosclerosis-Oshima Award Address 2016.

Uremic toxins are linked to chronic kidney disease (CKD)-related systemic diseases. ß2-Microglobulin (ß2-m), a water-soluble, middle-sized molecule, is associated with mortality and dialysis-related amyloidosis (DRA). DRA occurs in long-term dialysis patients, with ß2-m amyloid deposited mainly in osteoarticular tissues. We investigated a model of ß2-m amyloid fibril extension at neutral pH in the presence of trifluoroethanol or sodium dodecyl sulfate. Using this model, some biological molecules, including glycosaminoglycans and lysophospholipids, were found to be chaperones for ß2-m amyloid fibril extension. Several protein-bound solutes, such as indoxyl sulfate (IS) and p-cresyl sulfate, are independent risk factors for cardiovascular disease in CKD patients, especially those undergoing dialysis. We investigated kidney injury-induced acceleration of atherosclerosis in association with macrophage phenotypic change to a proinflammatory state as well as increased IS deposition in lesions in an animal model. IS directly induced macrophage inflammation and impaired cholesterol efflux to high-density lipoprotein (HDL) in vitro. In addition, a clinical study showed that HDL isolated from CKD patients induced proinflammatory reactions and impaired cholesterol efflux to macrophages. These findings suggest that protein-bound solutes, including IS, will induce dysfunction of both macrophages and HDL in atherosclerotic lesions. To remove uremic toxins efficiently, we demonstrated the potential efficacy of oral charcoal adsorbent and hexadecyl-immobilized cellulose beads in hemodialysis patients. These findings suggest that uremic toxins induce various CKD-related systemic disorders, and further therapeutic strategies will be needed to reduce uremic toxins enough and improve life expectancy in CKD patients.

Assessment of Mean Platelet Volume in Patients with AA Amyloidosis and AA Amyloidosis Secondary to Familial Mediterranean Fever: A Retrospective Chart - Review Study.

BACKGROUND Amyloidosis is a protein-misfolding disease characterized by the deposition of aggregated proteins in the form of abnormal fibrils that disrupt tissue structure, ultimately causing disease. Amyloidosis is very frequent in untreated familial Mediterranean fever (FMF) patients and it is the most important feature that determines the prognosis of FMF disease. The mean platelet volume (MPV) in FMF has been previously studied. However, whether MPV level in FMF patients is lower or higher compared to healthy controls remains a topic of ongoing debate. In this study, we aimed to investigate MPV values and to assess the correlation between MPV and proteinuria in patients with AA amyloidosis and AA amyloidosis secondary to familial Mediterranean fever (AA-FMF) through a retrospective chart-review. MATERIAL AND METHODS This study was carried out on 27 patients with AA amyloidosis, 36 patients with AA amyloidosis secondary to FMF (a total of 63 patients with AA), and 29 healthy controls. There was no statistically significant difference between the AA patients and the control group (p=0.06) or between the AA-FMF group and the control group in terms of MPV values (p=0.12). RESULTS We found a statistically significant negative correlation between MPV and thrombocyte count in all groups (p<0.05 for all groups), but there was no correlation between MPV and proteinuria levels in AA patients (p=0.091). CONCLUSIONS While similar results also exist, these findings are contrary to the majority of previous studies. Therefore, further controlled clinical prospective trials are necessary to address this inconsistency.

Primary fatty amides in plasma associated with brain amyloid burden, hippocampal volume, and memory in the European Medical Information Framework for Alzheimer's Disease biomarker discovery cohort.

INTRODUCTION: A critical and as-yet unmet need in Alzheimer's disease (AD) is the discovery of peripheral small molecule biomarkers. Given that brain pathology precedes clinical symptom onset, we set out to test whether metabolites in blood associated with pathology as indexed by cerebrospinal fluid (CSF) AD biomarkers. METHODS: This study analyzed 593 plasma samples selected from the European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery study, of individuals who were cognitively healthy (n = 242), had mild cognitive impairment (n = 236), or had AD-type dementia (n = 115). Logistic regressions were carried out between plasma metabolites (n = 883) and CSF markers, magnetic resonance imaging, cognition, and clinical diagnosis. RESULTS: Eight metabolites were associated with amyloid ß and one with t-tau in CSF, these were primary fatty acid amides (PFAMs), lipokines, and amino acids. From these, PFAMs, glutamate, and aspartate also associated with hippocampal volume and memory. DISCUSSION: PFAMs have been found increased and associated with amyloid ß burden in CSF and clinical measures.

What is new in diagnosis and management of light chain amyloidosis?

Light chain (AL) amyloidosis is caused by a usually small plasma cell clone producing a misfolded light chain that deposits in tissues. Survival is mostly determined by the severity of heart involvement. Recent studies are clarifying the mechanisms of cardiac damage, pointing to a toxic effect of amyloidogenic light chains and offering new potential therapeutic targets. The diagnosis requires adequate technology, available at referral centers, for amyloid typing. Late diagnosis results in approximately 30% of patients presenting with advanced, irreversible organ involvement and dying in a few months despite modern treatments. The availability of accurate biomarkers of clonal and organ disease is reshaping the approach to patients with AL amyloidosis. Screening of early organ damage based on biomarkers can help identify patients with monoclonal gammopathy of undetermined significance who are developing AL amyloidosis before they become symptomatic. Staging systems and response assessment based on biomarkers facilitate the design and conduction of clinical trials, guide the therapeutic strategy, and allow the timely identification of refractory patients to be switched to rescue therapy. Treatment should be risk-adapted. Recent studies are linking specific characteristics of the plasma cell clone to response to different types of treatment, moving toward patient-tailored therapy. In addition, novel anti-amyloid treatments are being developed that might be combined with anti-plasma cell chemotherapy.

Clinical and prognostic significance of serum levels of von Willebrand factor and ADAMTS-13 antigens in AL amyloidosis.

Cardiac dysfunction determines prognosis in amyloid light-chain (AL) amyloidosis. The heart is the central organ of the vascular system in which endothelium function is critical for the circulatory homeostasis, but there are limited data on endothelial function in AL amyloidosis. von Willebrand factor (VWF) has been considered as a marker of endothelial activation and dysfunction, whereas a disintegrin and metalloproteinase with thrombospondin type-1 repeats 13 (ADAMTS-13) cleaves VWF multimers, but both have been associated with prognosis in cardiovascular disease. We measured the serum levels of VWF (VWF:Ag) and ADAMTS-13 antigens in 111 newly diagnosed patients with AL amyloidosis. The levels of VWF:Ag were significantly higher than in healthy controls; 76% of patients with AL had VWF:Ag levels higher than the upper levels of controls. There was no significant association of VWF:Ag levels with patterns of organ involvement, free light-chain levels, the levels of cardiac biomarkers, or renal dysfunction but correlated with low systolic blood pressure. VWF:Ag levels ≥230.0 U/dL were associated with higher probability of early death and poor survival independently of cardiac biomarkers and low systolic blood pressure (SBP). Moreover, among patients with Mayo stage III or stage IIIB (that is stage III with N-terminal pro-brain natriuretic peptide [NTproBNP] >8500 pg/mL) disease, VWF:Ag identified subgroups of patients with very poor outcome. Low ADAMTS-13 levels correlated with high levels of NTproBNP but had no independent prognostic significance. In conclusion, high VWF:Ag levels, probably representing endothelial dysfunction, are associated with prognosis in patients with AL amyloidosis, independently of other features of the disease or cardiac biomarkers.

Current and future circulating biomarkers for cardiac amyloidosis.

Cardiac amyloidosis (CA) comprises a heterogeneous group of medical conditions affecting the myocardium. It presents with proteinaceous infiltration with variable degrees of severity, prevalence and evolution. Despite this heterogeneity, erroneous protein folding is the common pathophysiologic process, yielding the formation of a single misfolded protein (monomer) that progressively evolves and ultimately forms amyloid fibers. Additionally, by seeding out from the organs of origin, intermediates called oligomers metastasize and restart the process. Such self-echoing behavior makes the secondary affected organs as important as the primary ones. Unfortunately, CA can be clinically challenging and only suggestive in a late stage of its natural history, leaving a narrow therapeutic time window available. In light of the evolutionary nature of amyloidosis, here, we propose a new classification of the currently used biomarkers based on time stages with different specificity and applicability across CA subtypes. Early markers (free light chains, serum amyloid A, ß2-microglobulin, osteopontin and osteoprotegerin) can be employed for disease detection. Intermediate markers [soluble suppression of tumorigenicity 2 (sST-2), midregional proadrenomedullin (MR-proADM), von Willebrand factor (vWF), hepatocyte growth factor (HGF), matrix metalloproteinases (MMPs) and tissue inhibitor metalloproteinases (TIMPs)] can provide information on the biological mechanisms of myocardial damage. As in heart failure, late-stage biomarkers (troponins and natriuretic peptides) can help clinicians with prognosis and therapeutic response evaluation in CA. Such findings have generated a remarkable foundation for our current knowledge on CA. Nevertheless, we envision a future class of biomarkers targeted at upstream events capable of detecting folding defects, which will ultimately expand the therapeutic window.

Renal-limited AL amyloidosis - a diagnostic and management dilemma.

BACKGROUND: Amyloidosis is a disorder caused by extracellular tissue deposition of insoluble fibrils which may result in a wide spectrum of symptoms depending upon their types, sites and amount of deposition. Amyloidosis can be divided into either systemic or localized disease. CASE PRESENTATION: We present a case of a middle-aged gentleman who presented with persistent nephrotic syndrome with worsening renal function. Repeated renal biopsies showed the presence of renal-limited AL amyloidosis. Systemic amyloidosis workup was unremarkable apart from a slightly raised band of IgG lambda level with no associated immunoparesis. The nephrotic syndrome and renal histology did not improve over a 3-year period despite being given two courses of chemotherapies. CONCLUSION: We hope that early recognition of this unusual localised presentation of renal- limited AL Amyloidosis and its poor response to conventional treatment can alert the nephrologist to the potential existence of this rare condition.

C-terminal sequence of amyloid-resistant type F apolipoprotein A-II inhibits amyloid fibril formation of apolipoprotein A-II in mice.

In murine senile amyloidosis, misfolded serum apolipoprotein (apo) A-II deposits as amyloid fibrils (AApoAII) in a process associated with aging. Mouse strains carrying type C apoA-II (APOA2C) protein exhibit a high incidence of severe systemic amyloidosis. Previously, we showed that N- and C-terminal sequences of apoA-II protein are critical for polymerization into amyloid fibrils in vitro. Here, we demonstrate that congenic mouse strains carrying type F apoA-II (APOA2F) protein, which contains four amino acid substitutions in the amyloidogenic regions of APOA2C, were absolutely resistant to amyloidosis, even after induction of amyloidosis by injection of AApoAII. In vitro fibril formation tests showed that N- and C-terminal APOA2F peptides did not polymerize into amyloid fibrils. Moreover, a C-terminal APOA2F peptide was a strong inhibitor of nucleation and extension of amyloid fibrils during polymerization. Importantly, after the induction of amyloidosis, we succeeded in suppressing amyloid deposition in senile amyloidosis-susceptible mice by treatment with the C-terminal APOA2F peptide. We suggest that the C-terminal APOA2F peptide might inhibit further extension of amyloid fibrils by blocking the active ends of nuclei (seeds). We present a previously unidentified model system for investigating inhibitory mechanisms against amyloidosis in vivo and in vitro and believe that this system will be useful for the development of novel therapies.

Human Central Nervous System (CNS) ApoE Isoforms Are Increased by Age, Differentially Altered by Amyloidosis, and Relative Amounts Reversed in the CNS Compared with Plasma.

The risk of Alzheimer's disease (AD) is highly dependent on apolipoprotein-E (apoE) genotype. The reasons for apoE isoform-selective risk are uncertain; however, both the amounts and structure of human apoE isoforms have been hypothesized to lead to amyloidosis increasing the risk for AD. To address the hypothesis that amounts of apoE isoforms are different in the human CNS, we developed a novel isoform-specific method to accurately quantify apoE isoforms in clinically relevant samples. The method utilizes an antibody-free enrichment step and isotope-labeled physiologically relevant lipoprotein particle standards produced by immortalized astrocytes. We applied this method to a cohort of well characterized clinical samples and observed the following findings. The apoE isoform amounts are not different in cerebrospinal fluid (CSF) from young normal controls, suggesting that the amount of apoE isoforms is not the reason for risk of amyloidosis prior to the onset of advanced age. We did, however, observe an age-related increase in both apoE isoforms. In contrast to normal aging, the presence of amyloid increased apoE3, whereas apoE4 was unchanged or decreased. Importantly, for heterozygotes, the apoE4/apoE3 isoform ratio was increased in the CNS, although the reverse was true in the periphery. Finally, CSF apoE levels, but not plasma apoE levels, correlated with CSF ß-amyloid levels. Collectively, these findings support the hypothesis that CNS and peripheral apoE are separate pools and differentially regulated. Furthermore, these results suggest that apoE mechanisms for the risk of amyloidosis and AD are related to an interaction between apoE, aging, and the amount of amyloid burden.