Type Of Systemic Amyloidosis Research Articles

18F-Florbetaben PET/CT for the Diagnosis and Subtyping of Cardiac Amyloidosis: A Case Series and Review of the Literature.

Cardiac amyloidosis (CA) is a type of systemic amyloidosis. Amyloid-targeting positron emission tomography (PET) has shown potential as an imaging method for CA. However, the optimal imaging protocol and role of 18F-florbetaben (FBB) PET in the diagnosis and subtyping of CA have yet to be determined. Patients with suspected CA who had positive or equivocal results of technetium-99m pyrophosphate (PYP) scintigraphy were enrolled for dynamic and late FBB PET imaging. In addition to visual assessment, a kinetic modeling-based approach including target-to-background ratio (TBR) and myocardial retention fraction (RF) of serial images reconstructed from a 20-min dynamic acquisition, and a late image at 110 min post-injection were performed. We compared FBB PET measures of four typical patients with light chain amyloidosis (AL), wild-type transthyretin amyloidosis (ATTRwt), variant transthyretin amyloidosis (ATTRv), and heart failure, respectively. We also reviewed the literature on the clinical use of amyloid PET in CA. Myocardial tracer retention was only found in the AL patient on the late images. TBR and RF were highest in the AL patient followed by the ATTRwt patient, and lowest in the ATTRv and non-CA patients. FBB PET has potential in the detection and non-invasive subtyping of CA, especially in subjects with equivocal PYP findings or monoclonal gammopathy.

A Case Report on Renal Amyloidosis

Amyloidosis involves the deposition of abnormal proteins in various tissue and result in progressive organ dysfunction, commonly affecting multiple organs. Two types of systemic amyloidosis are AA and AL, the former is associated with acute phase reaction and the later is composed of light chain immunoglobulin. This disease commonly affects the kidneys and is evidenced by massive proteinuria. A biopsy is the gold standard of diagnosis, with Congo Red staining revealing an apple green birefringence under polarized light microscope. We are presenting a 45 years old male who presented with rapid rising serum creatinine with history of multiple myeloma (non secretory). There was also history of spine tuberculosis.

Chemical design of radioiodinated probes with a metabolizable linkage for target-selective imaging of systemic amyloidosis

IntroductionSystemic amyloidosis is a rare disease caused by the deposition of amyloid fibrils in various organs. Amyloid-targeted radiopharmaceuticals have been developed and applied to diagnose systemic amyloidosis peripherally; however, high-contrast imaging has not been achieved because of the high background signals in normal organs. To overcome this problem, we designed an amyloid-targeted radioiodinated probe 1 with a metabolizable linkage (ester bond) to release of radiolabeled metabolites (m-iodohippuric acid) in normal organs that could be rapidly excreted in the urine. MethodsCompound 1 was synthesized by conjugating 2-(4-(methylamino)phenyl)benzo[d]thiazol-6-ol, an amyloid-targeting compound, with m-iodohippuric acid. [125I]1 was synthesized via iododestannylation using a tributyltin precursor. Mouse models of amyloid A (AA) amyloidosis, a type of systemic amyloidosis, were prepared by administering amyloid-enhancing factor to mice and used for in vitro autoradiography using organ sections and in vivo evaluation. Results[125I]1 was obtained with a radiochemical yield of 59% and radiochemical purity of over 95%. An in vitro autoradiographic study demonstrated that [125I]1 specifically binds to amyloid in the splenic tissue. Upon administration to normal mice, [125I]1 was distributed to organs throughout the body, followed by the rapid excretion of radioactivity in the urine as m-[125I]iodohippuric acid. Furthermore, ex vivo autoradiography showed that [125I]1 bound to the amyloid formed around the follicles in the spleens of AA amyloidosis model mice. ConclusionThese results suggest that the interposition of a metabolizable linkage between an amyloid-targeting moiety and a radiolabeled hippuric acid would be useful in the design of radiopharmaceuticals for high-contrast imaging of systemic amyloidosis.

POS-298 LESSONS FROM FOUR DECADES OF SYSTEMIC AMYLOIDOSIS WITH RENAL INVOLVEMENT

The past four decades have seen remarkable advances in amyloidosis recognition due to more accurate fibrils identification, genetic assessment and diagnostic imaging. Apart from ATTR amyloidosis, the epidemiology and outcomes of the most common subtypes of systemic amyloidosis in Portugal remain primarily unknown. Hence, we report the epidemiology of 40 years of amyloid nephropathy at a single Portuguese centre and characterise the clinical features and course in 111 patients with different types of systemic amyloidosis with renal involvement.

Development of a radioiodinated thioflavin-T-Congo-red hybrid probe for diagnosis of systemic amyloidosis

IntroductionSystemic amyloidosis is a group of diseases characterized by the deposition of amyloid protein in multiple organs throughout the body and causing their dysfunction. As amyloid deposition is observed at an early phase and is highly specific to systemic amyloidosis, noninvasive detection of amyloid is considered useful for the early diagnosis of systemic amyloidosis. In this study, we designed and synthesized a novel radiolabeled amyloid imaging probe, sodium (E)-4-amino-3-((4-(6-iodobenzothiazol-2-yl)phenyl)diazenyl)naphthalene-1-sulfonate (1), which combines two amyloid-binding compounds, thioflavin-T and Congo-red, and evaluated its effectiveness in diagnosing amyloidosis. MethodsA tributyltin precursor was synthesized through a 5-step reaction from 2-amino-6-bromobenzothiazole, and [125I]1 was synthesized by an iododestannylation reaction with a tributyltin precursor. Mouse models of amyloid A (AA) amyloidosis, a type of systemic amyloidosis, were prepared by intraperitoneal injection of amyloid-enhancing factor into mice. An in vitro autoradiographic study was performed using spleen sections from normal mice and AA amyloidosis mice. Furthermore, [125I]1 was intravenously injected into mice, and its distribution was evaluated. Finally, an ex vivo autoradiographic study was performed using AA amyloidosis mice. Results[125I]1 was obtained with a radiochemical yield of 66% and a radiochemical purity of over 95%. In vitro autoradiography revealed specific binding of [125I]1 to thioflavin-S-stained regions in the spleen. Normal mice showed relatively rapid clearance of [125I]1 from the organs, whereas radioactivity was retained in the spleen, where amyloid deposition was observed in model mice. Furthermore, ex vivo autoradiography showed a heterogeneous distribution of [125I]1, which was co-localized with thioflavin-S-stained regions in the spleen of model mice. ConclusionThese results indicate the potential of radioiodinated 1 as a nuclear imaging probe for diagnosing AA amyloidosis.

Methods to study the structure of misfolded protein states in systemic amyloidosis.

Systemic amyloidosis is defined as a protein misfolding disease in which the amyloid is not necessarily deposited within the same organ that produces the fibril precursor protein. There are different types of systemic amyloidosis, depending on the protein constructing the fibrils. This review will focus on recent advances made in the understanding of the structural basis of three major forms of systemic amyloidosis: systemic AA, AL and ATTR amyloidosis. The three diseases arise from the misfolding of serum amyloid A protein, immunoglobulin light chains or transthyretin. The presented advances in understanding were enabled by recent progress in the methodology available to study amyloid structures and protein misfolding, in particular concerning cryo-electron microscopy (cryo-EM) and nuclear magnetic resonance (NMR) spectroscopy. An important observation made with these techniques is that the structures of previously described in vitro formed amyloid fibrils did not correlate with the structures of amyloid fibrils extracted from diseased tissue, and that in vitro fibrils were typically more protease sensitive. It is thus possible that ex vivo fibrils were selected in vivo by their proteolytic stability.

The Clinical Impact of Proteomics in Amyloid Typing

The Clinical Impact of Proteomics in Amyloid Typing

Nuclear Imaging for Cardiac Amyloidosis: Bone Scan, SPECT/CT, and Amyloid-Targeting PET.

Cardiac amyloidosis (CA) is a type of systemic amyloidosis, in which abnormal amyloid fibril is deposited in extracellular space of myocardium. Most common subtypes of CA are amyloidosis of immunoglobulin light chain (AL) and amyloidosis of transthyretin (ATTR). With increase in incidence of CA and development of new drugs, the needs of early and accurate diagnosis of CA are increasing. In CA, bone scan and SPECT/CT have long been used for diagnosis. Currently, bone scan is included in almost all practice guidelines as one of key diagnostic examinations for ATTR CA. In some specific scenarios, bone scan can be used as even a substitute for endomyocardial biopsy. Recently, amyloid-targeting PET that is used for Alzheimer dementia has also been attempted as an imaging method for CA. Although the study results are still insufficient, amyloid-targeting has shown promising potential as an imaging method for CA, particularly in AL. Here, imaging method and clinical application and implication of bone scan, SPECT/CT, and amyloid-targeting PET/CT in CA are reviewed.

Should the Reporting of Bone Marrow Positivity for Amyloid Be Revised? A Critical Assessment Based On 66 Biopsies From a Single Institution.

Amyloidoses are rare but heterogeneous disorders for which diagnosis is contingent upon the detection of deposits by Congo red stain and amyloid protein typing determines the treatment options. To address the reporting of bone marrow (BM) involvement by amyloid in relation to the spatial distribution of deposits and to explore whether the location of deposits may have clinical relevance. We examined 66 BM biopsies positive for amyloid with regard to the location and type of amyloid, the percentage and clonality of plasma cells, other organ involvement, and relevant clinical information. In 21 cases, amyloid deposits involved BM stroma, whereas 45 cases were nonstromal. All cases of stromal involvement were typed as AL amyloidosis (or presumed AL), whereas nonstromal involvement was associated with at least 3 types of amyloidosis: AL, ATTR, and AA. The initial diagnosis of amyloidosis was made in a BM specimen in 21 of 66 cases (31.8%). Plasma cells ranged from 1% to 80% (mean, 13.4%; median, 8%; <10% in 44 of 66 specimens [66.6%]) and were monoclonal in 58 of 66 cases (87.8%), and in 54 of 66 cases (81.8%) amyloid deposits were documented in at least one other organ. This study demonstrates that there is significant heterogeneity in the spatial distribution of amyloid in BM biopsy specimens with medullary, extramedullary, purely vascular, or combined involvement. Whereas stromal deposits were associated exclusively with AL, nonstromal and purely vascular deposits were seen in at least 3 types of systemic amyloidosis (AL, AA, and ATTR). We discuss the reporting of BM biopsy tissue positivity for amyloid deposits.

Typing of hereditary renal amyloidosis presenting with isolated glomerular amyloid deposition

BackgroundThe commonly used methods for amyloid typing include immunofluorescence or immunohistochemistry (IHC), which sometimes may come with diagnostic pitfalls. Mass spectrometry (MS)-based proteomics has been recognized as a reliable technique in amyloid typing.Case presentationWe reported two middle-aged patients who presented with proteinuria, hypertension and normal renal function, and both had a family history of renal diseases. The renal biopsies of both patients revealed renal amyloidosis with the similar pattern by massive exclusively glomerular amyloid deposition. The IHC was performed by using a panel of antibodies against the common types of systemic amyloidosis, and demonstrated co-deposition of fibrinogen Aα chain and apolipoprotein A-I in the glomerular amyloid deposits of each patient. Then the MS on amyloid deposits captured by laser microdissection (LMD/MS) and genetic study of gene mutations were investigated. The large spectra corresponding to ApoA-I in case 1, and fibrinogen Aα chain in case 2 were identified by LMD/MS respectively. Further analysis of genomic DNA mutations demonstrated a heterozygous mutation of p. Trp74Arg in ApoA-I in case 1, and a heterozygous mutation of p. Arg547GlyfsTer21 in fibrinogen Aα chain in case 2.ConclusionsThe current study revealed that IHC was not reliable for accurate amyloid typing, and that MS-based proteomics and genetic analysis were essential for typing of hereditary amyloidosis.

The complementary role of histology and proteomics for diagnosis and typing of systemic amyloidosis.

The tissue diagnosis of amyloidosis and confirmation of fibril protein type, which are crucial for clinical management, have traditionally relied on Congo red (CR) staining followed by immunohistochemistry (IHC) using fibril protein specific antibodies. However, amyloid IHC is qualitative, non‐standardised, requires operator expertise, and not infrequently fails to produce definitive results. More recently, laser dissection mass spectrometry (LDMS) has been developed as an alternative method to characterise amyloid in tissue sections. We sought to compare these techniques in a real world setting. During 2017, we performed LDMS on 640 formalin‐fixed biopsies containing amyloid (CR+ve) comprising all 320 cases that could not be typed by IHC (IHC−ve) and 320 randomly selected CR+ve samples that had been typed (IHC+ve). In addition, we studied 60 biopsies from patients in whom there was a strong suspicion of amyloidosis, but in whom histology was non‐diagnostic (CR–ve). Comprehensive clinical assessments were conducted in 532 (76%) of cases. Among the 640 CR+ve samples, 602 (94%) contained ≥2 of 3 amyloid signature proteins (ASPs) on LDMS (ASP+ve) supporting the presence of amyloid. A total of 49 of the 60 CR‐ve samples were ASP–ve; 7 of 11 that were ASP+ve were glomerular. The amyloid fibril protein was identified by LDMS in 255 of 320 (80%) of the IHC–ve samples and in a total of 545 of 640 (85%) cases overall. The LDMS and IHC techniques yielded discordant results in only 7 of 320 (2%) cases. CR histology and LDMS are corroborative for diagnosis of amyloid, but LDMS is superior to IHC for confirming amyloid type.

Biology/Disease-Driven Initiative on Protein-Aggregation Diseases of the Human Proteome Project: Goals and Progress to Date.

The Biology/Disease-driven (B/D) working groups of the Human Proteome Project are alliances of research groups aimed at developing or improving proteomic tools to support specific biological or disease-related research areas. Here, we describe the activities and progress to date of the B/D working group focused on protein aggregation diseases (PADs). PADs are characterized by the intra- or extracellular accumulation of aggregated proteins and include devastating diseases such as Parkinson's and Alzheimer's disease and systemic amyloidosis. The PAD B/D working group aims for the development of proteomic assays for the quantification of aggregation-prone proteins involved in PADs to support basic and clinical research on PADs. Because the proteins in PADs undergo aberrant conformational changes, a goal is to quantitatively resolve altered protein structures and aggregation states in complex biological specimens. We have developed protein-extraction protocols and a set of mass spectrometric (MS) methods that enable the detection and quantification of proteins involved in the systemic and localized amyloidosis and the probing of aberrant protein conformational transitions in cell and tissue extracts. In several studies, we have demonstrated the potential of MS-based proteomics approaches for specific and sensitive clinical diagnoses and for the subtyping of PADs. The developed methods have been detailed in both protocol papers and manuscripts describing applications to facilitate implementation by nonspecialized laboratories, and assay coordinates are shared through public repositories and databases. Clinicians actively involved in the PAD working group support the transfer to clinical practice of the developed methods, such as assays to quantify specific disease-related proteins and their fragments in biofluids and multiplexed MS-based methods for the diagnosis and typing of systemic amyloidosis. We believe that the increasing availability of tools to precisely measure proteins involved in PADs will positively impact research on the molecular bases of these diseases and support early disease diagnosis and a more-confident subtyping.

Hereditary Fibrinogen Aα-Chain Amyloidosis in Asia: Clinical and Molecular Characteristics.

Hereditary fibrinogen Aα-chain amyloidosis (Aα-chain amyloidosis) is a type of autosomal dominant systemic amyloidosis caused by mutations in fibrinogen Aα-chain gene (FGA). Patients with Aα-chain amyloidosis have been mainly reported in Western countries but have been rarely reported in Asia, with only five patients with Aα-chain amyloidosis being reported in Korea, China, and Japan. Clinically, the most prominent manifestation in Asian patients with Aα-chain amyloidosis is progressive nephropathy caused by excessive amyloid deposition in the glomeruli, which is similar to that observed in patients with Aα-chain amyloidosis in Western countries. In molecular features in Asian Aα-chain amyloidosis, the most common variant, E526V, was found in only one Chinese kindred, and other four kindred each had a different variant, which have not been identified in other countries. These variants are located in the C-terminal region (amino acid residues 517–555) of mature Aα-chain, which was similar to that observed in patients with Aα-chain amyloidosis in other countries. The precise number of Asian patients with Aα-chain amyloidosis is unclear. However, patients with Aα-chain amyloidosis do exist in Asian countries, and the majority of these patients may be diagnosed with other types of systemic amyloidosis.

Abdominal fat pad excisional biopsy for the diagnosis and typing of systemic amyloidosis

In the past, the diagnosis and typing of amyloidosis often required an invasive biopsy of an internal organ, such as the heart or kidneys. Abdominal fat pad excisional biopsy (FPEB) offers a less invasive approach, but the sensitivity of this technique has been unclear. To determine the sensitivity of FPEB for immunoglobulin light chain (AL) and transthyretin (ATTR) amyloidosis, we performed a retrospective clinicopathologic analysis of 97 patients who had undergone FPEB, of which 16 were positive for amyloid. The most significant pretest feature predicting a positive FPEB was a serum free light chain κ/λ ratio less than .5, and in this group of patients the probability of a positive biopsy was dependent on the size of the biopsy (P=.004). In FPEBs, the amyloid was present in multiple distinct patterns: pericellular, septal, medium-sized vessel, small vessel, and nodular. For patients with AL amyloidosis for which direct typing was attempted using the FPEB tissue, the amyloid was successfully typed in the FPEB in 90% of cases. The overall sensitivity of FPEB was 79% for AL amyloidosis and 12% for ATTR amyloidosis (P=.0003). In patients with AL amyloidosis, the sensitivity of FPEB was dependent on biopsy size, with small biopsies (≤700 mm3) having a sensitivity of ~50%, and large biopsies (>700 mm3) having a sensitivity of ~100%. This study demonstrates that FPEB has high sensitivity for AL amyloidosis, and can be routinely used to type the amyloid. However, FPEB has low sensitivity for ATTR amyloidosis in our patient population.

THIOFLAVIN T BINDING TO THE MODEL FIBRILS OF LYSOZYME: THE EFFECTS OF FIBRIL TWISTING

Amyloid fibrils are highly ordered insoluble protein aggregates that are involved in molecular etiology of a number of severe disorders, including Alzheimer's, Parkinson’s and prion’s diseases, some types of systemic amyloidosis, etc. One of the most effective approaches to detecting the amyloid fibrils is based on monitoring the spectral behavior of specific fluorescent dye Thioflavin T (ThT). Using the molecular docking and molecular dynamics tools, such as PatchDock, FireDock, CreateFibril and GROMACS, the model of twisted K-peptide fibril that supposedly represent the core region of lysozyme amyloid fibrils, has been constructed and analyzed. The effect of fibril twisting angle on the binding characteristics of ThT has been evaluated. The results obtained strongly suggest that ThT specificity for the twisted ribbon fibril polymorphs is primarily determined by the curvature effects rather than amino acid composition of fibril grooveswhich accomodate ThT molecule.

Amyloidosis: Laboratory and Clinical Perspectives

Amyloidosis is a general name for a group of rare diseases, which may end up with progressive organ damage and death as a result of the accumulation of the low-molecular-weight subgroups of normal serum proteins, after their precipitation in the extracellular tissues in the form of cross-s-folded fibrillar aggregates, which are resistant to proteolysis. More than 30,000 different proteins are produced in human cells. The first product of the protein synthesis is a linear amino acid chain (primary structure). AL amyloidosis, which is also called primary amyloidosis, is the most common and most aggressive type of systemic amyloidosis with an annual incidence of 8.9/1,000,000 in Western countries. The common signs and symptoms of AL amyloidosis are fatigue, weight loss, syncope, peripheral edema, dyspnea, diarrhea or constipation. The clinical suspicion is the first and the most important step for the diagnosis of amyloidosis. All patients with a visceral amyloid syndrome need therapy in AL amyloidosis. The goals of the current treatment approach of systemic AL amyloidosis includes rapidly reduction in the supply of the monoclonal amyloidogenic light chain by eradicating the plasma cell or B cell clone to prevent the new amyloid formation and facilitate the clearance of the existing amyloid deposits and, also supportive care to sustain the function of the organ involved and maintaining the quality of life.

Dose-Dependent Progressive Immunotherapeutic Clearance of Systemic Amyloid Deposits By Repeated Doses of Antibody to Serum Amyloid P Component (SAP)

In systemic amyloidosis, disease is caused by the extracellular accumulation of amyloid fibrils which do not elicit the normally efficient mechanisms of clearance of interstitial debris, and which progressively disrupt tissue architecture and function. Diagnosis is often late, with advanced organ dysfunction and major morbidity. The condition is usually fatal despite organ support and efforts to reduce production of the fibril precursor protein. In the most common type, AL, caused by monoclonal gammopathy, treatment with cytotoxic chemotherapy can slow or arrest amyloid deposition in some patients, and amyloid deposits may sometimes slowly regress but about 20% of patients still die within 6 months of diagnosis. No specific interventions exist for many of the rarer forms of systemic amyloidosis. Directly targeted measures are required to specifically remove amyloid deposits in order to preserve and possibly restore organ function. We have identified the normal plasma protein, serum amyloid P component (SAP), as a therapeutic target for this purpose.SAP binds to amyloid fibrils of all types and is thus always present in human amyloid deposits. Acute administration of (R)-1-[6-[(R)-2-carboxy-pyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid (CPHPC), swiftly depletes circulating SAP but leaves some SAP in amyloid deposits as an amyloid-specific antigen target. In patients with systemic AL, AA and AApoAI amyloidosis, we have lately reported that, following depletion of circulating SAP by CPHPC, a single dose of humanized monoclonal anti-SAP antibody substantially reduced the amyloid load, especially from the liver (D.B. Richards et al, New England Journal of Medicine, July 15, 2015; DOI: 10.1056/NEJMoa1504942). Here we show that repeated administration of the obligate therapeutic partnership of CPHPC with appropriate doses of anti-SAP antibody, progressively removed amyloid from the liver and other organs, including the kidney.Up to three antibody doses were given at intervals to patients, mostly with AL or AFib amyloidosis, in this second part of a phase I dose-ascending study. Treatments were generally well tolerated. Infusion reactions were largely mitigated by hydrocortisone and antihistamine premedication. Pharmacodynamic responses were associated with an early transient inflammatory cytokine response and increased CRP and SAA production, followed by substantial depletion of plasma C3 and a less marked fall in C4 and CH50. Pharmacodynamic responses were sometimes associated with self-limiting cutaneous rashes, especially in subjects without hepatic amyloidosis. Reduced amyloid load was demonstrated by radiolabelled SAP scintigraphy (liver, spleen, kidneys), extracellular volume measurement by equilibrium MRI (liver, spleen) and liver stiffness determined by transient elastography. Amyloid removal was not associated with detectable additional organ dysfunction. Abnormal liver function tests improved following clearance of hepatic amyloid. Renal parameters were stable but follow up is still too short to ascertain long term renal effects.In the preclinical mouse model, amyloid clearance mediated by anti-SAP antibody requires complement and macrophages and is effected by multinucleated giant cells. Consistent with this mechanism, the extent of amyloid clearance in patients depended on the dose of anti-SAP antibody in relation to the whole body amyloid load. In patients with hepatic and splenic amyloid, the anti-SAP antibody rapidly disappeared from the circulation, consistent with its easy access to these organs via their sinusoidal endothelium. Liver and spleen amyloid were cleared first but, after major reduction of liver and spleen load, renal amyloid was cleared by subsequent antibody doses.These preliminary observations demonstrate that progressive amyloid removal can probably be achieved in all types of systemic amyloidosis by repeated courses of CPHPC and anti-SAP antibody. A phase II study is now planned.This program is funded by GlaxoSmithKline. [Display omitted] DisclosuresPepys:Pentraxin Therapeutics Ltd: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; UK NIHR: Research Funding; UK MRC: Research Funding. Cookson:GlaxoSmithKline: Employment, Equity Ownership. Barton:GlaxoSmithKline: Employment, Equity Ownership. Berges:GlaxoSmithKline: Employment, Equity Ownership. Moon:GlaxoSmithKline: Consultancy, Research Funding. Richards:GlaxoSmithKline: Employment, Equity Ownership.

The Successful Diagnosis and Typing of Systemic Amyloidosis Using A Microwave-Assisted Filter-Aided Fast Sample Preparation Method and LC/MS/MS Analysis.

Laser microdissection followed by mass spectrometry has been successfully used for amyloid typing. However, sample contamination can interfere with proteomic analysis, and overnight digestion limits the analytical throughput. Moreover, current quantitative analysis methods are based on the spectrum count, which ignores differences in protein length and may lead to misdiagnoses. Here, we developed a microwave-assisted filter-aided sample preparation (maFASP) method that can efficiently remove contaminants with a 10-kDa cutoff ultrafiltration unit and can accelerate the digestion process with the assistance of a microwave. Additionally, two parameters (P- and D-scores) based on the exponentially modified protein abundance index were developed to define the existence of amyloid deposits and those causative proteins with the greatest abundance. Using our protocol, twenty cases of systemic amyloidosis that were well-typed according to clinical diagnostic standards (training group) and another twenty-four cases without subtype diagnoses (validation group) were analyzed. Using this approach, sample preparation could be completed within four hours. We successfully subtyped 100% of the cases in the training group, and the diagnostic success rate in the validation group was 91.7%. This maFASP-aided proteomic protocol represents an efficient approach for amyloid diagnosis and subtyping, particularly for serum-contaminated samples.

The role of abdominal fat tissue FNA for early detection and typing of systemic amyloidosis.

The role of abdominal fat tissue FNA for early detection and typing of systemic amyloidosis.

SAT0281 Prevalence of Amyloidosis in Polymyalgia Rheumatica and in Temporal Arteritis

BackgroundPolymyalgia rheumatica (PMR) or temporal arteritis (TA) may be complicated by systemic secondary AA amyloidosis (AAa). Legault and coworkers (2012) confirm this statement in a comprehensive review, although they did...