| 1. |
- Benson, Merrill D., et al.
(författare)
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Amyloid nomenclature 2018 : recommendations by the International Society of Amyloidosis (ISA) nomenclature committee
- 2018
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Ingår i: Amyloid. - : Informa UK Limited. - 1350-6129 .- 1744-2818. ; 25:4, s. 215-219
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Tidskriftsartikel (refereegranskat)abstract
- The nomenclature committee of the International Society of Amyloidosis (ISA) meets every second year to discuss and formulate recommendations. The conclusions from the discussion at the XVI International Symposium on Amyloidosis in Kumamoto, Japan, 25–29 March 2018 and afterwards are summarized in this Nomenclature Article. From having recommended the use of the designation “amyloid fibril” for in vivo material only, ISA’s nomenclature committee now accepts its use more broadly following the international scientific literature. However, it is important always to stress the origin of the β-fibrils in order to avoid misunderstanding. Given the more broad use of the word “amyloid” several classes of amyloid fibrils may be distinguished. For the medical in vivo situation, and to be included in the amyloid nomenclature list, “amyloid” still means mainly extracellular tissue deposits of protein fibrils, recognized by specific properties, such as green-yellow birefringence after staining with Congo red. It should also be underlined that in vivo amyloid fibrils, in addition to the main protein contain associated compounds, particularly serum amyloid P-component (SAP) and proteoglycans, mainly heparan sulfate proteoglycan. With this definition there are presently 36 human amyloid proteins of which 14 appear only associated with systemic amyloidosis and 19 as localized forms. Three proteins can occur both as localized and systemic amyloidosis. Strictly intracellular aggregates are not included in this list.
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| 2. |
- Benson, Merrill D., et al.
(författare)
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Amyloid nomenclature 2020 : update and recommendations by the International Society of Amyloidosis (ISA) nomenclature committee
- 2020
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Ingår i: Amyloid. - : TAYLOR & FRANCIS LTD. - 1350-6129 .- 1744-2818. ; 27:4, s. 217-222
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Tidskriftsartikel (refereegranskat)abstract
- The ISA Nomenclature Committee met electronically before and directly after the XVII ISA International Symposium on Amyloidosis, which, unfortunately, had to be virtual in September 2020 due to the ongoing COVID-19 pandemic instead of a planned meeting in Tarragona in March. In addition to confirmation of basic nomenclature, several additional concepts were discussed, which are used in scientific amyloid literature. Among such concepts are cytotoxic oligomers, protofibrils, primary and secondary nucleation, seeding and cross-seeding, amyloid signature proteins, and amyloid plaques. Recommendations for their use are given. Definitions of amyloid and amyloidosis are confirmed. Possible novel human amyloid fibril proteins, appearing as 'classical' in vivo amyloid, were discussed. It was decided to include fibulin-like extracellular matrix protein 1 (amyloid protein: AEFEMP1), which appears as localised amyloid in portal veins. There are several possible amyloid proteins under investigation, and these are included in a new Table.
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| 3. |
- Berk, John L., et al.
(författare)
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Repurposing Diflunisal for Familial Amyloid Polyneuropathy : A Randomized Clinical Trial
- 2013
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 310:24, s. 2658-2667
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE Familial amyloid polyneuropathy, a lethal genetic disease caused by aggregation of variant transthyretin, induces progressive peripheral nerve deficits and disability. Diflunisal, a nonsteroidal anti-inflammatory agent, stabilizes transthyretin tetramers and prevents amyloid fibril formation in vitro. OBJECTIVE To determine the effect of diflunisal on polyneuropathy progression in patients with familial amyloid polyneuropathy. DESIGN, SETTING, AND PARTICIPANTS International randomized, double-blind, placebo-controlled study conducted among 130 patients with familial amyloid polyneuropathy exhibiting clinically detectable peripheral or autonomic neuropathy at amyloid centers in Sweden (Umea), Italy (Pavia), Japan (Matsumoto and Kumamoto), England (London), and the United States (Boston, Massachusetts; New York, New York; and Rochester, Minnesota) from 2006 through 2012. INTERVENTION Participants were randomly assigned to receive diflunisal, 250 mg (n=64), or placebo (n=66) twice daily for 2 years. MAIN OUTCOMES AND MEASURES The primary end point, the difference in polyneuropathy progression between treatments, was measured by the Neuropathy Impairment Score plus 7 nerve tests (NIS+7) which ranges from 0 (no neurological deficits) to 270 points (no detectable peripheral nerve function). Secondary outcomes included a quality-of-life questionnaire (36-Item Short-Form Health Survey [SF-36]) and modified body mass index. Because of attrition, we used likelihood-based modeling and multiple imputation analysis of baseline to 2-year data. RESULTS By multiple imputation, the NIS+7 score increased by 25.0 (95% CI, 18.4-31.6) points in the placebo group and by 8.7 (95% CI, 3.3-14.1) points in the diflunisal group, a difference of 16.3 points (95% CI, 8.1-24.5 points; P < .001). Mean SF-36 physical scores decreased by 4.9 (95% CI, -7.6 to -2.2) points in the placebo group and increased by 1.5 (95% CI, -0.8 to 3.7) points in the diflunisal group (P < .001). Mean SF-36 mental scores declined by 1.1 (95% CI, -4.3 to 2.0) points in the placebo group while increasing by 3.7 (95% CI, 1.0-6.4) points in the diflunisal group (P = .02). By responder analysis, 29.7% of the diflunisal group and 9.4% of the placebo group exhibited neurological stability at 2 years (<2-point increase in NIS+7 score; P = .007). CONCLUSIONS AND RELEVANCE Among patients with familial amyloid polyneuropathy, the use of diflunisal compared with placebo for 2 years reduced the rate of progression of neurological impairment and preserved quality of life. Although longer-term follow-up studies are needed, these findings suggest benefit of this treatment for familial amyloid polyneuropathy.
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| 4. |
- Berk, John L, et al.
(författare)
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The diflunisal trial : study accrual and drug tolerance
- 2012
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Ingår i: Amyloid. - : Informa UK Limited. - 1350-6129 .- 1744-2818. ; 19:S1, s. 37-38
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Tidskriftsartikel (refereegranskat)abstract
- Familial amyloidotic polyneuropathy (FAP) is a protein folding disorder that induces neuropathy and cardiomyopathy, leading to death within 7-15 years after onset of clinical disease. In vitro, small ligands binding the thyroid hormone docking site stabilize tetrameric transthyretin, inhibiting amyloid fibril formation. We undertook a randomized, placebo-controlled clinical trial to determine whether diflunisal, a well-known non-steroidal anti-inflammatory drug (NSAID) alters neurologic disease progression in FAP. We enrolled 130 subjects with wide age and FAP mutation representation. To date, few recognized complications of NSAIDs have occurred in the study cohort. Data collection will be completed by November 2012.
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| 5. |
- Buxbaum, Joel N., et al.
(författare)
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Amyloid nomenclature 2022 : update, novel proteins, and recommendations by the International Society of Amyloidosis (ISA) Nomenclature Committee
- 2022
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Ingår i: Amyloid. - : Taylor & Francis Group. - 1350-6129 .- 1744-2818. ; 29:4, s. 213-219
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Tidskriftsartikel (refereegranskat)abstract
- The Nomenclature Committee of the International Society of Amyloidosis met at the XVIII International Symposium on Amyloidosis in September and virtually in October 2022 with discussions resulting in this upgraded nomenclature recommendation. The nomenclature principles remain unchanged but there is an ongoing discussion regarding the importance and varying nature of intracellular protein aggregates, particularly those associated with neurodegenerative diseases. Six novel proteins were added to the list of human amyloid fibril proteins. Of these, three are polypeptide hormones and two currently utilised peptide drugs, making the number of known iatrogenic amyloid forms four, all appearing as subcutaneous nodules at the injection site. The sixth novel amyloid fibril protein is the transmembrane 106B protein, forming intracellular amyloid fibrils in disorders associated with frontotemporal dementia. The number of known human amyloid fibril proteins is now 42.
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| 6. |
- Dispenzieri, Angela, et al.
(författare)
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Clinical and genetic profile of patients enrolled in the Transthyretin Amyloidosis Outcomes Survey (THAOS) : 14-year update
- 2022
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Ingår i: Orphanet Journal of Rare Diseases. - : BioMed Central (BMC). - 1750-1172. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Transthyretin amyloidosis (ATTR amyloidosis) is a rare, life-threatening disease caused by the accumulation of variant or wild-type (ATTRwt amyloidosis) transthyretin amyloid fibrils in the heart, peripheral nerves, and other tissues and organs.Methods: Established in 2007, the Transthyretin Amyloidosis Outcomes Survey (THAOS) is the largest ongoing, global, longitudinal observational study of patients with ATTR amyloidosis, including both inherited and wild-type disease, and asymptomatic carriers of pathogenic TTR mutations. This descriptive analysis examines baseline characteristics of symptomatic patients and asymptomatic gene carriers enrolled in THAOS since its inception in 2007 (data cutoff: August 1, 2021).Results: This analysis included 3779 symptomatic patients and 1830 asymptomatic gene carriers. Symptomatic patients were predominantly male (71.4%) and had a mean (standard deviation [SD]) age of symptom onset of 56.3 (17.8) years. Val30Met was the most common genotype in symptomatic patients in South America (80.9%), Europe (55.4%), and Asia (50.5%), and more patients had early- versus late-onset disease in these regions. The majority of symptomatic patients in North America (58.8%) had ATTRwt amyloidosis. The overall distribution of phenotypes in symptomatic patients was predominantly cardiac (40.7%), predominantly neurologic (40.1%), mixed (16.6%), and no phenotype (2.5%). In asymptomatic gene carriers, mean (SD) age at enrollment was 42.4 (15.7) years, 42.4% were male, and 73.2% carried the Val30Met mutation.Conclusions: This 14-year global overview of THAOS in over 5000 patients represents the largest analysis of ATTR amyloidosis to date and highlights the genotypic and phenotypic heterogeneity of the disease.ClinicalTrials.gov Identifier: NCT00628745.
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| 7. |
- Sekijima, Yoshiki, et al.
(författare)
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Pathological, biochemical, and biophysical characteristics of the transthyretin variant Y114H (p.Y134H) explain its very mild clinical phenotype
- 2015
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Ingår i: Journal of the peripheral nervous system. - : WILEY-BLACKWELL. - 1085-9489 .- 1529-8027. ; 20:4, s. 372-379
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Tidskriftsartikel (refereegranskat)abstract
- Transthyretin (TTR) is a homotetrameric protein that must misfold in order to form amyloid fibrils. Misfolding includes rate limiting tetramer dissociation, followed by fast tertiary structural changes of the monomer that enable aggregation. Hereditary ATTR amyloidosis is an autosomal dominant genetic disorder with systemic deposition of amyloid fibrils induced by TTR gene mutation. We identified a rare Y114H (p.Y134H) TTR variant in a Japanese patient presenting with late-onset, very mild clinical course. The patient had an extremely low serum variant TTR concentration (18% of total TTR), whereas the composition of variant TTR was 55% in amyloid fibrils in tenosynovial tissues obtained at carpal tunnel release surgery. The amyloid fibril deposits in the ATTR Y114H patient had an altered structure compared with that in wild-type ATTR patients, as determined by luminescent conjugated poly/oligo-thiophene fluorescence spectroscopy. Biophysical studies using recombinant protein showed that Y114H TTR was markedly destabilized both thermodynamically and kinetically and was highly amyloidogenic in vitro. These data suggest that extremely low serum variant Y114H TTR concentration, probably due to endoplasmic reticulum-associated degradation of unstable variant TTR protein, protected this patient from severe amyloidosis, as self-assembly of the amyloidogenic intermediate is a concentration-dependent process.
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| 8. |
- Ueda, Mitsuharu, et al.
(författare)
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SELDI-TOF mass spectrometry evaluation of variant transthyretins for diagnosis and pathogenesis of familial amyloidotic polyneuropathy.
- 2009
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Ingår i: Clinical chemistry. - : Oxford University Press (OUP). - 1530-8561 .- 0009-9147. ; 55:6, s. 1223-7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Mass spectrometric analyses are valuable for detection of transthyretin (TTR) variants, which cause familial amyloidotic polyneuropathy (FAP). However, those methods require an immunoprecipitation step with an anti-TTR antibody and are not suitable for quantitative detection. We investigated the usefulness of SELDI-TOF mass spectrometry (MS) without an immunoprecipitation step. METHODS: We used ProteinChips with chromatographic capture formats to detect TTRs. We attempted to correlate the intensity of mixed samples of amyloidogenic TTR (ATTR) V30M to wild-type (WT) TTR. We analyzed the proportion of ATTR V30M in amyloid-laden cardiac tissues from FAP patients, and also evaluated samples from FAP patients with 16 other TTR mutations. RESULTS: Detection of ATTR required only 3 h of SELDI-TOF MS analysis. We determined that SELDI-TOF MS was suitable for quantitative detection of ATTR V30M and demonstrated that the proportion of ATTR V30M to WT TTR was 46.6% in amyloid-laden cardiac tissue from an FAP patient who died 10 years after liver transplantation. With this method, we identified 12 of 17 TTR variants. Small mass shifts and low concentrations of variants prevented ATTR detection. By changing the analytical conditions, we achieved detection of low concentrations of ATTR Y114C in serum. CONCLUSIONS: SELDI-TOF MS is a reliable tool for quantitative evaluation of TTR variants, in both tissue amyloid deposits and body fluids. This method is useful for the diagnosis and investigation of the pathogenesis of FAP.
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