- Validation of Mayo Clinic Staging System for Light Chain Amyloidosis With High-Sensitivity Troponin. [Journal Article]
- JCJ Clin Oncol 2018 Nov 15; :JCO1801398
- Nephrotic Syndrome as a Presenting Feature in a Child With NLRP3 Mutation. [Journal Article]
- JCJ Clin Rheumatol 2018 Nov 14
- Efficacy of chronic BACE1 inhibition in PS2APP mice depends on the regional Aβ deposition rate and plaque burden at treatment initiation. [Journal Article]
- TTheranostics 2018; 8(18):4957-4968
- Beta secretase (BACE) inhibitors are promising therapeutic compounds currently in clinical phase II/III trials. Preclinical [18F]-florbetaben (FBB) amyloid PET imaging facilitates longitudinal monito...
Beta secretase (BACE) inhibitors are promising therapeutic compounds currently in clinical phase II/III trials. Preclinical [18F]-florbetaben (FBB) amyloid PET imaging facilitates longitudinal monitoring of amyloidosis in Alzheimer's disease (AD) mouse models. Therefore, we applied this theranostic concept to investigate, by serial FBB PET, the efficacy of a novel BACE1 inhibitor in the PS2APP mouse, which is characterized by early and massive amyloid deposition. Methods: PS2APP and C57BL/6 (WT) mice were assigned to treatment (PS2APP: N=13; WT: N=11) and vehicle control (PS2APP: N=13; WT: N=11) groups at the age of 9.5 months. All animals had a baseline PET scan and follow-up scans at two months and after completion of the four-month treatment period. In addition to this longitudinal analysis of cerebral amyloidosis by PET, we undertook biochemical amyloid peptide quantification and histological amyloid plaque analyses after the final PET session. Results: BACE1 inhibitor-treated transgenic mice revealed a progression of the frontal cortical amyloid signal by 8.4 ± 2.2% during the whole treatment period, which was distinctly lower when compared to vehicle-treated mice (15.3 ± 4.4%, p<0.001). A full inhibition of progression was evident in regions with <3.7% of the increase in controls, whereas regions with >10% of the increase in controls showed only 40% attenuation with BACE1 inhibition. BACE1 inhibition in mice with lower amyloidosis at treatment initiation showed a higher efficacy in attenuating progression to PET. A predominant reduction of small plaques in treated mice indicated a main effect of BACE1 on inhibition of de novo amyloidogenesis. Conclusions: This theranostic study with BACE1 treatment in a transgenic AD model together with amyloid PET monitoring indicated that progression of amyloidosis is more effectively reduced in regions with low initial plaque development and revealed the need of an early treatment initiation during amyloidogenesis.
- The metalloprotease ADAMTS4 generates N-truncated Aβ4-x species and marks oligodendrocytes as a source of amyloidogenic peptides in Alzheimer's disease. [Journal Article]
- ANActa Neuropathol 2018 Nov 13
- Brain accumulation and aggregation of amyloid-β (Aβ) peptides is a critical step in the pathogenesis of Alzheimer's disease (AD). Full-length Aβ peptides (mainly Aβ1-40 and Aβ1-42) are produced throu...
Brain accumulation and aggregation of amyloid-β (Aβ) peptides is a critical step in the pathogenesis of Alzheimer's disease (AD). Full-length Aβ peptides (mainly Aβ1-40 and Aβ1-42) are produced through sequential proteolytic cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. However, studies of autopsy brain samples from AD patients have demonstrated that a large fraction of insoluble Aβ peptides are truncated at the N-terminus, with Aβ4-x peptides being particularly abundant. Aβ4-x peptides are highly aggregation prone, but their origin and any proteases involved in their generation are unknown. We have identified a recognition site for the secreted metalloprotease ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs 4) in the Aβ peptide sequence, which facilitates Aβ4-x peptide generation. Inducible overexpression of ADAMTS4 in HEK293 cells resulted in the secretion of Aβ4-40 but unchanged levels of Aβ1-x peptides. In the 5xFAD mouse model of amyloidosis, Aβ4-x peptides were present not only in amyloid plaque cores and vessel walls, but also in white matter structures co-localized with axonal APP. In the ADAMTS4-/- knockout background, Aβ4-40 levels were reduced confirming a pivotal role of ADAMTS4 in vivo. Surprisingly, in the adult murine brain, ADAMTS4 was exclusively expressed in oligodendrocytes. Cultured oligodendrocytes secreted a variety of Aβ species, but Aβ4-40 peptides were absent in cultures derived from ADAMTS4-/- mice indicating that the enzyme was essential for Aβ4-x production in this cell type. These findings establish an enzymatic mechanism for the generation of Aβ4-x peptides. They further identify oligodendrocytes as a source of these highly amyloidogenic Aβ peptides.
- Primary idiopathic CNS non-amyloidogenic light chain deposition disease complicated by treatment-resistant focal seizure disorder. [Journal Article]
- JCJ Clin Neurosci 2018 Nov 10
- Light chain deposition disease (LCDD) is a systemic disorder characterised by the pathologic deposition of immunoglobulin light chains, which is histologically distinguished from amyloidosis by failu...
Light chain deposition disease (LCDD) is a systemic disorder characterised by the pathologic deposition of immunoglobulin light chains, which is histologically distinguished from amyloidosis by failure to stain with Congo red. Central nervous system (CNS)-restricted LCDD is among the rarest manifestations. We describe a unique case complicated by focal onset epilepsy with impaired awareness for which control with anticonvulsant therapy proved difficult.
- Which definition should be used to determine colchicine resistance among patients with familial Mediterranean fever? [Journal Article]
- CEClin Exp Rheumatol 2018 Nov 12
- CONCLUSIONS: Definition of colchicine resistance is still controversial. Definitions with both clinical and laboratory criteria were met by a higher percentage of resistant patients than those without laboratory criteria. However, the proper definitions for the attack-free period and persistence of APRs are still lacking.
- A new heterozygous G duplicate in exon1 (c.100dupG) of gelsolin gene causes Finnish gelsolin amyloidosis in a Chinese family. [Journal Article]
- BBBrain Behav 2018 Nov 12; :e01151
- CONCLUSIONS: We presented a new autosomal dominant heterozygous G duplicate mutation in exon1 of GSN gene, leading to FGA in a Chinese family.
- Isolated Laryngeal Amyloidosis Mimicking Laryngeal Cancer. [Journal Article]
- CCureus 2018 Aug 06; 10(8):e3106
- Amyloidosis is the deposition of an extracellular fibrillar protein in the tissues leading to organ dysfunction. Laryngeal amyloidosis is a rare phenomenon. We report a case of isolated laryngeal amy...
Amyloidosis is the deposition of an extracellular fibrillar protein in the tissues leading to organ dysfunction. Laryngeal amyloidosis is a rare phenomenon. We report a case of isolated laryngeal amyloidosis which was initially suspicious for laryngeal cancer on magnetic resonance imaging (MRI) but histopathology showed the presence of amyloid. Systemic workup was negative. The patient is being managed conservatively.
- Suspected Pericardial Tuberculosis Revealed as an Amyloid Pericardial Mass. [Journal Article]
- CRCase Rep Hematol 2018; 2018:8606430
- Primary systemic amyloidosis is not easily diagnosed. The immunoglobulin deposits are usually localized in the kidney, heart, and liver. We describe an unusual case of a patient suffering from a peri...
Primary systemic amyloidosis is not easily diagnosed. The immunoglobulin deposits are usually localized in the kidney, heart, and liver. We describe an unusual case of a patient suffering from a pericardial amyloidoma with internal calcifications and air bubbles that compressed the right ventricle and shifted the heart to the left. Since the patient was in shock, urgent pericardiotomy was performed. This site showed PET uptake. A monoclonal component was present. On these findings, differential diagnoses included multiple myeloma and atypical pericardial tuberculosis, whereas a periumbilical fat tissue biopsy demonstrated amyloidosis. A previous Salmonella species infection had most likely stimulated the production of amyloid. The patient received bortezomib/dexamethasone treatment and achieved a good response.
New Search Next
- The Broad-Ranging Panorama of Systemic Autoinflammatory Disorders with Specific Focus on Acute Painful Symptoms and Hematologic Manifestations in Children. [Review]
- MJMediterr J Hematol Infect Dis 2018; 10(1):e2018067
- Systemic autoinflammatory disorders (SAIDs) are inherited defects of innate immunity characterized by recurrent sterile inflammatory attacks involving skin, joints, serosal membranes, gastrointestina...
Systemic autoinflammatory disorders (SAIDs) are inherited defects of innate immunity characterized by recurrent sterile inflammatory attacks involving skin, joints, serosal membranes, gastrointestinal tube, and other tissues, which recur with variable rhythmicity and display reactive amyloidosis as a potential long-term complication. Dysregulated inflammasome activity leading to overproduction of many proinflammatory cytokines, such as interleukin-1 (IL-1), and delayed shutdown of inflammation are considered crucial pathogenic keys in the vast majority of SAIDs. Progress of cellular biology has partially clarified the mechanisms behind monogenic SAIDs, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, cryopyrin-associated periodic syndrome, mevalonate kinase deficiency, hereditary pyogenic diseases, idiopathic granulomatous diseases and defects of the ubiquitin-proteasome pathway. Whereas, little is clarified for the polygenic SAIDs, such as periodic fever, aphthous stomatitis, pharyngitis, and cervical adenopathy (PFAPA) syndrome. The puzzle of symptomatic febrile attacks recurring over time in children requires evaluating the mixture of clinical data, inflammatory parameters in different disease phases, the therapeutic efficacy of specific drugs such as colchicine, corticosteroids or IL-1 antagonists, and genotype analysis in selected cases. The long-term history of periodic fevers should also need to rule out chronic infections and malignancies. This review is conceived as a practical template for proper classification of children with recurring fevers and includes tips useful for the diagnostic approach to SAIDs, focusing on the specific acute painful symptoms and hematologic manifestations encountered in childhood.