Publications by authors named "Michael Polydefkis"

Importance: There is a lack of long-term efficacy and safety data on hereditary transthyretin amyloidosis with polyneuropathy (hATTR-PN) and on RNA interference (RNAi) therapeutics in general. This study presents the longest-term data to date on patisiran for hATTR-PN.

Objective: To present the long-term efficacy and safety of patisiran in adults with hATTR-PN.

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Background: The NEURO-TTRansform trial showed that after 66 weeks of treatment, eplontersen significantly reduced neuropathic impairment and improved quality of life (QoL) in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy (ATTRv-PN). In this secondary analysis from NEURO-TTRansform, autonomic impairment, and the impact of eplontersen on autonomic impairment progression was evaluated through 85 weeks in patients randomised to eplontersen ( = 144) versus external placebo ( = 60; through Week 66 from the NEURO-TTR trial).

Methods: Change from baseline in modified Neuropathy Impairment Score +7 (mNIS+7) composite score, Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QoL-DN) total score, and the Neuropathy Symptoms and Change (NSC) total score was evaluated.

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Background And Aims: Peripheral neuropathy (PN) is a common neurological condition in elderly adults. Vitamin D deficiency has been associated with diabetic and chemotherapy-induced neuropathy, but its role in idiopathic PN, in which no underlying cause of neuropathy can be identified, has not been investigated.

Methods: Two hundred thirty patients with idiopathic PN enrolled in the Peripheral Neuropathy Research Registry (PNRR) at Johns Hopkins University School of Medicine had vitamin D testing information on record.

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This article has been co-authored by a patient living with hereditary transthyretin (ATTRv) amyloidosis and a neurologist. This rare, progressive disease is associated with impairment of multiple organ systems, including the nerves, heart, and the gastrointestinal tract, forcing patients to live with and adapt to a range of debilitating symptoms. Here, the patient and physician discuss how the symptoms of ATTRv amyloidosis profoundly impact day to day life, the difficulties with identifying the disease, and how this effects the diagnosis experience.

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Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is associated with significant mortality. The Val122Ile variant, highly prevalent in Black patients, portends poorer survival compared with other ATTR-CM subtypes. Although Val122Ile is biologically more aggressive, the contribution of race and socioeconomic status (SES) to disease outcomes in patients with ATTR-CM is undefined.

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Article Synopsis
  • Ritlecitinib, a drug being tested for alopecia areata, caused reversible axonal swelling and auditory potential changes in dogs at doses higher than what's approved for humans.
  • * A phase 2a study evaluated the effects of ritlecitinib on auditory and nerve fiber changes in 71 patients, comparing results with a placebo group over 9 months.
  • * Findings showed no significant differences in auditory or nerve fiber measures between the treatment and placebo groups, suggesting that dog toxicity findings may not apply to human patients.
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Introduction: We examined autoimmunity markers (AIM) and autonomic dysfunction in patients with chronic neurogastroenterological symptoms and their relationship to joint hypermobility/hypermobility spectrum disorder (JH/HSD).

Methods: AIM positivity was defined as a diagnosis of known autoimmune/autoinflammatory disorder with at least 1 positive seromarker of autoimmunity or at least 2 positive seromarkers by themselves. Three cohorts were studied: (i) retrospective (n = 300), (ii) prospective validation cohort (n = 133), and (iii) treatment cohort (n = 40), administered open-label intravenous immunoglobulin (IVIG).

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  • SLURP1 and SLURP2 are proteins linked to a skin condition called Mal de Meleda (MdM), which causes painful thickening of skin on the palms and soles due to genetic mutations.
  • Mouse models lacking SLURP1 or SLURP2 exhibit similar skin thickening and show increased pain sensitivity to touch and temperature.
  • The study found that these mice have changes in skin immune response and nerve activity, suggesting they could help in developing treatments for pain related to this skin condition.
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  • A systematic review analyzed studies on NfL levels in patients with systemic amyloidosis, including data from 1604 participants, revealing that higher NfL levels indicate the presence of polyneuropathy.
  • The findings suggest NfL can be useful for early detection, monitoring of disease progression, and evaluating treatment responses in systemic amyloidosis, though it shouldn't be used as a final outcome measure.
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Although most patients with cardiac amyloidosis are diagnosed with either light chain (AL) or transthyretin (ATTR) disease, coexisting amyloid subtypes can occur. We present three cases of coexisting AL and ATTR cardiac amyloidosis and demonstrate the importance of clinical history and endomyocardial biopsy in diagnosis of this rare entity.

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Hereditary transthyretin (ATTRv; v for variant) amyloidosis is a rare, multisystem, progressive, and fatal disease in which polyneuropathy is a cardinal manifestation. Due to a lack of United States (US)-specific guidance on ATTRv amyloidosis with polyneuropathy, a panel of US-based expert clinicians convened to address identification, monitoring, and treatment of this disease. ATTRv amyloidosis with polyneuropathy should be suspected in unexplained progressive neuropathy, especially if associated with systemic symptoms or family history.

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Hereditary transthyretin (TTR) amyloid polyneuropathy is an autosomal dominant life-threatening disorder. TTR is produced mainly by the liver but also by the choroid plexus and retinal pigment epithelium. Detailed clinical characterisation, identification of clinical red flags for misdiagnosis, and use of biomarkers enable early diagnosis and treatment.

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Background: Longitudinal changes in neurofilament light chain (NfL) levels were evaluated alongside prespecified clinical assessments 24 months into the patisiran Global open-label extension (OLE) study in patients with ATTRv amyloidosis with polyneuropathy.

Methods: All patients enrolled in the Global OLE, from phase III APOLLO and phase II OLE parent studies, received patisiran. Assessments included measures of polyneuropathy (modified Neuropathy Impairment Score+7 (mNIS+7)), quality of life (QOL; Norfolk QOL-Diabetic Neuropathy questionnaire (Norfolk QOL-DN)), and plasma NfL.

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Background And Objectives: Hereditary transthyretin amyloidosis (hATTR) is a rare autosomal dominant systemic disease with variable penetrance and heterogeneous clinical presentation. Several effective treatments can reduce mortality and disability, though diagnosis remains challenging, especially in the United States where disease is nonendemic. Our aim is to describe the neurologic and cardiac characteristics of common US ATTR variants V122I, L58H, and late-onset V30M at presentation.

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Article Synopsis
  • Hereditary transthyretin amyloidosis (hATTR/ATTRv) is caused by the buildup of misfolded transthyretin protein, affecting peripheral nerves, and inotersen has shown promise in treating the associated polyneuropathy, according to the NEURO-TTR study results.
  • The study included patients from Europe and North America who participated in a long-term open-label extension study, focusing on various efficacy measures like the modified Neuropathy Impairment Score and quality of life assessments while also monitoring safety.
  • Results indicated that a significant proportion of patients improved or maintained their neurological function over time, with 39 patients who initially received a placebo showing notable progress
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  • The study evaluated vutrisiran, an RNA therapy aimed at reducing transthyretin (TTR) production, in patients with hereditary transthyretin (ATTRv) amyloidosis affecting the nerves.
  • The phase 3 HELIOS-A trial involved 164 patients, comparing vutrisiran (administered every 3 months) to patisiran (administered every 3 weeks) and an external placebo group, assessing various health outcomes over 18 months.
  • Results showed that vutrisiran led to significant improvements in neuropathy scores and quality of life compared to placebo, with a good safety profile and no serious drug-related complications.*
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Background And Objectives: Various peripheral neuropathies, particularly those with sensory and autonomic dysfunction may occur during or shortly after acute COVID-19 illnesses. These appear most likely to reflect immune dysregulation. If similar manifestations can occur with the vaccination remains unknown.

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Transthyretin cardiac amyloidosis (ATTR and ATTRv) is an underrecognized cause of heart failure that results from myocardial deposition of misfolded protein (TTR or prealbumin). The diagnosis can be confirmed by uptake of 99m Tc-pyrophosphate ( 99m Tc-PYP) in the heart with serologic studies to rule out light chain disease. We present the case of a 70-year-old woman who underwent a 99m Tc-PYP scan.

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Nine-banded armadillos develop peripheral neuropathy after experimental Mycobacterium leprae infection that recapitulates human disease. We used an intracutaneous excision axotomy model to assess the effect of infection duration by M. leprae on axonal sprouting and Schwan cell density.

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Background: Hereditary transthyretin-mediated amyloidosis, also known as ATTRv amyloidosis (v for variant), is a rare, autosomal dominant, fatal disease, in which systemic amyloid progressively impairs multiple organs, leading to disability and death. The recent approval of disease-modifying therapies offers the hope of stabilization or eventual reversal of disease progression, and yet highlights a lack of disease-management guidance. A multidisciplinary panel of expert clinicians from France and the US came to consensus on monitoring the disease and identifying progression through a clinical opinion questionnaire, a roundtable meeting, and multiple rounds of feedback.

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Ethoxyquin (EQ), a quinolone-based antioxidant, has demonstrated neuroprotective properties against several neurotoxic drugs in a phenotypic screening and is shown to protect axons in animal models of chemotherapy-induced peripheral neuropathy. We assessed the effects of EQ on peripheral nerve function in the db/db mouse model of type II diabetes. After a 7 week treatment period, 12-week-old db/db-vehicle, db/+ -vehicle and db/db-EQ treated animals were evaluated by nerve conduction, paw withdrawal against a hotplate, and fiber density in hindlimb footpads.

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Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain.

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