Sasha Zivkovic's research while affiliated with Yale University and other places

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Publications (18)


TTR gene silencing therapy in post liver transplant hereditary ATTR amyloidosis patients
  • Article

June 2020

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31 Reads

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21 Citations

Orly Moshe-Lilie

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Stephen B. Heitner

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Chafic Karam

Objective: Patients with hereditary transthyretin (TTR) amyloidosis (hATTR) often experience disease progression after orthotopic liver transplant (POLT) due in part to wild type ATTR amyloid deposition. The management strategy is not defined. We propose that TTR gene silencing with an antisense oligonucleotide or a small interfering ribonucleic acid may be a treatment for these patients. Methods: We reviewed the charts of hATTR patients POLT treated with a TTR gene silencing agent at 7 different Amyloid Clinics between 2018–2020. Results: Nine hATTR patients with POLT were treated with TTR gene silencing therapy (Inotersen). The median age was 61 years. The median time from OLT to initiation of TTR gene silencing therapy was 7.5 years. The median duration of therapy was 12 months. Neuropathy impairment score remained stable or improved in all patients. Five patients stopped treatment: 3 because of thrombocytopenia, 2 because of reversible liver rejection. Three patients who discontinued treatment subsequently experienced worsening of their neuropathy. Conclusion: TTR gene silencing therapy in hATTR patients with POLT could be a treatment option. Vigilant monitoring of renal, liver and bone marrow functions is necessary because of frequent complications. Further studies are needed to determine efficacy.

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Quality Measures in Electrodiagnosis: Carpal Tunnel Syndrome an AANEM Quality Measure Set

January 2020

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37 Reads

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10 Citations

Muscle & Nerve

Carpal tunnel syndrome (CTS) is a common neuromuscular condition and a major cause of work‐related disability. As healthcare in the United States transitions towards a value‐based system from fee‐for‐service, quality measures assume importance in the evaluation of care provided. This report from the American Association of Electrodiagnostic and Neuromuscular Medicine (AANEM) Quality Improvement Committee provides an introduction to quality measures and outlines a quality measurement set for the electrodiagnosis of CTS. The measures attempt to standardize technical requirements for electrodiagnostic (EDX) studies of CTS, the criteria for diagnosing median neuropathy at the wrist and assessing its severity, and the role of pre‐operative EDX testing. The assumption is that implementation of these measures will improve the accuracy of CTS diagnosis when EDX is performed, help exclude mimics and therefore improve care of patients with CTS with the ultimate goal of improving outcomes. Post‐implementation assessment of outcomes will refine these measures. This article is protected by copyright. All rights reserved.




Table 1 Clinical and demographic characteristics of TIA1 mutation carriers
Fig. 2 Histological changes in TIA1 mutation carriers. Cross section of spinal cord showing severe loss of myelin stain in the corticospinal tracts (CST) (a). Lower motor neurons containing Bunina bodies (arrow) (b) and large, round cored Lewy body-like inclusions (LBLI) (c, d) or round eosinophilic inclusions without distinct cores (e) were present in the medulla and spinal cord. Extra-motor pathology included chronic degeneration with superficial, laminar microvacuolation of the prefrontal cortex (f). a and e, HE/LFB stain; b-d and f, HE stain. Scale bar: a, 1200 μm; b, 7 μm, c, 23 μm; d and e, 15 μm; f, 205 μm 
Table 2 Semiquantitative analysis of neurodegeneration and TDP-ir pathology in TIA1 mutation carriers
Fig. 3 TDP-43 immunoreactive pathology in TIA1 mutation carriers. Numerous predominantly granular TDP-43 immunoreactive (TDP-ir) neuronal cytoplasmic inclusions (NCI, arrows) were present in the prefrontal cortex (a) and primary motor cortex (b). Hippocampal dentate granule cells (c) and dopaminergic neurons in the substantia nigra (d) were consistently affected in all cases. Lower motor neurons (LMN) of the medulla and spinal cord (e-i) contained NCI that were granular (e), filamentous (f) or round and compact (g and h). Single LMN containing combinations of NCI types were not uncommon (i, arrow points to filamentous inclusions in close proximity to a compact, round NCI). Phosphorylationindependent TDP-43 immunohistochemistry. Scale bar: a and i, 25 μm; b, c and e, 18 μm; d and g, 36 μm; f and h, 9 μm 
Table 3 TIA1 antibodies used for immunohistochemistry and double label immunofluorescence

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Clinical and neuropathological features of ALS/FTD with TIA1 mutations
  • Article
  • Full-text available

December 2017

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578 Reads

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38 Citations

Acta Neuropathologica Communications

Mutations in the stress granule protein T-cell restricted intracellular antigen 1 (TIA1) were recently shown to cause amyotrophic lateral sclerosis (ALS) with or without frontotemporal dementia (FTD). Here, we provide detailed clinical and neuropathological descriptions of nine cases with TIA1 mutations, together with comparisons to sporadic ALS (sALS) and ALS due to repeat expansions in C9orf72 (C9orf72+). All nine patients with confirmed mutations in TIA1 were female. The clinical phenotype was heterogeneous with a range in the age at onset from late twenties to the eighth decade (mean = 60 years) and disease duration from one to 6 years (mean = 3 years). Initial presentation was either focal weakness or language impairment. All affected individuals received a final diagnosis of ALS with or without FTD. No psychosis or parkinsonism was described. Neuropathological examination on five patients found typical features of ALS and frontotemporal lobar degeneration (FTLD-TDP, type B) with anatomically widespread TDP-43 proteinopathy. In contrast to C9orf72+ cases, caudate atrophy and hippocampal sclerosis were not prominent. Detailed evaluation of the pyramidal motor system found a similar degree of neurodegeneration and TDP-43 pathology as in sALS and C9orf72+ cases; however, cases with TIA1 mutations had increased numbers of lower motor neurons containing round eosinophilic and Lewy body-like inclusions on HE stain and round compact cytoplasmic inclusions with TDP-43 immunohistochemistry. Immunohistochemistry and immunofluorescence failed to demonstrate any labeling of inclusions with antibodies against TIA1. In summary, our TIA1 mutation carriers developed ALS with or without FTD, with a wide range in age at onset, but without other neurological or psychiatric features. The neuropathology was characterized by widespread TDP-43 pathology, but a more restricted pattern of neurodegeneration than C9orf72+ cases. Increased numbers of round eosinophilic and Lewy-body like inclusions in lower motor neurons may be a distinctive feature of ALS caused by TIA1 mutations.

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Electrodiagnostic Studies in the Intensive Care Unit: A Comparison Study Two Decades Later: EDX in the ICU

October 2017

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32 Reads

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6 Citations

Muscle & Nerve

Introduction: Since the late 1980s, critical illness myopathy (CIM) and polyneuropathy (CIP) have been increasingly recognized in the intensive care unit (ICU). We explored whether these causes of ICU weakness were now more likely to lead to electrodiagnostic studies (EDX) at our institution than they were 19-20 years earlier. Methods: We reviewed 100 consecutive ICU patients who underwent EDX from 2009-2015 and compared them to a previously reported study population from 1990-1995.(10) Results: Thirty-seven (39%) had CIM, CIP, or both versus 55% in the previous study (p=0.04). Thirty-four (36%) were diagnosed with "traditional" pre-ICU causes of weakness, such as motor neuron disease or Guillain-Barre syndrome, versus 29% in the earlier study (p=0.3). Discussion: CIM and CIP continue to be common disorders that lead to ICU EDX, but their proportion declined compared to 19-20 years earlier, possibly due to the perceived role and selective use of EDX in the ICU. This article is protected by copyright. All rights reserved.


TIA1 Mutations in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Promote Phase Separation and Alter Stress Granule Dynamics

August 2017

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1,248 Reads

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495 Citations

Neuron

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are age-related neurodegenerative disorders with shared genetic etiologies and overlapping clinical and pathological features. Here we studied a novel ALS/FTD family and identified the P362L mutation in the low-complexity domain (LCD) of T cell-restricted intracellular antigen-1 (TIA1). Subsequent genetic association analyses showed an increased burden of TIA1 LCD mutations in ALS patients compared to controls (p = 8.7 × 10⁻⁶). Postmortem neuropathology of five TIA1 mutations carriers showed a consistent pathological signature with numerous round, hyaline, TAR DNA-binding protein 43 (TDP-43)-positive inclusions. TIA1 mutations significantly increased the propensity of TIA1 protein to undergo phase transition. In live cells, TIA1 mutations delayed stress granule (SG) disassembly and promoted the accumulation of non-dynamic SGs that harbored TDP-43. Moreover, TDP-43 in SGs became less mobile and insoluble. The identification of TIA1 mutations in ALS/FTD reinforces the importance of RNA metabolism and SG dynamics in ALS/FTD pathogenesis.



Citations (8)


... However, during the major outbreak, nearly all of the cases (11/13) with GBS were classified as AIDP, which was consistent with previous studies [7,30], providing phenotypic evidence of association between SARS-CoV-2 infection and GBS. Accordingly, COVID-GBS patients exhibited higher prevalence of cranial nerve involvement and CSF protein concentrations, similar to patients with AIDP [4,31]. The symptoms of COVID-19 in most patients with COVID-GBS were mild in this study, different from previous case reports [7], which indicated that occurrence of GBS was independent of the severity of COVID-19. ...

Reference:

Relative frequencies and clinical features of Guillain-Barré Syndrome before and during the COVID-19 pandemic in North China
Cerebrospinal Fluid Findings in Relation to Clinical Characteristics, Subtype, and Disease Course in Patients With Guillain-Barré Syndrome

Neurology

... Raw data from the first nerve conduction study (NCS) and local reference values were used to classify each study. The results were classified according to Hadden criteria as demyelinating (AIDP), motor axonal (AMAN), sensorimotor axonal neuropathy (AMSAN) [7,12,13,[38][39][40][41]. Laboratory tests included complete CSF analysis. ...

Electrodiagnosis of Guillain-Barre syndrome in the International GBS Outcome Study: Differences in methods and reference values
  • Citing Article
  • January 2022

Clinical Neurophysiology

... 3,4 In addition, the side-effect profile of COVID-19 vaccination in patients with channelopathies is unknown. 5 Because of concerns over the risk of venous or arterial thromboembolism with some vaccines, the risk profile is unclear in patients with channelopathies who have impaired ambulation or may be more sedentary. 6,7 Driven predominantly by the need to practice cautiously in an unknown era, recommendations and guidelines were created to broadly advise patients with neuromuscular disorders. ...

Doctor – Should I get the COVID‐19 vaccine? Infection and Immunization in Individuals with Neuromuscular Disorders

Muscle & Nerve

... Other potential ALS drugs targeting neuronal hyperactivity or excitotoxicity have been reported; memantine, a noncompetitive antagonist of N-methyl-D-aspartic acid (NMDA) receptors, has been shown to delay disease progression and prolong survival of SOD1 mutant ALS model mice [181] but has not demonstrated therapeutic benefits for ALS patients [182]. Mexiletine, a sodium channel blocker, has been shown to inhibit neuronal hyperexcitability and reduce the frequency of muscle clump [183,184], but it is ineffective in inhibiting disease progression [185]. Ezogabine, an activator of Kv7 potassium channels, has been shown to reduce neuronal excitability in vitro and in vivo [186,187]. ...

Effects of Mexiletine on Hyperexcitability in Sporadic ALS : Preliminary Findings from A Small Phase II Randomized Controlled Trial

Muscle & Nerve

... Additionally, domino liver transplant recipients may develop acquired hATTR-PN from variant TTR produced by allograft [43]. Gene silencers have been used in patients who developed progression of hATTR after liver transplantation [44,45]. With the advent of new more effective therapies, the use of liver transplantation for hATTR has significantly declined [36]. ...

TTR gene silencing therapy in post liver transplant hereditary ATTR amyloidosis patients
  • Citing Article
  • June 2020

... The inclusion criteria 1) positive modified Phalen test; 2) W-MR image taken within 1 year; 3) confirmation by a nerve conduction examination according to the American Academy of Neurology standards. [16] The exclusion criteria 1) double crush syndrome; 2) wrist fracture; ...

Quality Measures in Electrodiagnosis: Carpal Tunnel Syndrome an AANEM Quality Measure Set
  • Citing Article
  • January 2020

Muscle & Nerve

... Disease related mutations the key RNA-binding proteins of stress granules including TIA1 cause the stress granules to become less dynamic and soluble, and become prone to amyloid nucleation in neurodegenerative diseases. (6)(7)(8) Increasing evidence suggests that liquid-liquid phase separation of TIA and other proteins underlies the formation of stress granules, analogous to many other membrane-less cellular structures. (9) Though the complex network of molecular interactions among their components makes it hard to determine precise mechanistic details of SGs formation, models have been proposed for SGs assembly, and the low-complexity domains of the RNA-binding proteins such as TIA1 appear to be key regulators of liquid-liquid phase separation. ...

Clinical and neuropathological features of ALS/FTD with TIA1 mutations

Acta Neuropathologica Communications

... 5,6 Comparable to other RNA-binding proteins, disrupting the function of TIA1 can lead to various diseases including cancer, 7-9 autoimmune diseases 10 and neurodegenerative disorders. [11][12][13][14] Studies have demonstrated that mutations to the TIA1 gene may delay the disassembly of stress granule, resulting in insoluble and immobile stress granules, a clinical feature of ALS and FTD. 6,11 Significant efforts are required to further elucidate the relationship between dysregulated RNA metabolism and ALS/FTD pathogenesis which may lead to novel therapeutic discoveries. ...

TIA1 Mutations in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Promote Phase Separation and Alter Stress Granule Dynamics
  • Citing Article
  • August 2017

Neuron