Bryan Lecky

119th ENMC international workshop: Trial design in adult idiopathic inflammatory myopathies, with the exception of inclusion body myositis, 10-12 October 2003, Naarden, The Netherlands

Department of Neurology, University Medical Center, Heidelberg laan 100, Utrecht, CX 3584, The Netherlands Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA The Walton Centre for Neurology and Neurosurgery, Liverpool, UK Department of Rheumatology, King’s College Hospital, London, UK Rheumatology Unit, Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, Sweden King’s Neurosciences Centre, King’s College Hospital, London, UK Institute of Rheumatology, Prague, Czech Republic Department of Neurology, Academic Medical Centre, Amsterdam, The Netherlands Department of Clinical Neurosciences, Guy’s, King’s and Thomas’ School of Medicine, London, UK

Randomized Trial of Thymectomy in Myasthenia Gravis

BACKGROUND Thymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone. METHODS We compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednisone over a 3-year period. RESULTS A total of 126 patients underwent randomization between 2006 and 2012 at 36 sites. Patients who underwent thymectomy had a lower time-weighted average Quantitative Myasthenia Gravis score over a 3-year period than those who received prednisone alone (6.15 vs. 8.99, P<0.001); patients in the thymectomy group also had a lower average requirement for alternate-day prednisone (44 mg vs. 60 mg, P<0.001). Fewer patients in the thymectomy group than in the prednisone-only group required immunosuppression with azathioprine (17% vs. 48%, P<0.001) or were hospitalized for exacerbations (9% vs. 37%, P<0.001). The number of patients with treatment-associated complications did not differ significantly between groups (P=0.73), but patients in the thymectomy group had fewer treatment-associated symptoms related to immunosuppressive medications (P<0.001) and lower distress levels related to symptoms (P=0.003). CONCLUSIONS Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis. (Funded by the National Institute of Neurological Disorders and Stroke and others; MGTX ClinicalTrials.gov number, NCT00294658.).

The clinical, histochemical, and molecular spectrum of PEO1 (Twinkle)-linked adPEO

Background: Mutations in the Twinkle (PEO1) gene are a recognized cause of autosomal dominant progressive external ophthalmoplegia (adPEO), resulting in the accumulation of multiple mitochondrial DNA (mtDNA) deletions and cytochrome c oxidase (COX)-deficient fibers in skeletal muscle secondary to a disorder of mtDNA maintenance. Patients typically present with isolated extraocular muscle involvement, with little apparent evidence of the clinical heterogeneity documented in other mtDNA maintenance disorders, in particular POLG-related disease. Methods: We reviewed the clinical, histochemical, and molecular genetics analysis of 33 unreported patients from 26 families together with all previous cases described in the literature to define the clinical phenotype associated with PEO1 mutations. Results: Ptosis and ophthalmoparesis were almost universal clinical features among this cohort, with 52% (17/33) reporting fatigue and 33% (11/33) having mild proximal myopathy. Features consistent with CNS involvement were rarely described; however, in 24% (8/33) of the patients, cardiac abnormalities were reported. Mitochondrial histochemical changes observed in muscle showed remarkable variability, as did the secondary mtDNA deletions, which in some patients were only detected by PCR-based assays and not Southern blotting. Moreover, we report 7 novel PEO1 variants. Conclusions: Our data suggest a shared clinical phenotype with variable mild multiorgan involvement, and that the contribution of PEO1 mutations as a cause of adPEO may well be underestimated. Direct sequencing of the PEO1 gene should be considered in adPEO patients prior to muscle biopsy.

A randomized controlled trial of recombinant interferon-beta 1a in Guillain-Barre syndrome

The authors recruited 19 nonambulant patients with Guillain-Barré syndrome into a pilot, double-blind, randomized, placebo-controlled safety trial of interferon beta 1a (IFNβ-1a) (Rebif). Participants received IFNβ-1a or placebo subcutaneously three times weekly, 22 μg for the first week and then 44 μg for up to 24 weeks, in addition to IV immunoglobulin (IVIg). IFNβ did not have any unexpected interaction with IVIg and there was no significant difference in rate of improvement.

Elevation of Cardiac Troponin T, But Not Cardiac Troponin I, in Patients With Neuromuscular Diseases: Implications for the Diagnosis of Myocardial Infarction

OBJECTIVES This study sought to determine the clinical and biological significance of elevated cardiac troponin T (cTnT) in patients with neuromuscular diseases. BACKGROUND Practice guidelines regard cTnT and cardiac troponin I (cTnI) as equally sensitive and specific for the diagnosis of myocardial injury. Although cTnI is unique to myocardium, cTnT can be re-expressed in skeletal muscle in response to injury. The commercial cTnT assay is claimed to be cardiac specific. METHODS Fifty-two patients with 20 different types of acquired and inherited neuromuscular diseases underwent full clinical assessment, cardiac investigations, and measurements of serum cTnT, cTnI, creatine kinase (CK), creatine kinase myocardial band (CK-MB), and N-terminal pro-B-type natriuretic peptide (NT-proBNP). RESULTS Serial measurements (265 samples) in 25 initially hospitalized patients taken during a mean of 2.4 years showed persistent elevation of cTnT (median: 0.08 μg/l; interquartile range: 0.06 to 0.14 μg/l), CK (582 U/l; 303 to 3,662 U/l), and CK-MB (24 μg/l; 8 to 34 μg/l). In contrast, cTnI, measured using 2 sensitive assays, was persistently normal throughout the study in 22 patients. Electrocardiograms (ECGs) and echocardiograms were normal in 16 and 17 patients, respectively, and no serial changes were observed. Therapeutic interventions in patients with reversible myopathies normalized cTnT, CK, and CK-MB in unison. Single measurements in 27 ambulatory patients showed elevated CK (953 U/l; 562 to 1,320 U/l), CK-MB (18 μg/l; 11 to 28 μg/l), and cTnT (0.03 μg/l; 0.02 to 0.05 μg/l) in 21, 22, and 18 patients respectively. cTnI was abnormal in only 1 patient. NT-proBNP (41 pg/ml; 35 to 97 pg/ml) was normal in all but 2 patients. ECGs were normal in 15 patients. No patients with elevated cTnT, but with normal cTnI, had any cardiovascular events in either group during follow-up. CONCLUSIONS Patients with a wide spectrum of neuromuscular diseases commonly have persistent elevation of cTnT and CK-MB in the absence of clinical and cTnI evidence of myocardial injury. Re-expressed cTnT in diseased skeletal muscle appears to be the source of the elevated cTnT detected in the circulation of these patients.

Cytosolic 5′-nucleotidase 1A autoantibody profile and clinical characteristics in inclusion body myositis

Objectives Autoantibodies directed against cytosolic 5′-nucleotidase 1A have been identified in many patients with inclusion body myositis. This retrospective study investigated the association between anticytosolic 5′-nucleotidase 1A antibody status and clinical, serological and histopathological features to explore the utility of this antibody to identify inclusion body myositis subgroups and to predict prognosis. Materials and methods Data from various European inclusion body myositis registries were pooled. Anticytosolic 5′-nucleotidase 1A status was determined by an established ELISA technique. Cases were stratified according to antibody status and comparisons made. Survival and mobility aid requirement analyses were performed using Kaplan-Meier curves and Cox proportional hazards regression. Results Data from 311 patients were available for analysis; 102 (33%) had anticytosolic 5′-nucleotidase 1A antibodies. Antibody-positive patients had a higher adjusted mortality risk (HR 1.89, 95% CI 1.11 to 3.21, p=0.019), lower frequency of proximal upper limb weakness at disease onset (8% vs 23%, adjusted OR 0.29, 95% CI 0.12 to 0.68, p=0.005) and an increased prevalence of excess of cytochrome oxidase deficient fibres on muscle biopsy analysis (87% vs 72%, adjusted OR 2.80, 95% CI 1.17 to 6.66, p=0.020), compared with antibody-negative patients. Interpretation Differences were observed in clinical and histopathological features between anticytosolic 5′-nucleotidase 1A antibody positive and negative patients with inclusion body myositis, and antibody-positive patients had a higher adjusted mortality risk. Stratification of inclusion body myositis by anticytosolic 5′-nucleotidase 1A antibody status may be useful, potentially highlighting a distinct inclusion body myositis subtype with a more severe phenotype.

Phenotypic heterogeneity in British patients with a founder mutation in the FHL1 gene

Mutations in the four-and-a-half LIM domain 1 (FHL1) gene, which encodes a 280-amino-acid protein containing four LIM domains and a single zinc-finger domain in the N-terminal region, have been associated with a broad clinical spectrum of X-linked muscle diseases encompassing a variety of different phenotypes. Patients might present with a scapuloperoneal myopathy, a myopathy with postural muscle atrophy and generalized hypertrophy, an Emery–Dreifuss muscular dystrophy, or an early onset myopathy with reducing bodies. It has been proposed that the phenotypic variability is related to the position of the mutation within the FHL1 gene. Here, we report on three British families with a heterogeneous clinical presentation segregating a single FHL1 gene mutation and haplotype, suggesting that this represents a founder mutation. The underlying FHL1 gene mutation was detected by direct sequencing and the founder effect was verified by haplotype analysis of the FHL1 gene locus. A 3-bp insertion mutation (p.Phe127_Thr128insIle) within the second LIM domain of the FHL1 gene was identified in all available affected family members of the three families. Haplotype analysis of the FHL1 region on Xq26 revealed that the families shared a common haplotype. The p.Phe127_Thr128insIle mutation in the FHL1 gene therefore appears to be a British founder mutation and FHL1 gene screening, in particular of exon 6, should therefore be indicated in British patients with a broad phenotypic spectrum of X-linked muscle diseases.

Distal weakness with respiratory insufficiency caused by the m.8344A > G "MERRF" mutation

The m.8344A > G mutation in the mt-tRNALys gene, first described in myoclonic epilepsy and ragged red fibers (MERRF), accounts for approximately 80% of mutations in individuals with MERRF syndrome. Although originally described in families with a classical syndrome of myoclonus, ataxia, epilepsy and ragged red fibers in muscle biopsy, the m.8344A > G mutation is increasingly recognised to exhibit marked phenotypic heterogeneity. This paper describes the clinical, morphological and laboratory features of an unusual phenotype in a patient harboring the m.8344A > G ‘MERRF’ mutation. We present the case of a middle-aged woman with distal weakness since childhood who also had ptosis and facial weakness and who developed mid-life respiratory insufficiency necessitating non-invasive nocturnal ventilator support. Neurophysiological and acetylcholine receptor antibody analyses excluded myasthenia gravis whilst molecular genetic testing excluded myotonic dystrophy, prompting a diagnostic needle muscle biopsy. Mitochondrial histochemical abnormalities including subsarcolemmal mitochondrial accumulation (ragged-red fibers) and in excess of 90% COX-deficient fibers, was seen leading to sequencing of the mitochondrial genome in muscle. This identified the m.8344A > G mutation commonly associated with the MERRF phenotype. This case extends the evolving phenotypic spectrum of the m.8344A > G mutation and emphasizes that it may cause indolent distal weakness with respiratory insufficiency, with marked histochemical defects in muscle. Our findings support consideration of screening of this gene in cases of indolent myopathy resembling distal limb-girdle muscular dystrophy in which screening of the common genes prove negative.

Second-line agents in myositis: 1-year factorial trial of additional immunosuppression in patients who have partially responded to steroids

Objective. Ciclosporin and MTX are used in idiopathic inflammatory myopathies (DM and PM) when patients incompletely respond to glucocorticoids. Their effectiveness is unproved in randomized controlled trials (RCTs). We evaluated their benefits in a placebo-controlled factorial RCT. Methods. A 56-week multicentre factorial-design double-blind placebo-controlled RCT compared steroids alone, MTX (15–25 mg weekly) plus steroids, ciclosporin (1–5 mg/kg/day) plus steroids and all three treatments. It enrolled adults with myositis (by Bohan and Peter criteria) with active disease receiving corticosteroids. Results. A total of 359 patients were screened and 58 randomized. Of the latter, 37 patients completed 12 months of treatment, 7 were lost to follow-up and 14 discontinued treatment. Patients completing 12 months of treatment showed significant improvement (P < 0.001 on paired t-tests) in manual muscle testing (14% change), walking time (22% change) and function (9% change). Intention to treat and completer analyses indicated that ciclosporin monotherapy, MTX monotherapy and ciclosporin/MTX combination therapy showed no significant treatment effects in comparison with placebo. Conclusion. Neither MTX nor ciclosporin (by themselves or in combination) improved clinical features in myositis patients who had incompletely responded to glucocorticoids. Trial Registration: International Standard Randomized Controlled Trial Number Register; http://www.controlled-trials.com/; ISRCTN40085050

Novel MTND1 mutations cause isolated exercise intolerance, complex I deficiency and increased assembly factor expression

Complex I (CI) is the largest of the five multi-subunit complexes constituting the human oxidative phosphorylation (OXPHOS) system. Seven of its catalytic core subunits are encoded by mitochondrial DNA (ND (NADH dehydrogenase)1–6, ND4L (NADH dehydrogenase subunit 4L)), with mutations in all seven having been reported in association with isolated CI deficiency. We investigated two unrelated adult patients presenting with marked exercise intolerance, persistent lactic acidaemia and severe muscle-restricted isolated CI deficiency associated with sub-sarcolemmal mitochondrial accumulation. Screening of the mitochondrial genome detected novel mutations in the MTND1 (NADH dehydrogenase subunit 1) gene, encoding subunit of CI [Patient 1, m.3365T>C predicting p.(Leu20Pro); Patient 2, m.4175G>A predicting p.(Trp290*)] at high levels of mitochondrial DNA heteroplasmy in skeletal muscle. We evaluated the effect of these novel MTND1 mutations on complex assembly showing that CI assembly, although markedly reduced, was viable in the absence of detectable ND1 signal. Real-time PCR and Western blotting showed overexpression of different CI assembly factor transcripts and proteins in patient tissue. Together, our data indicate that the mechanism underlying the expression of the biochemical defect may involve a compensatory response to the novel MTND1 gene mutations, promoting assembly factor up-regulation and stabilization of respiratory chain super-complexes, resulting in partial rescue of the clinical phenotype.