Granulomatous Myositis Associated with Extremely Elevated Anti-striated Muscle Antibodies in the Absence of Myasthenia Gravis

It has been suggested that antibodies against nonacetylcholine receptor proteins of striated muscle are markers of the presence of a thymic epithelial tumor in patients with myasthenia gravis (MG). These antibodies may be measured using an immunofluorescence assay against striated muscle(anti-STR) or an ELISA with a recombinant 30-kd titin fragment (anti-MGT30). To directly compare anti-STR with anti-MGT30, we examined the sera of 276 consecutive patients with known or suspected MG. Definite diagnoses and thymic histology, if available, were correlated with the antibody assays. Of the 276 patients, 164 had MG. Thymic histology was obtained in 44 patients: 18 had lymphofollicular hyperplasia, 13 thymic epithelial tumors, 8 atrophy, and 5 were normal. When compared with anti-STR, anti-MGT30 showed a sensitivity of 69% (STR 77%), specificity of 100% (STR 56%, p = 0.026), negative predictive value of 82% (STR 77%), and positive predictive value of 100% (STR 56%, p = 0.003) for the identification of a thymic epithelial tumor versus thymic hyperplasia. We conclude that the anti-MGT30 ELISA is better than the anti-STR immunofluorescence assay for the diagnosis of paraneoplastic MG.

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Myasthenia Gravis in Pregnancy Treated With Daily Massive Vitamin D Dose

Asploro Journal of Biomedical and Clinical Case Reports ◽

10.36502/2020/asjbccr.6208 ◽

2020 ◽

Vol 3 (2) ◽

pp. 171-177

Author(s):

Silva LFF ◽

Martins MC ◽

Caplum MC ◽

Luz MS ◽

Amaral VM ◽

...

Keyword(s):

Vitamin D ◽

T Cells ◽

Myasthenia Gravis ◽

Striated Muscle ◽

First Trimester ◽

Effector T Cells ◽

Myasthenic Crisis ◽

First Trimester Of Pregnancy ◽

Muscle Groups ◽

In Pregnancy

Myasthenia gravis (MG) is an autoimmune disease affecting the motor endplate of striated muscle. It is caused by antibodies that act in the cholinergic receptors at the post-synaptic portion of the neuromuscular junction, which results in asthenia and fatigue in some muscle groups. In pregnancy, it’s unpredictable, because pregnant women can present MG exacerbation, remission, stability, or even a myasthenic crisis during pregnancy. Complications are more frequent in the first trimester of pregnancy and the first 30 days of puerperium. Vitamin D and its metabolites are potent immunomodulators since their immuno-regulatory effect directly inhibits effector T cells and induces regulatory T cells (Treg) to decrease the production of inflammatory cytokines. The authors present a case report of a patient with MG who was treated throughout pregnancy with massive doses of vitamin D, obtaining good results.

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ACETYLCHOLINE-RECEPTOR-BLOCKING FACTOR AND STRIATED-MUSCLE ANTIBODY IN MYASTHENIA GRAVIS

The Lancet ◽

10.1016/s0140-6736(76)93050-6 ◽

1976 ◽

Vol 307 (7974) ◽

pp. 1405-1406 ◽

Cited By ~ 1

Author(s):

ArthurJ.L. Strauss

Keyword(s):

Myasthenia Gravis ◽

Acetylcholine Receptor ◽

Striated Muscle ◽

Receptor Blocking ◽

Blocking Factor

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NCMP-18. FIXED PTOSIS AS A SYMPTOM OF MYOSITIS SECONDARY TO CHECKPOINT INHIBITION

Neuro-Oncology ◽

10.1093/neuonc/noab196.589 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi150-vi150

Author(s):

Ashley Aaroe ◽

Sudhakar Tummala

Keyword(s):

Myasthenia Gravis ◽

Striated Muscle ◽

Rapid Onset ◽

Cancer Center ◽

High Dose ◽

Post Discharge ◽

Institutional Review ◽

Number Of Patients ◽

Average Maximum

Abstract BACKGROUND A growing number of patients with cancer receive checkpoint inhibitor (CPI) based immunotherapy. Peripheral nervous system toxicities including myositis, myasthenia gravis and inflammatory neuropathy are distinct from their non immunotherapy-related equivalents, with unique clinical presentations and therapeutic considerations. METHODS Patients with CPI myositis and non-fatigable ptosis were identified, and clinical data was retrospectively extracted from the electronic medical record in compliance with MD Anderson Cancer Center Institutional Review Board guidelines. RESULTS 14 patients were identified. Average maximum creatine kinase (CK) was 3571 U/L (range 20-19,794). 9 patients had electromyography and nerve conduction studies documented in our system; all had electrodiagnostic evidence of myopathy and two had evidence of concomitant myasthenia gravis by electrodecrement. Two muscle biopsies revealed myositis with inflammatory T-cell infiltrate. 6 had positive anti-striated muscle antibody titers, 9/14 had concomitant myocarditis, 2 had hepatitis, 2 had pneumonitis and 1 had thyroiditis. All received high dose steroids, 11 received plasma exchange, 4 received rituximab, 4 received tacrolimus and 2 received tocilizumab. 7/14 patients died (50%). Mean time from initial neurology consultation for symptoms to death was 6.46 months (range .3-24). 5 patients had documented clinical stabilization or mild improvement on post-discharge follow-up. CONCLUSIONS While ptosis in patients receiving CPI can initially suggest myasthenia gravis, in patients with rapid onset and ultimately fixed deficits there should be a high index of suspicion for immunotherapy related restricted localized myositis. Myositis may coincide with other toxicities, such as myocarditis and pneumonitis, and can be fatal despite aggressive treatment. Deficits persist on post-discharge follow-up, suggesting protracted recovery for patients who survive.

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Striated Muscle Disorder (Myasthenia Gravis)

Neuropsychiatric Features of Medical Disorders ◽

10.1007/978-1-4684-3920-5_10 ◽

1981 ◽

pp. 221-229

Author(s):

James W. Jefferson ◽

John R. Marshall

Keyword(s):

Myasthenia Gravis ◽

Striated Muscle ◽

Muscle Disorder

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MYASTHENIA GRAVIS IMMUNOLOGICAL RELATIONSHIP BETWEEN STRIATED MUSCLE AND THYMUS

The Lancet ◽

10.1016/s0140-6736(66)92356-7 ◽

1966 ◽

Vol 287 (7428) ◽

pp. 57-60 ◽

Cited By ~ 78

Author(s):

HugoW.R. Van Der Geld ◽

ArthurJ.L. Strauss

Keyword(s):

Myasthenia Gravis ◽

Striated Muscle ◽

Immunological Relationship

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A case of late-onset, thymoma-associated myasthenia gravis with ryanodine receptor and titin antibodies and concomitant granulomatous myositis

BMC Neurology ◽

10.1186/s12883-016-0697-x ◽

2016 ◽

Vol 16 (1) ◽

Cited By ~ 5

Author(s):

M. I. Stefanou ◽

L. Komorowski ◽

S. Kade ◽

A. Bornemann ◽

U. Ziemann ◽

...

Keyword(s):

Myasthenia Gravis ◽

Ryanodine Receptor ◽

Late Onset ◽

Granulomatous Myositis ◽

Titin Antibodies

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Granulomatous Myositis Associated with Myasthenia Gravis: A Rare Case

Cureus ◽

10.7759/cureus.5090 ◽

2019 ◽

Author(s):

Shumaila M Iqbal ◽

Linda Burns ◽

Cassandra Zhi

Keyword(s):

Myasthenia Gravis ◽

Rare Case ◽

Granulomatous Myositis

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Myasthenia gravis and thymoma: evaluation of 41 patients

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x1999000100002 ◽

1999 ◽

Vol 57 (1) ◽

pp. 6-13 ◽

Cited By ~ 6

Author(s):

JOSÉ LAMARTINE DE ASSIS ◽

ANTONIO ALBERTO ZAMBON ◽

PATRICIA S. SOUZA ◽

PAULO EURIPEDES MARCHIORI

Keyword(s):

Myasthenia Gravis ◽

Striated Muscle ◽

Clinical Laboratory ◽

Anterior Mediastinum ◽

Clinical Findings ◽

Malignant Thymoma ◽

Results Of Treatment ◽

Clinical Investigations ◽

Immunological Tests ◽

And Control

We evaluated the epidemiological, clinical, laboratory and therapeutical aspects of 41 patients with thymomatous myasthenia gravis. Thirty five patients (85.36%) were submitted to thymectomy. Follow-up ranged from two to 18 years. Diagnosis of thymoma was based upon clinical investigations and CT scan of the anterior mediastinum and in 11 patients supported by immunological tests of anti-striated muscle antibodies with a positive result in more than 80% of cases. Histopathologic examination of all thymomectomized patients confirmed the diagnosis of thymoma. There was a significant predominance of benign over malignant thymoma. Occurred higher prevalence of male patients and of patients over 40 years of age. The therapeutical strategy to control myasthenic clinical findings was the same as that for non-thymomatous myasthenia gravis. The corticosteroids associated to cytotoxic drugs were less often used. Radiotherapy of the anterior mediastinum was more often used in patients having invasive tumors submitted to surgery or not. With regard to survival and control of myasthenia gravis, especially in younger patients and in those submitted to early surgery, results of treatment were surprisingly favorable.

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