PMID- 15834033
OWN - NLM
STAT- MEDLINE
DCOM- 20050531
LR  - 20181113
IS  - 0022-3050 (Print)
IS  - 1468-330X (Electronic)
IS  - 0022-3050 (Linking)
VI  - 76
IP  - 5
DP  - 2005 May
TI  - Patterns and severity of neuromuscular transmission failure in seronegative 
      myasthenia gravis.
PG  - 714-8
AB  - OBJECTIVES: To compare the clinical and electrophysiological features of 
      myasthenia gravis (MG) patients with (seropositive) or without (seronegative) 
      antibodies to acetylcholine receptor. To investigate whether antibodies to muscle 
      specific kinase (MuSK) and ryanodine receptor (RyR) are associated with 
      particular features. METHODS: Clinical profiles and single fibre electromyography 
      (SFEMG) in the extensor digitorum communis (EDC) were reviewed in consecutive 57 
      seropositive and 13 seronegative patients. Antibodies to MuSK and RyR were 
      measured by immunoassays. RESULTS: Of the 13 seronegative patients, four (31%) 
      were positive for MuSK antibodies and seven (54%) were positive for RyR 
      antibodies, including all four MuSK positive patients. Clinical features were 
      similar at presentation for seropositive and seronegative patients, but MuSK 
      positive patients frequently developed myasthenic crises. Despite the similar 
      clinical severities at the time of examination, the proportion with positive 
      jitter (93% of seropositive patients, 50% of MuSK positive patients, and 44% of 
      MuSK negative patients) and the extent of jitter (mean consecutive difference: 76 
      micros in seropositive patients, 36 micros in MuSK positive patients, and 30 
      micros in MuSK negative patients) were less in seronegative MG patients compared 
      with seropositive MG patients. CONCLUSIONS: Seronegative MG is heterogeneous with 
      respect to the presence of antibodies to MuSK. Impairment of neuromuscular 
      synaptic transmission in EDC is less marked in seronegative than seropositive MG 
      despite the similar clinical severity. This discrepancy may partly reflect the 
      distribution of affected muscles in seronegative patients, but it is possible 
      that other factors, such as impaired excitation-contraction coupling resulting 
      from RyR antibodies, contribute to the clinical phenotype.
FAU - Nemoto, Y
AU  - Nemoto Y
AD  - Department of Neurology, Chiba University School of Medicine, Chuo-ku, Chiba 
      260-8670, Japan.
FAU - Kuwabara, S
AU  - Kuwabara S
FAU - Misawa, S
AU  - Misawa S
FAU - Kawaguchi, N
AU  - Kawaguchi N
FAU - Hattori, T
AU  - Hattori T
FAU - Takamori, M
AU  - Takamori M
FAU - Vincent, A
AU  - Vincent A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Neurol Neurosurg Psychiatry
JT  - Journal of neurology, neurosurgery, and psychiatry
JID - 2985191R
RN  - 0 (Antibodies)
RN  - 0 (Receptors, Cholinergic)
RN  - 0 (Ryanodine Receptor Calcium Release Channel)
RN  - EC 2.7.10.1 (MUSK protein, human)
RN  - EC 2.7.10.1 (Receptor Protein-Tyrosine Kinases)
SB  - IM
MH  - Adult
MH  - Aged
MH  - Aged, 80 and over
MH  - Antibodies/immunology
MH  - Electromyography
MH  - Female
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Muscle, Skeletal/immunology/*innervation/*physiopathology
MH  - Myasthenia Gravis/immunology/*physiopathology
MH  - Receptor Protein-Tyrosine Kinases/immunology
MH  - Receptors, Cholinergic/immunology
MH  - Ryanodine Receptor Calcium Release Channel/immunology
MH  - Severity of Illness Index
MH  - Synaptic Transmission/*physiology
PMC - PMC1739635
EDAT- 2005/04/19 09:00
MHDA- 2005/06/01 09:00
PMCR- 2008/05/01
CRDT- 2005/04/19 09:00
PHST- 2005/04/19 09:00 [pubmed]
PHST- 2005/06/01 09:00 [medline]
PHST- 2005/04/19 09:00 [entrez]
PHST- 2008/05/01 00:00 [pmc-release]
AID - 76/5/714 [pii]
AID - 10.1136/jnnp.2004.043125 [doi]
PST - ppublish
SO  - J Neurol Neurosurg Psychiatry. 2005 May;76(5):714-8. doi: 
      10.1136/jnnp.2004.043125.