INDIVIDUAL TEST 079
Acetylcholine Receptor Antibodies
Indication
Suspicion of Myasthenia Gravis (MG) and thymoma
Sample material
Serum
- Minim. volume: 0,5 mL
Transport
- Within Sweden: room temperature
- International: cold
Method
RIA
Reference interval
<0.25 nmol/L negative, 0.25-0.40 nmol/L borderline
Result
Results are reported as negative, borderline or positive with a value.
Interpretation
Antibodies against ACh-R have high diagnostic specificity for Myastenia Gravis (MG) and are found in approximately 85% of cases with a generalized disease and in about 50% of those with ocular symptoms only. The antibody level is usually higher in early onset MG than in late onset MG. The antibody levels usually decrease with treatment.
The antibody level correlates poorly with the severity of the disease and low levels can be seen in pronounced symptoms. In case of negative results, it is recommended to supplement with analysis of antibodies against muscle-specific kinase (anti-MuSK) which is detected in 5-40% of MG patients negative for antibodies against ACh-R. Clinically, it cannot be distinguished between MG positive for antibodies against ACh-R or MuSK.
References
- Pirskanen-Matell R et al. Lakartidningen. 2000. Myasthenia gravis--en autoimmun neuromuskulär sjukdom [Myasthenia gravis--an autoimmune neuromuscular disease]. PMID: 11107745
- Ohta K et al. Autoimmunity. 2003. Frequency of anti-AChR epsilon subunit-specific antibodies in MG. PMID: 12911281
- Matthews I et al. Clin Chim Acta. 2004. Muscle-specific receptor tyrosine kinase autoantibodies--a new immunoprecipitation assay. PMID: 15369741
- Beeson D et al. Neurology. 1996. A transfected human muscle cell line expressing the adult subtype of the human muscle acetylcholine receptor for diagnostic assays in myasthenia gravis. PMID: 8960744
- Narayanaswami P et al. Neurology. 2021. International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update. PMID: 33144515
Last updated: 2025-10-09
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ENSKILD ANALYS 079
Acetylkolinreceptor-antikroppar
Indikation
Misstanke om myastenia gravis (MG) och tymom
Provmaterial
Serum
- Minim. volym: 0,5 mL
Transport
- Inom Sverige: rumstemperatur
- Internationellt: kylt
Metod
RIA
Referensintervall
<0,25 nmol/L negativt, 0.25-0.40 nmol/L gränsvärde
Resultat
Resultat anges som negativt, gränsvärde eller positivt med värde.
Tolkning
Antikroppar mot ACh-R har hög diagnostisk specificitet för Myastenia Gravis (MG) och påvisas i ca 85% av fallen med generaliserad sjukdom och hos ca 50% vid enbart okulära symtom. Vanligtvis påvisas högre nivåer hos ”early onset MG” jämfört med ”late onset MG”. Antikroppsnivån sjunker vanligtvis efter insatt behandling.
Antikroppsnivån korrelerar dåligt till sjukdomens allvarlighetsgrad och låga nivåer kan ses vid uttalade symtom. Vid negativt resultat rekommenderas komplettering med analys av antikroppar mot muskelspecifikt kinas (anti-MuSK) som kan påvisas i 5-40% av MG som är negativa avseende antikroppar mot ACh-R. Kliniskt kan MG som är positiv för antikroppar mot ACh-R eller MuSK inte särskiljas.
Referenser
- Pirskanen-Matell R et al. Lakartidningen. 2000. Myasthenia gravis--en autoimmun neuromuskulär sjukdom [Myasthenia gravis--an autoimmune neuromuscular disease]. PMID: 11107745
- Ohta K et al. Autoimmunity. 2003. Frequency of anti-AChR epsilon subunit-specific antibodies in MG. PMID: 12911281
- Matthews I et al. Clin Chim Acta. 2004. Muscle-specific receptor tyrosine kinase autoantibodies--a new immunoprecipitation assay. PMID: 15369741
- Beeson D et al. Neurology. 1996. A transfected human muscle cell line expressing the adult subtype of the human muscle acetylcholine receptor for diagnostic assays in myasthenia gravis. PMID: 8960744
- Narayanaswami P et al. Neurology. 2021. International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update. PMID: 33144515
Senast uppdaterat: 2025-10-09