Autoantibodies against the acetylcholine receptor (AChR) in the neuromuscular endplate generate blockage of the neurotransmitter acetylcholine binding to the receptors on the muscular surface. This may lead to the autoimmune disease Myasthenia Gravis (MG). Demonstration of the autoantibodies is used in the diagnosis of MG, and for the follow-up of the severity of the disease.
Analysis is performed in a serum sample from patients by use of a 125I-radioreceptor-assay (ACHRAB®-RIA assay) kit. The analysis is performed in Neuroimmunology Laboratory once a week.
Results are given as a concentration (nmol/L) of antibodies to sAChR. If the sample is positive with a high concentration at the initial screening, it is reanalysed the following week in a series of dilution for making a precise result.
The results should be interpreted as followed:
Negative result 0–0.2 nmol/l
Uncertain result 0.3–0.4 nmol/l
Positive result >0.5 nmol/l
In case of an uncertain result, it may be suggested to analyse a new sample after 2-3 months to evaluate if it has changed to negative or positive.
The result of the analysis is sent to LABKAII/sundhedsplatform for hospitals in Region H and by ordinary mail to other hospitals as soon as possible after analysis.