A study published in Neurology has discovered a way to improve autoantibody testing in myasthenia gravis (MG) patients. An issue that physicians and patients face is false-positive results for neuromuscular or autoimmune disorders; many MG patients are often misdiagnosed. This study aimed to fix the problem by improving autoantibody testing while maintaining sensitivity.
About Myasthenia Gravis
Myasthenia gravis is an autoimmune, neuromuscular disorder that is characterized by weakness and fatigue in the voluntary muscles that worsens with physical activity. In affected individuals, the body mistakenly attacks itself, specifically the proteins that are needed for communication between the nerves and muscle cells. Although there is no cure, doctors can treat MG with steroids, surgery to remove the thymus gland, and plasmapheresis. Other therapies may be necessary to manage symptoms as well.
Common symptoms of MG include:
- Drooping eyelids
- Issues with chewing and swallowing
- A change in gait
- Weakness and fatigue in the neck and limbs
- Double vision
- Slurred speech
About the Study
Titled “Improving Accuracy of Myasthenia Gravis Autoantibody Testing by Reflex Algorithm,” this study was intended to improve autoantibody testing for MG patients. To do so, researchers reviewed four years worth of MG serologic tests with confirmatory or refuting clinical–electrodiagnostic (EDX) testing and cancer evaluations. Every patient included in the study had received striational (STR), acetylcholine receptor–binding (AChR-Bi), and modulating (AChR-Mo) autoantibody testing.
In terms of results, 133 of the 433 samples met the criteria for myasthenia gravis. Looking further into the samples, there were 31 false positives, making the specificity of the testing 90%. Researchers found that the specificity could be improved to 95% if modulating autoantibody testing was used after AChR-Bi came back positive. This method also allowed for 90% sensitivity.
Cancer evaluations were also examined, and researchers found that CT scans revealed thymomas in 16 patients. Follow-up data revealed that subsequent cancers were diagnosed in 22 other patients. Connecting this to autoantibody testing, data showed that higher levels of autoantibodies were not associated with any cancers.
This research will allow for a better diagnostic process for MG patients, something that is currently needed.
