Identification of Important Biomarkers Aid Diagnosis of Myasthenia Gravis
MYASTHENIA gravis (MG) is an autoimmune condition for which diagnosis is notably difficult as the symptoms tend to imitate those of other conditions, such as stroke. The symptoms of this chronic disease include weakness and rapid fatigue of voluntary muscles. It is currently diagnosed via the detection of acetylcholine and receptor muscle-specific kinase antibodies, and treatment aims to increase levels of acetylcholine in the blood and suppress the immune system.
Previous studies have shown that disease progression is not indicated in the current diagnosis of MG. A new study co-led by Dr Zaeem Siddiqi, Division of Neurology, University of Alberta, Alberta, Canada, and, Dr Derrick Blackmore, Autonomic Lab, University of Alberta, Alberta, Canada, identified blood serum biomarkers which allowed for effective diagnosis and, significantly, the extent of disease severity in MG. “Right now, we don’t have the ability to manage [MG] in a more specific way; we treat all patients the same,” said Dr Siddiqi.
The study recruited three participants groups: individuals with MG, rheumatoid arthritis (used as a reference group), and healthy control participants. The rheumatoid arthritis cohort all exhibited symptoms with great similarity to those of MG, and the participants were close in age and sex. Serum extractions were analysed and filtered to remove shared markers, which allowed 12 unique biomarkers to remain. There was a marked difference in the biomarkers between the groups and distinct variability between each disease stage which allows for analysis of disease severity. In patients with MG, upregulation of α-ketobutyric acid, a key metabolic pathway regulator, was indicative of increased metabolic activity in the cells of people with MG.
The authors noted some limitations: the metabolic profile of some patients may have been altered due to drug therapy before the trial; additionally, fasting prior to the study was not a required condition, both factors could have led to resultant false positives. Despite the limitations, the findings allowed efficient identification of metabolites in individuals showing symptoms of MG urging quicker diagnosis of the disease by clinicians. “Now we have a unique fingerprint or map of metabolites that can easily separate healthy individuals from those with [MG] and a path to the discovery of more accurate and specific treatments,” reflected Dr Siddiqi.