New autoantibodies diagnostic test in Myasthenia Gravis based on a cell-free fluorescent microparticle system

Abstract

Introduction: A new diagnostic test for the detection of autoantibodies for myasthenia gravis was developed. The new cell-free test is relatively simple and less time- and material-consuming than the standard radioimmunoassay-based methodologies in current clinical practice.
Materials and methods: The test involves the use of polystyrene microbeads coated with the nicotinic acetylcholine receptor protein (two different sources of the receptor were tested), specific labeling of the protein with high-affinity fluorescent ligands (AlexaFluor-α-bungarotoxin or polyclonal anti-receptor antibodies from sera of already diagnosed patients, followed by secondary fluorescent-labeled antibodies), and detection by fluorescence flow cytometry.
Results: mean fluorescence intensity for positive sera versus a pool of human normal sera: showed statistically significant differences for the two receptor´s source types used.
Conclusion: The two different approaches tested were successful for the detection of autoantibodies in sera from patients with myasthenia gravis. The new test has the potentiality to distinguish between different autoantibody isoforms and subtypes, and the results may be correlated with the severity of myasthenia. The test may be eventually applied to predict the clinical evolution of this pathology.