Does change in acetylcholine receptor antibody level correlate with clinical change in myasthenia gravis?

INTRODUCTION: The objective of this study is to determine if change in acetylcholine receptor antibody (AChR-ab) levels reflects change in clinical severity in patients with myasthenia gravis (MG). METHODS: We reviewed results from a prospective trial in MG and from all 85 patients in an MG Clinic who had AChR-ab determinations performed at least twice by the same commercial laboratory. RESULTS: Change in AChR-ab levels correlated only weakly with change in clinical severity. AChR-ab levels fell in 92% of patients who improved and in 63% who did not. A fall in AChR-ab level had a positive predictive value for clinical improvement of 83% and a negative predictive value of only 59%. CONCLUSIONS: AChR-ab levels fell in almost all patients who improved, but also in most patients who did not. Thus, we do not recommend commercially available AChR-ab levels as a biomarker of improvement in MG. However, antibody levels might be useful as a marker for inadequate immunotherapy.

Duke Scholars

Author Donald Benjamin Sanders Neurology, Neuromuscular Disease

Author Janice Munn Massey Neurology, Neuromuscular Disease

Author Vern Charles Juel Neurology, Neuromuscular Disease

Author Lisa Deneen Hobson-Webb Neurology, Neuromuscular Disease