Clinical and economic outcomes of myasthenia gravis and myasthenic crisis when treated with PLEX and IVIG.

Introduction: Myasthenia gravis is an autoimmune disorder characterized by muscle weakness, with myasthenic crisis representing a life-threatening exacerbation requiring respiratory support. Acute treatment options include plasmapheresis (PLEX) and intravenous immunoglobulin (IVIG). Prior studies have reported mixed results regarding the relative effectiveness of these therapies, although recent evidence suggests that PLEX may provide faster and more noticeable clinical improvement. The objective of this study was to evaluate differences in clinical and economic outcomes among U.S. patients hospitalized for myasthenia gravis or crisis who received PLEX, IVIG, both, or neither treatment. Methods: Myasthenia gravis and crisis admissions from 2017 to 2022 were collected using the National Inpatient Sample. Admissions were categorized by treatment: IVIG, PLEX, both, or neither. To minimize selection bias, admissions were propensity-matched for IVIG and PLEX. Differences in mortality were evaluated using logistic regression models. Length of stay and inflation-adjusted total charge were assessed using linear regression models. Results: Most admissions received neither PLEX nor IVIG. Compared to treatment with neither, treatment with IVIG, PLEX, or both were not associated with significant differences in mortality; however, they were linked to longer hospital stays and higher total charge. A direct comparison of PLEX vs. IVIG revealed similar mortality and total charges, although length of stay was longer for PLEX. Older age was associated with increased mortality. Discussion: Although PLEX has been advocated as first-line therapy due to rapid clinical improvement, national data do not clearly indicate a superior treatment option, with similar mortality and total charges observed across therapies.