Low-dose versus standard-dose intravenous immunoglobulin in generalized myasthenia gravis: a prospective single-center cohort study.

Background: Generalized myasthenia gravis (gMG) is commonly treated with high-dose intravenous immunoglobulin (IVIG), typically at cumulative doses near 2 g/kg, during clinical worsening. However, the minimal effective IVIG exposure remains uncertain. Methods: In this prospective single-center cohort study, we enrolled 34 adults with AChR-positive gMG who received either low-dose IVIG (target ≤0.2 g/kg/day; Results: Both regimens were associated with clinically meaningful improvement in MG-ADL and QMG through week 12, and no statistically significant between-group differences were detected at any follow-up visit. Most patients received 5 infusion days. After weight-based conversion, the low-dose group clustered around a cumulative exposure of approximately 1.0 g/kg, whereas the standard-dose group clustered around approximately 2.0 g/kg. Acute exacerbation was the most common indication in both groups, whereas maintenance therapy was more frequent in the standard-dose cohort. Prednisone requirements did not decline over 12 weeks in either group. Conclusion: In this prospective observational cohort, low-dose IVIG was associated with short-term clinical improvement comparable to that observed with standard-dose IVIG, without a clear steroid-sparing signal. These findings should be interpreted cautiously given the small sample size, baseline imbalance, and non-randomized design.