Abstract
Objectives Intravenous immunoglobulin (IVIg) and plasma exchange (Plex) are used to treat exacerbations of myasthenia gravis (MG) in inpatients. There is limited evidence of superiority of one modality. We aimed to compare the time to improvement in disease severity and duration of improvement between patients receiving IVIg or Plex for an exacerbation of MG.
Methods We retrospectively identified patients admitted with an exacerbation of MG over a 10-year period. We measured disease severity by the Myasthenia Gravis Foundation of America (MGFA) clinical classification and defined improvement as an increase in 1 Class of MGFA. We calculated the time to improvement from the start of treatment.
Results We identified 31 patients (22 females; median age 62.5 years) with generalised MG who had 48 admissions. 38 patients received IVIg first-line and 10 received Plex; 7 patients received both. 2 admissions were for ocular weakness (Class 1 in MGFA), mild weakness: 29 (Class 2a/2b), moderate weakness: 16 (Class 3a/3b), severe weakness: 5 (Class 4a/4b), intubated: 2 patients (Class 5). There was no significant difference in number of days to improvement with either treatment (median for both groups 3.0 days, p >0.05). Median length of stay in hospital was 7.5 days. 9/19 patients treated with IVIg and 5/9 patients treated with Plex and inpatient at day 7 had persistent improvement in MGFA Class.
Conclusion Onset of improvement in disease severity and stability at day 7 do not differ significantly in patients treated with IVIg or Plex for an acute exacerbation of myasthenia gravis.
