Table 2.
Results of secondary outcome measures
| Treatment-refractory MG (n = 14) | Treatment-responsive MG (N = 112) | p value* | |
|---|---|---|---|
| Myasthenic crisis | 2 (14.3%) | 8 (7.1%) | 0.351 |
| Severe exacerbation | 9 (64.3%) | 30 (26.8%) | 0.004‡ |
| Mortality | 2 (14.3%) | 10 (8.9%) | 0.52 |
| MGFA at last FU | < 0.000‡ | ||
| Asymptomatic | 1 (7.1%) | 77 (68.8%) | |
| 1 | 3 (21.4%) | 7 (6.3%) | |
| 2 | 6 (42.9%) | 24 (21.4%) | |
| 3 | 4 (28.6%) | 4 (3.6%) | |
| 4 | 0 | 0 | |
| 5 | 0 | 0 | |
| MGFA-PIS at last FU** | NA | ||
| CSR | 12 (10.7%) | ||
| PR | 19 (17%) | ||
| MM-0 | 0 | ||
| MM-1 | 2 (1.8%) | ||
| MM-2 | 6 (5.4%) | ||
| MM-3 | 1 (7.1%) | 38 (33.9%) | |
| Median time onset to FU | 90.5 months (IQR 104) | 70 months (IQR 67) | 0.047 |
| Median number of rescue treatments per patient with IVIG, PLEX or IA | 3 (IQR 6) | 0.5 (IQR 1) | 0.002‡ |
| Median number of different IS treatments | 3 (IQR 1) | 2 (IQR 1) | < 0.000‡ |
| Escalation IS treatment*** | 12 (85.7%) | 6 (5.4%) | < 0.000‡ |
| Side effects of IS treatment | 8 (57.1%) | 42 (37.5%) | 0.23 |
| Treatment at last FU | |||
| Pyridostigmine | 12 (85.7%) | 73 (65.2%) | 0.12 |
| IS treatment | 14 (100%) | 84 (75%) | 0.034 |
| Maintenance IVIG/PLEX/IA | 5 (35.7%) | 3 (2.7%) | < 0.000‡ |
Results of secondary outcome measures. Significance level after correction for multiple comparisons (Bonferroni correction) is P ≤ 0.004
CSR denotes complete stable remission, FU follow-up, IA immunoadsorption, IS immunosuppressive, IVIG intravenous immunoglobulins, MG myasthenia gravis, MGFA Myasthenia Gravis Foundation of America, MM minimal manifestation, NA not applicable, PIS postintervention status, PLEX plasma exchange therapy and PR pharmacologic remission
*p values were obtained with the Mann–Whitney U or Student’s t test (for continuous variables) and the Chi-squared test (for categorical variables) as appropriate
**16 patients in the treatment-responsive group did not meet the time criterion (duration of at least 1 year) of MGFA-PIS definitions
***Escalation IS treatment was defined as treatment with rituximab or cyclophosphamide
‡Statistically significant