Table 1.
Comparison of episodes of myasthenic crisis with MuSK- and AChR-ABs
| Myasthenic crisis | ACh-Rec.-positive (n = 161) | MuSK—positive (n = 19) | p value | Odds ratio |
|---|---|---|---|---|
| Age | 66.8 ± 15.6 (14 – 88) | 66.0 ± 17.7 (28 – 82) | 0.83 | |
| Age ≤ 50 years | 22 (13.7%) | 4 (21.1%) | 0.49 | 1.69 |
| Male/female | 99/62 | 7/12 | 0.05 | 2.74 |
| Pulmonary disease | 35 (21.7%) | 9 (47.4%) | 0.02 | 3.24 |
| Heart disease | 66 (41%) | 8 (42.1%) | 1.00 | 1.05 |
| Diabetes mellitus | 48 (29.8%) | 2 (10.5%) | 0.10 | 0.28 |
| Tumour (other than Thymoma) | 23 (14.3%) | 6 (31.6%) | 0.09 | 2.78 |
| Dialysis | 2 (1.2%) | 0 (0%) | 1.00 | 1.64 |
| Smoker | 12 (7.5%) | 1 (5.3%) | 1.00 | 0.69 |
| Alcohol addicted | 5 (3.1%) | 0 (0%) | 1.00 | 0.73 |
| ≥ 3 diseases (Kidney, Heart, Lung, Diabetes, Tumour) | 11 (6.8%) | 5 (26.3%) | 0.016 | 4.87 |
| Myasthenia gravis | ||||
| Early onset | 22 (13.9%; 3 unknown) | 4 (22.2%; 1 unknown) | 0.31 | 1.75 |
| Late onset | 136 (86.1%) | 14 (77.8%) | 0.31 | 0.57 |
| Paraneoplastic MG (Thymoma) | 58 (36%) | 4 (21.1%) | 0.31 | 0.47 |
| Thymus hyperplasia | 5 (3.1%) | 0 | 1.00 | 0.73 |
| MGFA-classification before crisis | ||||
| First manifestation of MG | 35 (21.7%) | 3 (15.8%) | 0.77 | 0.68 |
| Class I | 10 (6.2%) | 0 (0%) | 0.60 | 0.37 |
| Class II | 42 (26.1%) | 4 (21.1%) | 0.78 | 0.76 |
| Class III | 40 (24.8%) | 5 (26.3%) | 1.00 | 1.08 |
| Class IV | 20 (12.4%) | 6 (31.6%) | 0.04 | 3.25 |
| Unknown | 14 (8.7%) | 1 (5.3%) | ||
| Status before crisis | ||||
| Independent at home | 71 (44.1%) | 6 (31.6%) | 0.34 | 0.58 |
| At home dependent on help | 19 (11.8%) | 3 (15.8%) | 0.71 | 1.41 |
| In a care facility or hospital | 50 (31.1%) | 9 (47.4%) | 0.20 | 2.00 |
| Unknown | 21 (13.0%) | 1 (5.3%) | ||
| Cause of crisis | ||||
| Infection | 85 (52.8%) | 10 (52.6%) | ||
| First episode | 34 (21.1%) | 3 (15.8%) | ||
| Poor treatment compliance | 9 (5.6%) | 1 (5.3%) | n.s | |
| Intake of contraindicated medication | 2 (1.2%) | 0 (0%) | ||
| Idiopathic/unknown | 33 (20.5%) | 5 (26.3%) | ||
| Therapy | ||||
| IVIG | 92 (57.5%; 1 unknown) | 9 (47.4%) | 0.47 | 0.68 |
| Plasma exchange/immunoadsorption | 72 (44.7%) | 13 (68.4%) | 0.056 | 2.68 |
| PE or IA as first-line therapy | 49 (30.4%) | 10 (52.6%) | 0.07 | 2.56 |
| IVIG + plasma exchange or Immunoadsorption | 25 (15.6%) | 5 (26.3%) | 0.32 | 1.94 |
| Continuous pyridostigmine infusion | 63 (39.1%) | 7 (36.8%) | 1.00 | 0.91 |
| Continuous potassium infusion | 66 (41%) | 6 (31.6%) | 0.47 | 0.66 |
| Complications | ||||
| CPR | 16 (9.9%) | 2 (10.5%) | 1.00 | 1.06 |
| Pneumonia | 86 (53.4%) | 13 (68.4%) | 0.23 | 1.89 |
| Sepsis | 27 (16.8%) | 6 (31.6%) | 0.12 | 2.29 |
| Outcome | ||||
| Days of mechanical ventilation at ICU | 17.4 ± 18 (1–119) | 43.0 ± 53.1 (4–219) | < 0.0001 | |
| Days at ICU | 21.2 ± 19.7 (1–135) | 45.3 ± 49.5 (6–219) | < 0.0001 | |
| Days in hospital | 28.8 ± 20.9 (2–144) | 55.9 ± 47.6 (11–219) | < 0.0001 | |
| In-hospital mortality | 16 (9.9%) | 3 (15.8%) | 0.43 | 1.70 |
Age, “Days of mechanical ventilation at ICU”, “Days at ICU” and “Days in hospital” are depicted as mean ± Standard Deviation and range, other parameters are total number with percentage in brackets. MGFA Myasthenia Gravis Foundation of America, MG Myasthenia Gravis, IVIG intravenous immunoglobulin, PE plasma exchange, IA immunoadsorption, CPR Cardio Pulmonal Resuscitation, n.s. not significant. T test was used for statistic analysis of age-differences and for comparison of “Days of mechanical ventilation at ICU”, “Days at ICU” and “Days in hospital”. For other parameters, Fisher’s exact test with odds ratio was used
Significant result (p ≤ 0.05) are shown in bold letters