Table 1.
Preoperative characteristics of the study population.
| Variables | All patients (n = 47) |
Study groups |
p
value |
|
|---|---|---|---|---|
| IVIg (n = 25) | Placebo (n = 22) | |||
| Sex, n (%): | 0.718 | |||
| Men | 19 (40.4) | 9 (36) | 10 (45.4) | |
| Women | 28 (59.6) | 16 (64) | 12 (54.5) | |
| Age, years | 58.6 (16.2) | 61.1 (15.3) | 55.7 (17.0) | 0.357 |
| BMI, kg/m2 | 27.8 (4.8) | 27.4 (4.7) | 28.2 (5.0) | 0.898 |
| Age at clinical onset, years | 52.4 (18.6) | 54.3 (17.5) | 50.2 (20.0) | 0.609 |
| Duration of MG, years | 6.2 (8.0) | 6.8 (7.9) | 5.5 (8.3) | 0.639 |
| MGFA class at clinical onset | 0.090 | |||
| I | 2 | 0 | 2 | |
| IIA | 17 | 11 | 6 | |
| IIB | 3 | 3 | 0 | |
| IIIA | 14 | 8 | 6 | |
| IIIB | 9 | 3 | 6 | |
| IVB | 2 | 0 | 2 | |
| MGFA-PIS category | 0.200 | |||
| MM-1 | 5 | 4 | 1 | |
| MM-2 | 2 | 2 | 0 | |
| MM-3 | 40 | 19 | 21 | |
| Patients with prior history of: | ||||
| Thymoma | 13 (27.7) | 6 (24) | 7 (31.8) | 0.786 |
| Surgery with general anaesthesia | 26 (55.3) | 13 (52) | 13 (59.1) | 0.846 |
| Myasthenic crisis | 10 (21.3) | 5 (20) | 5 (22.7) | 1.000 |
| Bulbar symptoms, n (%) | 14 (29.8) | 6 (24) | 8 (36.4) | 0.545 |
| Bulbar score | 0.3 (0.7) | 0.1 (0.3) | 0.4 (1.0) | 0.296 |
| Anti-AChR level, nmol/l | 12.9 (8.3) | 14.4 (8.0) | 11.3 (8.5) | 0.045 |
| Pulmonary function tests: | ||||
| FVC, % | 84.4 (14.9) | 85.1 (15.4) | 83.7 (14.6) | 0.912 |
| FEV1, % predicted | 90.1 (17.9) | 91.0 (18.9) | 89.0 (17.0) | 0.886 |
| Peak flow | 396.4 (142.1) | 359.2 (135.9) | 438.6 (140.2) | 0.796 |
| QMG score | 6.3 (3.7) | 6.1 (3.8) | 6.6 (3.5) | 0.653 |
| MGQoL score | 13.7 (14.7) | 11.6 (13.6) | 16.0 (15.8) | 0.472 |
| Pyridostigmine treatment, n (%) | 42 (89.4) | 21 (84.0) | 21 (95.5) | 0.352 |
| Pyridostigmine, mg | 178.1 (35.4) | 180.0 (30.0) | 175.7 (43.9) | 1.000 |
| Immunosuppressants, mg/day: | ||||
| Prednisone (n = 47) | 11.8 (20.6) | 13.5 (21.7) | 9.9 (19.5) | 0.600 |
| Azathioprine (n = 4) | 62.5 (25.0) | 62.5 (25.0) | 0 | 0.112 |
| Tacrolimus (n = 26) | 3.5 (1.3) | 3.2 (1.2) | 3.9 (1.4) | 0.229 |
| Mycophenolate mofetil (n = 2) | 1250 (1061) | 500 | 2000 | 1.000 |
Data as mean ± SD unless otherwise stated.
AChR, acetylcholine receptor; BMI, body mass index; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 s; IVIg, intravenous immunoglobulin; MG, myasthenia gravis; MGFA-PIS, Myasthenia Gravis Foundation of America Post-Intervention Status; MGQoL, MG quality-of-life questionnaire; MM, minimal manifestations; MM-1, the patient continues to receive some form of immunosuppression but no cholinesterase inhibitors or other symptomatic therapy; MM-2, the patient has received only low-dose cholinesterase inhibitors (,120 mg pyridostigmine/day) for at least 1 year; MM-3, the patient has received cholinesterase inhibitors or other symptomatic therapy and some form of immunosuppression during the past year; QMG, quantitative myasthenia gravis score; SD, standard deviation.