- Comparison between AChR-positive and double-seronegative MG (excluding MuSK MG patients†).
| Variables | AChR MG (n =56, 58.9%) | SN MG (n =39, 41.1%) | Total (n=95) | P-value | ||
|---|---|---|---|---|---|---|
| n (%) | ||||||
| Gender | n (%) | |||||
| Male | 23 (24.2) | 14 (14.7) | 37 (38.9) | 0.611 | ||
| Female | 33 (34.7) | 25 (26.3) | 58 (61.1) | |||
| Onset | ||||||
| EOMG | 38 (40.0) | 31 (32.6) | 69 (72.6) | 0.211 | ||
| LOMG | 18 (16.8) | 8 (10.5) | 26 (27.3) | |||
| MG types at onset | ||||||
| Ocular | 25 (26.3) | 25 (26.3) | 50 (52.6) | 0.062 | ||
| Generalized | 31 (32.6) | 14 (14.7) | 45 (47.4) | |||
| Symptoms at onset | ||||||
| Ocular | 49 (51.6) | 33 (34.7) | 82 (86.3) | 0.687 | ||
| Fatigability | 38 (40.0) | 20 (21.1) | 58 (61.1) | 0.103 | ||
| Fluctuation | 26 (27.4) | 16 (16.8) | 42 (44.2) | 0.602 | ||
| Bulbar | 19 (20) | 7 (7.4) | 26 (27.4) | 0.086 | ||
| Facial weakness | 14 (14.7) | 4 (4.2) | 18 (18.9) | 0.071 | ||
| Respiratory symptoms/failure | 6 (6.3) | 2 (2.1) | 8 (8.4) | 0.335 | ||
| Neck weakness | 18 (18.9) | 7 (7.4) | 25 (26.3) | 0.122 | ||
| Limb weakness | 22 (23.1) | 5 (5.3) | 27 (28.4) | 0.005 | ||
| NCS (RNS) (n = 63) | ||||||
| Positive | 30 (47.6) | 14 (22.2) | 44 (68.2) | 0.007 | ||
| Negative | 6 (9.5) | 13 (20.6) | 19 (31.8) | |||
| Chest CT (n = 67) | ||||||
| Normal | 26 (47.6) | 18 (22.2) | 44 (65.7) | 0.006 | ||
| Abnormal | 21 (31.3) | 02 (3.0) | 23 (34.3) | |||
| Thymic hyperplasia | 10 (15.2) | 2 (3) | 12 (18.2) | |||
| Thymoma | 8 (12.1) | 0 | 8 (12.1) | |||
| Thymic atrophy | 3 (4.5) | 0 | 3 (4.5) | |||
| Treatment outcome(n = 55) | ||||||
| Remission | 4 (7.3) | 2 (3.6) | 6 (10.9) | |||
| Improvement | 28 (50.9) | 12 (21.8) | 40 (72.7) | 0.972 | ||
| Worsening | 6 (10.9) | 3 (5.5) | 9 (16.4) | |||
AChR - acetylcholine receptor, CT - computed tomography, EOMG - early onset myasthenia gravis (≤49 years), LOMG - late onset myasthenia gravis (> 49 years), MG - myasthenia gravis, MuSK - muscle specific tyrosine kinase, NCS - nerve conduction studies, RNS - repetitive nerve stimulation, SN - seronegative, †3 MuSK patients: 2 females and 1 male, 2 with EOMG and 1 LOMG, all generalized disease, 2 with normal CT chest, and 1 with thymic hyperplasia