Table 1 Summary of clinical features and disease associations.
Total | Children | Adults | |||
---|---|---|---|---|---|
AChR Ab‐ positive* | AChR Ab‐negative* | AChR Ab‐positive* | AChR Ab‐negative* | ||
Total | 127 | 70 | 127 | 64 | |
F:M | 76:51 | 29:41 | 76:51 | 34:30 | |
Maximum MGFA grade, n | |||||
1 | 227 | 103 | 54 | 31 | 39 |
2a | 50 | 11 | 10 | 19 | 10 |
2b | 53 | 10 | 2 | 30 | 11 |
3a | 5 | 0 | 1 | 3 | 1 |
3b | 34 | 3 | 2 | 26 | 3 |
4a | 4 | 0 | 1 | 3 | 0 |
4b | 6 | 0 | 0 | 6 | 0 |
5 | 9 | 0 | 0 | 9 | 0 |
Thymic pathology (MRI), n | |||||
Normal† | 98 | 52 | 63 | 48 | |
Thymitis | 26 | 18 | 29 | 12 | |
Thymoma | 3 | 0 | 35 | 4 | |
Hyperthyroidism | 16 | 5 | 16 | 17 |
Ab, antibody; AChR, acetylcholine receptor; F, female; M, male; MGFA, Myasthenia Gravis Foundation of America.
*Most of the AChR antibodies were not measured at the time of maximum disease severity.
†Normal refers to normal for age at the time of MRI; this would include adults with thymic atrophy.