Clinical and serological study of myasthenia gravis in HuBei Province, China
- 1Department of Neurology, Tongji Hospital, Huazhong University of Science and Technology, WuHan, China
- 2Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford,UK
- Correspondence to: Professor A Vincent Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford OX3 9DS, UK; Co-corresponding author: Professor Wei Wang, Department of Neurology, Tongji Hospital, Huazhong University of Science and Technology (HUST), WuHan, China;
- Received 22 June 2006
- Accepted 23 October 2006
- Revised 13 October 2006
- Published Online First 6 November 2006
Background: Ocular and childhood myasthenia gravis (MG) cases seem relatively more common in Oriental than in Caucasian populations, but there have been no comprehensive serological studies on patients from mainland China.
Methods: 391 unselected patients with MG attending Tongji Hospital in WuHan (the largest hospital in the province of HuBei, China) were studied during a 15-month period; most had already received treatment for their condition.
Results: The male to female ratio was 0.8. 50% of the patients were children (<15 years), and age at onset showed a single peak at between 5 and 10 years of age. 64% of the children and 66% of the adults were positive for acetylcholine receptor (AChR) antibodies but the antibody titres were lower than in similar Caucasian studies, although this was partly due to the high incidence of ocular MG. Of the 43 patients with generalised MG without AChR antibodies, only 1 had muscle-specific kinase antibodies (2.5%) and 2 had voltage-gated calcium channel antibodies indicating probable Lambert–Eaton myasthenic syndrome. 75% of the children, compared with only 28% of the adults, had ocular MG. Thymoma was evident by MRI in 1.5% of children and in 20% of adults. Despite most patients having received prednisone, very few had obtained full clinical remission.
Conclusion: This study emphasises the frequency of early childhood onset with ocular symptoms and shows that many of these patients have AChR antibodies. By contrast, patients presenting in later age seem to be very uncommon in comparison with recent studies in Caucasian populations.
- AChR, acetylcholine receptor
- MG, myasthenia gravis
- MGFA, Myasthenia Gravis Foundation of America
- MuSK, muscle-specific kinase
- SNMG, seronegative myasthenia gravis
- VGCC, voltage-gated calcium channel
Published Online First 6 November 2006
Competing interests: The Department of Clinical Neurology in Oxford receives payments and royalties from AChR and MuSK antibody tests.