Abstract: Objective  To explore the significance of AchR antibody， Titin antibody and MuSK antibody in myasthenia gravis patients combined with thymic lesion. Methods  A total 80 cases of myasthenia gravis patients treated in our hospital were selected. They were divided into thymic lesion group(n=48) and nothymic lesion group(n=32). Another 80 cases of healthy individuals were selected as control group. The positive rates of AchR antibody， Titin antibody and MuSK antibody were compared among three groups and different Osserman types. Results  The positive rates of AchR antibody and Titin antibody of myasthenia gravis group(76.3%，52.5%) were higher than those of control group(11.3%，5.0%)(P<0.05). The positive rates of MuSK antibody of two groups were 0， but the level of myasthenia gravis group was higher than that of control (P<0.05). The detection sensitivity of myasthenia gravis could be improved using AchR antibody and Titin antibody. The positive rates of AchR antibody and Titin antibody of thymic lesion group were higher than those of nothymic lesion group(P<0.05). The positive rates of AchR antibody and Titin antibody in generalized myasthenia gravis patients were higher than those in ocular myopathy myasthenia gravis patients(P<0.05). Conclusion  The positive rates of AchR antibody and Titin antibody were related to the illness of myasthenia gravis. It can improve the detection sensitivity of myasthenia gravis using AchR antibody and Titin antibody.

Key words: myasthenia gravis, thymus, acetylcholine receptor, muscle associated protein, muscle specific tyrosine kinase