Clinical Characteristics of Myasthenia Gravis Patients with Coexistence of AChR and Titin Antibodies

Siqi 王思奇 Wang¹Difang Shi²Shanshan Wu¹Qijie Zhang³Weiwei Xiao⁴Fang Qian⁵Yan Zheng⁵Jianjian Bao⁵Jia Liu⁵Kang Du^5*Xujun Chu^6*

• ¹Department of Clinical Pharmacy, Kunming Medical University Affiliated Qujing Hospital, Qujing, China
• ²Department of Thoracic Surgery I, Yunnan Cancer Hospital Third Department of Breast Surgery, Kunming, China
• ³Second People's Hospital of Qujing City, Qujing, China
• ⁴Department of Neurolog, Kunming Medical University Affiliated Qujing Hospital, Qujing, China
• ⁵Department of Neurology, Kunming Medical University Affiliated Qujing Hospital, Qujing, China
• ⁶Department of Neurology, Shandong First Medical University, Jinan, China

Objective: This study aimed to investigate the clinical characteristics of patients with myasthenia gravis (MG) who are double-seropositive for acetylcholine receptor antibodies (AChR-Ab⁺) and titin antibodies (Titin-Ab⁺). Methods: A retrospective analysis was conducted on MG patients hospitalized in the Department of Neurology between March 2020 and June 2024. Patients were categorized into two groups based on antibody profiles: those with AChR antibody positivity alone and those with dual positivity for AChR and titin antibodies. Clinical features, MG classification, and treatment outcomes were compared between the two groups. Results: A total of 35 MG patients were included, comprising 18 with single AChR-Ab⁺ and 17 with AChR-Ab ⁺ /Titin-Ab⁺ . The dual antibody-positive group showed a significantly higher proportion of patients with MGFA classification above Class II (47. 1%) and a higher rate of thyroid dysfunction (50%) compared to the single antibody-positive group (p = 0. 001). The median age of onset in the dual antibody-positive group was older than that in the single antibody-positive group (67. 0 years vs. 58. 5 years), although this difference was not statistically significant (p > 0. 05). No significant differences were observed between the two groups in terms of gender, initial symptoms, clinical manifestations, thymic hyperplasia, proportion of thymoma, treatment regimens, or therapeutic outcomes (all p > 0. 05). Conclusion: This study provides the first systematic characterization of the clinical profile of AChR-Ab⁺ /Titin-Ab⁺ myasthenia gravis patients in Southwest China. Our findings indicate that dual antibody-positive MG patients are more prone to generalized disease involvement and have a higher susceptibility to thyroid dysfunction.