To report a rare case of a patient with concurrent stiff-person syndrome (SPS) and myasthenia gravis (MG) associated with thymoma and evaluate the efficacy of efgartigimod as a treatment for refractory MG.
Approach:
Patient Presentation: A 43-year-old woman presented with progressive limb stiffness and was diagnosed with SPS based on positive anti-GAD antibodies.
Diagnosis and Treatment History: After initial improvement with immunotherapy, she developed MG associated with type B2 thymoma four years later, requiring thymectomy and radiotherapy.
Treatment Challenges: Conventional treatments for MG, including plasma exchange and rituximab, were ineffective, leading to a myasthenic crisis.
Efgartigimod Treatment: Efgartigimod therapy resulted in marked recovery of respiratory and motor function, with no recurrence of SPS or MG symptoms during follow-up.
Key Findings:
The coexistence of SPS and MG is extremely rare, with fewer than 20 cases reported.
Thymoma has been identified in a significant number of patients with overlapping autoimmune disorders.
Efgartigimod therapy resulted in marked recovery of respiratory and motor function in a patient with refractory thymoma-associated MG.
Interpretation:
This case highlights the complex association among SPS, MG, and thymoma, suggesting a potential role of thymoma in the development of overlapping autoimmune conditions.
Limitations:
The rarity of the condition limits the generalizability of the findings.
The long-term effects of efgartigimod in this specific context remain to be established.
Conclusion:
Efgartigimod may represent a potential therapeutic option for patients with refractory thymoma-associated MG and overlapping SPS, but further studies are needed.
