Science News: Anti-titin Antibody Is Associated With More Frequent Hospitalization to Manage Thymoma-Associated Myasthenia Gravis

Submitted by: Nakul Katyal MD
Edited by: Eman Tawfik, MD

Kim KH, Kim SW, Cho J, Chung HY, Shin HY. Anti-titin antibody is associated with more frequent hospitalization to manage thymoma-associated myasthenia gravis. Front Neurol. 2022;13:978997. Published 2022 Oct 5. doi:10.3389/fneur.2022.978997

Summary: Anti-titin antibodies are anti-striational antibodies associated with thymoma-associated myasthenia gravis (MG). Anti-titin antibodies have been previously linked to severity of MG, but its relation to clinical worsening is not clear. Thus, the authors in this study aimed to evaluate whether the patients with anti-titin antibody are more frequently hospitalized to manage thymoma-associated MG than those patients without anti-titin antibody.

Patients with thymoma-associated MG who were tested for anti-titin antibody were retrospectively included. Parameters including disease severity, treatments, MG-related annual hospitalization rate, and emergency room visit rate were compared between the patients with anti-titin antibody and those without anti-titin antibody.

Thirty-one (48.4%) of the 64 included patients were positive for anti-titin antibody (titin+ group) and 33 (51.6%) patients were negative (titin- group). A total of 92 hospitalizations and 52 ER visits were observed during the study period. Main cause of MG-related admission was symptom aggravation (97.8%), followed by management of medication toxicity (2.2%), while the main cause of MG-related ER visit was dyspnea or chest discomfort (61.5%), followed by limb weakness (19.2%) and bulbar symptoms (9.6%).

The annual rate of MG-related hospitalization and ER visit were significantly higher in the titin positive group [0.2 (0.1-0.6) and 0.1 (0-0.2) per year, respectively] than those in the titin negative group [0 (0-0.2) and 0 (0-0) per year, p = 0.004 and p = 0.006, respectively]. Positive anti-titin antibody was significantly associated with multiple admissions [odds ratio (OR) 4.11, 95% CI 1.05-16.03] compared to the titin negative group.

Comments:
Although the association of anti-titin antibody and thymoma is well reported, controversy remains in the association between the presence of anti-titin antibody and the severity of MG. In this study, the authors observed that the presence of anti-titin antibody is associated with more frequent hospitalization and ER visits. Thus serological testing of anti-titin antibody can be utilized as a clinical indicator of disease relapse. However, given the study limitations which include the retrospective nature and the non-uniformity of timing of antibody testing, further studies are required to elucidate a causal relationship between the anti-titin antibody positivity and hospitalization associated with MG.