Clinical characteristics and peripheral immune profile analysis of thymoma-associated myasthenia gravis with anti-titin antibodies: a multicenter, retrospective study

Thymoma-associated myasthenia gravis (TAMG) patients with anti-titin antibodies exhibit uncertain clinical and immunological relevance. We analyzed 91 TAMG patients (40 Titin + group, 51 Titin– group) treated between 2019 and 2025. Clinical features, severity scores, and peripheral immune markers were compared, and finally tested the correlation between the latter and severity. Titin + group had higher rates of MGFA ≥ III (55.0% vs. 25.5%, p = 0.004) and elevated QMG bulbar scores [3.00 (0.75–3.00) vs. 0.00 (0.00–0.00), p = 0.002]. They also showed increased platelets (249.4 ± 62.0 vs. 224.2 ± 48.0 × 10 9 /L, p = 0.033), monocytes (0.59 ± 0.27 vs. 0.46 ± 0.23 × 10 9 /L, p = 0.018), and IL-1β [4.20 (1.85–12.06) vs. 1.13 (0.46–3.13) pg/mL, p = 0.009]. IL-6 correlated with MGFA class ( r = 0.67, p = 0.004) and QMG respiratory scores ( r = 0.70, p = 0.026); NLR with QMG ( r = 0.60, p = 0.018) and MG-ADL ( r = 0.53, p = 0.044); TNF-α ( r = 0.86, p = 0.014) and IL-8 ( r = 0.79, p = 0.036) with MG-QoL15; PLR with QMG gross motor ( r = 0.53, p = 0.041) and bulbar scores ( r = 0.58, p = 0.025); SII and IL-2 with QMG bulbar ( r = 0.53, p = 0.046) and respiratory scores ( r = 0.78, p = 0.040), respectively. Anti-titin antibodies positive TAMG is associated with more severe disease—especially bulbar involvement. NLR, PLR, IL-2, IL-6, IL-8, and TNF-α are candidate biomarkers of severity.