Novel modulation of T effector memory cells-expressing CD45RA by prednisone in inoperable advanced type B thymoma patients

Due to the covert onset of thymoma, nearly 30% of patients are diagnosed at stage III or IV, losing the opportunity for surgical treatment. We have initiated the application of prednisone in treating refractory thymoma and explored biomarkers to identify potential cases that might benefit from prednisone treatment. In a study involving 96 patients with thymoma, we confirmed a significant tumor shrinkage with prednisone acetate treatment. A reduced diameter ratio indicated that type B1 and B2 thymomas exhibited the most obvious response to prednisone acetate, especially type B2 thymoma. However, the reduced diameter ratio was < 30% in type A, AB, and B3 thymomas. Immunofluorescence and flow cytometry of tumor tissues indicated that TEMRA (T Effector Memory-Expressing CD45RA) cells primarily exist in type B thymoma. However, the percentage of interleukin-8 + TEMRA cells decreased only in B1 and B2 thymoma tissues after prednisone acetate treatment. These findings are particularly significant for patients with type B thymoma with stage III or IV.