Myasthenia gravis after allogeneic bone marrow transplantation treated with mycophenolate mofetil monitored by peripheral blood OX40⁺ CD4⁺ T cells

Abstract: A patient who developed myasthenia gravis (MG) 25 months after allogeneic bone marrow transplant was immunologically analyzed. OX40⁺CD4⁺ T cells in the peripheral blood prominently increased one month before the onset of MG. CD4/CD8 ratios, usually abnormally inverted in patients with chronic graft‐vs.‐host disease (cGVHD), showed pseudonormalization during the course of MG. We succeeded in uneventful rapid tapering of prednisolone (PSL) using mycophenolate mofetil (MMF). Monitoring of OX40⁺CD4⁺ T cells supported the tapering of PSL and MMF as a marker of cGVHD activity. This case suggested the utility of MMF and monitoring of OX40⁺CD4⁺ T cells in the management of cGVHD‐associated autoimmune diseases.