Extracorporeal photopheresis did not prevent the development of an autoimmune disease: myasthenia gravis

BACKGROUND Myasthenia gravis (MG) is a neuromuscular disorder characterized by an autoimmune defect in the neuromuscular junction. In most patients, the autoimmune attack is mediated by antibodies against the acetylcholine receptor (AChR) on the postsynaptic membrane. Deficient immunoregulation, including regulatory T cells, is consistently observed. Extracorporeal photopheresis (ECP) leads to the induction of regulatory T cells that mediate immunologic tolerance in autoimmune diseases; however, the data regarding MG are very limited. CASE REPORT Here, we report a patient who, during ongoing ECP therapy for his severe, refractory, chronic graft‐versus‐host disease (cGVHD), developed MG, although he responded very well to ECP, as indicated by the lowering of his chronic cGVHD severity grade to moderate. RESULTS Despite receiving ECP, our patient developed MG, which was resistant to treatment and required intensive care unit support. CONCLUSIONS Close surveillance is required when ECP is planned as one of the treatment alternatives in myasthenia gravis that develop in cGVHD.