CD19 and neuromyelitis optica: In a case series of 5 AQP4-NMO patients resistant to previous immunotherapy (in 2 cases rituximab), bortezomib resulted in relapse control during the 1 year of follow-up in 4 of 5 treated patients, along with reduction of AQP4 titer, CD19 B cells, and CD138 plasma cells [140].