Tacrolimus is effective for neuromyelitis optica spectrum disorders with or without anti-AQP4 antibody.

•Prevention of recurrence is crucial for neuromyelitis optica rerated disorders (NMOSD).•The combined use of TAC and PSL clearly reduced the Annualized relapse rate of NMOSD with or without anti-AQP4 antibody.•In the anti-AQP4 antibody-positive NMOSD, both PSL dose and EDSS score decreased compared to the initial TAC use.