Patients and protocol design
This randomized phase II study was performed to investigate the effects of a mouthwash containing HST for prevention of OM in patients undergoing HSCT in Nagasaki University Hospital. The study protocol was approved by the Clinical Research Review Board of Nagasaki University on 28 April 2020 (#CRB7180001). Thirty patients scheduled to receive allogeneic grafts were enrolled from July 2020 to December 2021. After providing written informed consent, the patients underwent oral examinations and continuously received professional oral care interventions during data collection. They were randomly assigned to 2 groups of 15 patients each. Patients using HST were instructed to wash their mouth three times a day with 2.5 g HST (TJ-14; Tsumura, Tokyo, Japan) dissolved in 40 mL saline solution after brushing after meals. Patients assigned to the control group were instructed to wash their mouth using only saline solution. The duration of HST use was from initiation of the conditioning regimen of HSCT to the date of engraftment. Concomitant drugs were not restricted. If engraftment failure occurred more than 28 days after transplantation, data collection was finished.