Clinical utility of oral management in allogeneic hematopoietic stem cell transplantation recipients: microbiological evidence based on molecular analysis of oral bacteria

Purpose This study aimed to clarify the clinical utility of oral management to prevent bloodstream infections by oral bacteria microbiologically in patients undergoing allogeneic hematopoietic stem cell transplantation (ASCT). Methods Ten consecutive patients with hematological malignancies undergoing ASCT were enrolled in this study. We implemented dental treatments before transplantation, if required, and carried out oral hygiene instructions and oral management every other day after transplantation. Molecular analysis of bacterial DNA for seven oral species using a polymerase chain reaction (PCR) assay was performed for oral samples and peripheral blood once a week for 3 weeks after transplantation. Results Periodontitis was found in all 10 patients (mild grade in 3 and middle grade in 7) for whom basic periodontal therapy was conducted. Necessary dental procedures, including tooth extraction were performed in 5 patients. After transplantation, oral mucositis occurred in 10 patients (grade 1 in 3, grade 2 in 2, and grade 3 in 5) for whom oral hygiene instruction and oral care were continued every other day. PCR-identified three to six bacterial species in oral samples from nine patients, but none in peripheral blood from any patient during the observation period. Conclusions Our study suggests that oral management could prevent bloodstream infections by oral bacteria in ASCT recipients despite the existence of periodontitis or oral mucositis. Its utility was confirmed by microbiological evidence based on molecular data.