PS1551 INTENSIVE ORAL CARE CAN REDUCE BLOOD STREAM INFECTION POST NEUTROPHIL ENGRAFTMENT IN ALLOGENEIC HSCT

Background: Bloodstream infection (BSI) is a major complication of allogeneic hematopoietic stem cell transplantation (HSCT) and one of the major causes of early mortality. BSI can occur before and after neutrophil engraftment (abbreviated as pre‐BSI and post‐BSI, respectively). Although pre‐BSI has been well studied, the risk factors for post‐BSI and preventative measures remain unknown. As oral care during HSCT can prevent severe mucositis and improve the QOL for HSCT recipients, it may also prevent BSI after HSCT. Aims: We evaluated the characteristics of pre‐/post‐BSI and clarified whether oral care can prevent BSI. Methods: We analyzed 176 consecutive adult patients, including 122 with acute leukemia, 21 with myelodysplastic syndrome, 13 with malignant lymphoma, 6 with aplastic anemia and 14 with other hematological malignancies, who received HSCT and underwent neutrophil engraftment between 2006 and 2017 at our institute. The median age at HSCT was 42 (16–67). The donor type was matched‐related for 46 patients (26%), matched‐unrelated for 31 (17%) and other for 99 (56%). The graft source was bone marrow for 69 patients (39%), peripheral blood stem cells for 57 (32%) and cord blood for 50 (28%). Fifty‐five (31%) patients had a high (3≥) HCT‐CI score. HSCT was performed in 64 (36%) patients who were at high‐risk disease status defined as non‐remission acute leukemia/lymphoma or myelodysplastic syndromes with excess blasts. Fluoroquinolone (FQ) for prophylaxis was administered to 89 (50%) patients. We classified oral care as follows: intensive care by dental specialist for 92 (I‐care) and self‐oral care for 84 patients (S‐care). In both groups, the oral cavity was assessed by a dental specialist, dental treatment was performed and the patients were instructed on appropriate oral self‐care before HSCT. In addition, a dental specialist visited the I‐care group at least twice a week, evaluated oral mucositis and cleaned the oral cavity during the early phase of HSCT. Central venous catheters were required for all patients before conditioning chemotherapy. Results: A total of 83 BSI events occurred in 70 (40%) patients until day 180 from HSCT. The incidences of pre‐ and post‐BSI were similar (21.6% vs. 22.2%, p = 1.0). Furthermore, there was no difference in the ratio of gram‐positive and gram‐negative bacteria as the BSI pathogens between pre‐ and post‐BSI (73.8%/26.2% vs. 83.0%/14.9%, p = 0.29). FQ prophylaxis did not affect pre‐ or post‐BSI. The incidence of pre‐BSI was the same between the I‐ and S‐care groups (21.4% vs 21.7%, p = 1). However, that of post‐BSI was significantly lower in the I‐care group (12.0% vs 29.8%, p  < 0.001) than in the S‐care group. In the multivariate analysis adjusted for age, HCT‐CI, disease status, donor type, graft source, conditioning regimen and FQ prophylaxis, I‐care was found to be an independent factor for reducing the incidence of post‐BSI (OR = 0.32 (0.11–0.93), p = 0.03). Summary/Conclusion: Regardless of FQ prophylaxis, intensive oral care by dental specialists during the early phase of HSCT can reduce the incidence of post‐BSI and may improve the QOL for patients.