Safety and Accuracy of Professional Continuous Glucose Monitoring in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Hyperglycemia in the early days following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a well-known risk factor for acute graft-versus-host disease (GVHD) and non-relapse mortality. The FreeStyle Libre Pro, a factory calibrated continuous glucose monitoring (CGM) device, has been used for the retrospective analysis of glucose testing in patients with diabetes. We assessed the safety and accuracy of the device in patients undergoing allo-HSCT. We recruited eight patients who underwent allo-HSCT between August 2017 and March 2020. They wore the FreeStyle Libre Pro on the day before or on the day of transplantation until 28 days after transplantation. Adverse events, especially bleeding and infection, were monitored to assess safety, and blood glucose levels were measured and compared with the device values. None of the eight participants experienced bleeding that was difficult to stop from the sensor site or local infection that required antimicrobial administration. The device value was well correlated with blood glucose (correlation coefficient r=0.795, P<0.01); however, the overall mean absolute relative difference was 32.1%±16.0%. Our study demonstrated the safety of FreeStyle Libre Pro in allo-HSCT patients. However, the sensor results tended to be lower than the blood glucose levels.