P-138: Continuous subcutaneous insulin infusion during hematopoietic stem cell transplantation in IPEX syndrome: a report of two cases

Introduction

Glycemic control in patients with diabetes during hematopoietic stem cell transplantation (HSCT) is challenging due to conditioning regimens, immunosuppression, infections, glucocorticoids, parenteral nutrition, and metabolic variability. Current guidelines recommend intravenous insulin in the acute phase. Evidence on continuous subcutaneous insulin infusion (CSII) during HSCT is limited, with no published case series in IPEX syndrome.

Objectives

To evaluate the feasibility and safety of CSII during HSCT in pediatric patients with IPEX syndrome and autoimmune diabetes.

Methods

Two pediatric cases with IPEX (FOXP3 pathogenic variant) underwent HSCT after myeloablative conditioning. Both were managed using a hybrid closed-loop (HCL) insulin delivery system: case 1 (1-year-8-month-old) in manual mode and case 2 (1-year-4-month-old) in automated mode. CSII was maintained throughout hospitalization with continuous glucose monitoring and treatment adjustments.

Results

Marked glycemic variability occurred during conditioning and early post-transplant phases. Case 1 showed mean glucose 217±85 mg/dL, CV 39%, TIR 35%, TDD 7.3 IU/day

(92% bolus). Case 2 showed mean glucose 164±49 mg/dL, CV 30%, TIR 65%, TDD 17.1 IU/day (54% bolus), with 39% autocorrections. Management included basal adjustments, temporary basal rates, automated correction boluses, active insulin time adjustments, target modifications, temporary targets, and carbohydrate overestimation with postprandial corrections. No diabetic ketoacidosis, device failure, or infusion-site infection occurred. CSII was maintained without interruption, avoiding intravenous insulin and intensive care unit admission.

Conclusions

CSII during HSCT in IPEX is feasible and safe, supporting its use as an alternative to intravenous insulin, with potential benefits including avoiding ICU admission, reduced invasiveness, and less monitoring. HCL, particularly in automated mode, may enhance glycemic management during HSCT.