BACKGROUND AND OBJECTIVES: Complicated vascular anomalies have limited therapeutic options and cause significant morbidity and mortality. This Phase II trial enrolled patients with complicated vascular anomalies to determine the efficacy and safety of treatment with sirolimus for 12 courses; each course was defined as 28 days. METHODS: Treatment consisted of a continuous dosing schedule of oral sirolimus starting at 0.8 mg/m² per dose twice daily, with pharmacokinetic-guided target serum trough levels of 10 to 15 ng/mL. The primary outcomes were responsiveness to sirolimus by the end of course 6 (evaluated according to functional impairment score, quality of life, and radiologic assessment) and the incidence of toxicities and/or infection-related deaths. RESULTS: Sixty-one patients were enrolled; 57 patients were evaluable for efficacy at the end of course 6, and 53 were evaluable at the end of course 12. No patient had a complete response at the end of course 6 or 12 as anticipated. At the end of course 6, a total of 47 patients had a partial response, 3 patients had stable disease, and 7 patients had progressive disease. Two patients were taken off of study medicine secondary to persistent adverse effects. Grade 3 and higher toxicities attributable to sirolimus included blood/bone marrow toxicity in 27% of patients, gastrointestinal toxicity in 3%, and metabolic/laboratory toxicity in 3%. No toxicity-related deaths occurred. CONCLUSIONS: Sirolimus was efficacious and well tolerated in these study patients with complicated vascular anomalies. Clinical activity was reported in the majority of the disorders.

Mixed donor chimerism is increasingly common in the pediatric hematopoietic stem cell transplantation (HSCT) setting because of the increased use of reduced-intensity preparative regimens for nonmalignant diseases. Donor lymphocyte infusion (DLI) is potentially useful in the treatment of mixed donor chimerism, but little are data available on the use of DLI in this setting. We conducted a retrospective review of 27 pediatric patients who received DLI for mixed donor chimerism between January 2006 and December 2010 after receiving a preparative regimen of alemtuzumab, fludarabine, and melphalan. Twenty-one patients (78%) were alive at a median of 35 months post-transplant. Seven patients (26%) sustained full donor chimerism after DLI only at a median of 35 months post-HSCT. Nine patients (33%) continued with mixed donor chimerism (median, 38% [range, 18% to 70%]) at a median of 37 months after DLI only. Five patients underwent unconditioned stem cell boosts or second conditioned transplants after no improvement in donor chimerism was seen following DLI. Donor source appeared to contribute to outcomes after DLI; patients with mismatched unrelated donors had earlier first decline in chimerism and timing of first DLI, a higher response rate to DLI, and an increased rate of graft-versus-host disease (GVHD). There was no response to DLI in patients with matched sibling donors. Ten patients, all with improvement in chimerism after DLI, developed acute GVHD after DLI, with 3 having grade III GVHD. Three patients developed chronic GVHD after DLI. These data illustrate the potential efficacy of DLI in the treatment of mixed donor chimerism after a reduced-intensity preparative regimen.

Objectives: The incidence of pediatric acute pancreatitis (AP) increased over the past 2 decades and is estimated to be 3 to 13 per 100,000. The impact of rising AP incidence on health care costs is unknown. Our aim was to examine pediatric AP admissions and associated hospital costs in the United States between years 2004 and 2014.Methods: Acute pancreatitis admission and cost data were extracted from the Pediatric Health Information System. We determined AP admission and cost percentages each year, as well as the ratio of AP cost to admission percentages to estimate AP “burden.” Length of stay, costs of hospitalization, and the effect of intensive care unit care on these estimates were examined.Results: Between 2004 and 2014, AP admission percentages increased (P= 0.002). Length of stay decreased over time (P< 0.0001) and was longer for those requiring intensive care unit care (P< 0.0001). Acute pancreatitis admissions cost per day significantly increased over time (P< 0.0001). Median AP cost percentage remained 1.2 to 1.7 times higher than AP admission percentage.Conclusions: Acute pancreatitis admissions constitute an expensive burden on the health care system relative to the percentage of all admissions. If AP admissions continue to increase, the cost of AP admissions may pose a substantial financial health care burden.