Study Design: SCID infants receiving an unconditioned haploidentical transplant will be
started on Sirolimus (0.05 mg/kg/day) day -5 for Acute Graft-Versus-Host Disease (aGVHD)
prophylaxis. Sirolimus levels will be monitored with goal sirolimus trough level of 5-8
ng/mL. Patients will be monitored for signs of aGVHD as defined by UCSF SOP CL 221.06 through
day +100. Sirolimus will be tapered once T-regulatory cell to CD4 effector cell ratio is > or
= 9%.
Setting: Inpatient BMT Unit Benioff Children's Hospital at UCSF Medical Center
Study Subjects: 15 infants with diagnosis of maternally engrafted T cells SCID by CA Newborn
screen receiving unconditioned haploidentical HSCT
Main Outcome Measures: Incidence of aGVHD (dermatitis, hepatitis, enteritis) as defined by
SOP CL 221.06 by Day +100.
Hypothesis 1. Patients placed on sirolimus prophylaxis will have lower incidence of aGVHD
compared to historical controls.
Hypothesis 2. Lower doses of sirolimus milligram per kilogram will be required to maintain
goal troughs of 5-8 ng/mL.