1. Successful sequential cord blood stem cell transplant and intestinal-colon transplant for combined immunodeficiency and intestinal failure. kyle.soltys@chp.edu OBJECTIVES MATERIALS AND METHODS CONCLUSIONS Our patient had lymphopenia and hypogammaglobulinemia without response to pneumococcal antigens, PHA and tetanus, with a normal proliferative response to candida and ConA. and required chronic IVIG treatment. At the time of evaluation, she was found to have worsening lymphopenia and low T-cell receptor excision circle (TREC) levels. Due to the worsening immune function and need for intestinal transplant, she underwent a cord blood stem cell transplant (BMT) after induction with hydroxyurea, altezumab, fludarabine, melphalan and thiotep. She was maintained on tacrolimus and except for mild cutaneous GVHD one month after transplant, did well. Two months post-BMT, she had mixed chimerism: whole-blood (68% donor) and T-cell (100% donor) and was also found to have switched blood-typing from AB to O. Five months after BMT, she received a four antigen HLA matched intestine/colon allograft from a deceased donor. She received balsiliximab and was maintained on tacrolimus and steroids. Donor pretreatment was not employed. Weekly surveillance endoscopy revealed acute cellular rejection (ACR) three weeks after transplant. This resolved with steroid therapy and mycophenolate mofetil was added to her immunosuppressive regimen. Once the ACR resolved, she was discharged without parenteral nutrition. She was readmitted with severe CMV viremia, pneumonia and enteritis a month later, requiring intubation and causing massive intestinal hemorrhage, associated with a small enterocutaneous fistula to the midline incision. Treatment with cytogam and ganciclovir, bowel rest and supportive measures, along with immunosuppression reduction, resulted in a full recovery and resolution of the enterocutaneous fistula. She was discharged after two months and remains off parenteral nutrition and on a regular diet. Her peripheral chimerism reveals 100% BM donor and <5% intestinal donor. Six months after transplant, she was found to have a 1.5cm lesion in her right lung and underwent a thoracoscopic resection. Pathology revealed a plasmacytoid PTLD with negative margins. Repeat imaging was negative 2 months after the resection and she has tolerated immunosuppressive reduction (tacrolimus troughs of 5ng/ml) without recurrence of rejection. Conclusion. Sequential and closely matched bone marrow and intestinal transplants can be performed safely, though significant early immunologic and infectious morbidity was experienced in our patient. Close HLA matching and avoidance of pre-conditioning seems warranted. Donor treatment with lympho-ablation was not employed and without resultant donor derived graft versus host disease (GVHD). E-Poster 216 Herein we describe our experience treating a 16 year old girl suffering from SCID and intestinal failure from atresia with a sequential cord blood stem cell transplant, followed by a four antigen HLA matched intestine/colon allograft