Original Article DOI 10.3349/ymj.2009.50.6.784 pISSN: 0513-5796, eISSN: 1976-2437 Yonsei Med J 50(6): 784-788, 2009 Withdrawal of Immunosuppression in Pediatric Liver Transplant Recipients in Korea Jee Hyun Lee,1 Suk-Koo Lee,2 Hae Jeong Lee,3 Jeong Meen Seo,2 Jae Won Joh,2 Sung Joo Kim,2 Choon Hyuck Kwon,2 and Yon Ho Choe3 1Department of Pediatrics, Kangnam Sacred Heart Hospital, Hallym University School of Medicine, Seoul; Departments of 2Surgery and 3Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Purpose: We identified pediatric liver transplant recipients with successful withdrawal of immunosuppression who developed tolerance in Korea. Materials and Methods: Among 105 pediatric patients who received liver transplantation and were treated with tacrolimus-based immunosuppressive regimens, we selected five (4.8%) patients who had very low tacrolimus trough levels. Four of them were noncompliant with their medication and one was weaned off of immunosuppression due to life threatening posttransplant lymphoproliferative disorder. We reviewed the medical records with regard to the relationship of the donor-recipients, patient characteristics and prognosis, including liver histology, and compared our data with previous reports. Results: Four patients received the liver transplantation from a parent donor and one patient from a cadaver donor. A trial of withdrawal of the immunosuppressant was started a median of 45 months after transplantation (range, 14 months to 60 months), and the period of follow up after weaning from the immunosuppressant was a median of 32 months (range, 14 months to 82 months). None of the five patients had rejection episodes after withdrawal of the immunosuppression; they maintained normal graft function for longer than 3 years (median, 38 months; range, 4 to 53 months). The histological findings of two grafts 64 and 32 months after weaning-off of the medication showed no evidence of chronic rejection. Conclusion: The favorable markers for successful withdrawal of immunosuppression were 1) long-term (> 3 years) stable graft function, 2) no rejection for longer than 1 year after withdrawal of immu- nosuppression, 3) non-immune mediated liver diseases, and 4) pediatric patients. Key Words : Pediatric liver transplantation, withdrawal of immunosuppression, tacrolimus Received: October 24, 2008 Revised: January 12, 2009 Accepted: January 12, 2009 Corresponding author: Dr. Yon Ho Choe, Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea. Tel: 82-2-3410-3539, Fax: 82-2-3410-0043 E-mail: i101016@skku.edu ∙The authors have no financial conflicts of interest. © Copyright: Yonsei University College of Medicine 2009 INTRODUCTION As survival has improved after liver transplantation, with potent immunosup- pressants like tacrolimus, the quality of life and long-term immunosuppression have become important factors in addition to acute rejection and graft survival. There are reports on liver transplant recipients who acquire tolerance.1 We identified pediatric liver transplant recipients with successful withdrawal of immunosuppression who developed tolerance and analyzed the patient charac- teristics, donor-recipient relationship, immunosuppressant regimens, and prognosis. MATERIALS AND METHODS From April 1997 to July 2007, 105 pediatric liver transplantation recipients received tacrolimus-based immunosuppression at Samsung Medical Center, 784 Yonsei Med J http://www.eymj.org Volume 50 Number 6 December 2009