437 Absence of rejection after human liver orthotopic liver transplantation (OLT) is associated with leukocyte apoptosis, increased lymphocyte activation and higher donor cell chimerism

HEPATOLOGY, Vol. 38, No. 4, Suppl. 1, 2003

AASLD ABSTRACTS

going fiver transplant induded the following: hepatitis B/C, 1,299; alcoholic, 492; PBC/PSC, 277; hepatocellular cancer, 651; other, 26. The distribution of lab MELD scores at transplant include the following: MELD < 10, 297; 10-19, 1357; 20-29, 699; 30+, 392. Cox regression analysis revealed that the MELD score P<0.001, donor age P<0.002, and previous fiver transplant P<0.003 were all significant risk factors for graft loss. Relative risks of graft failure within three months increased above a MELD of 25 [ref] as follows: MELD 25, RR 1; MELD 30, RR 1.2; MELD 35, RR 1.6; MELD 40, RR 2.1. There were no differences in graft survival based on race, gender, or etiology of fiver disease. CONCLUSION: Increasing MELD score above 25 is associated with an increased risk of graft loss. In addition to MELD score, increasing donor age and having a previous transplant are significant factors in predicting diminished graft survival. Disclosures: Erick Edwards - No relationships to disclose Richard Freeman - No relationships to disclose A n n Harper - No relationships to disclose Russell H Wiesner - No relationships to disclose

436

TERM FOLLOW-UP OF DE-NOVO AUTOIMMUNE HEPATITIS IN PEDIATRIC LIVER TRANSPLANT RECIPIENTS. Shikha S Sundaram, Brian Stahulak, Joan M Lokar, Peter L O N G

F Whitington, ~ stella M Alonso, Northwestern University, Chicago, IL Background: Graft dysfi~nction secondary to de novo autoimmune hepatitis after liver transplantation in patients without previous autoimmune diseases has been well described. This entity must be carefizlly distinguished from other causes of graft dysfimction such as allograft rejection and infection. As patients carrying this diagnosis become older, the long-term impact of this disease can be assessed. Aim: To evaluate the long term follow-up of de novo autoimmune hepatitis (AIM) in pediatric fiver transplant patients. Methods: We retrospectively reviewed the medical records of liver transplant recipients followed at our institution, diagnosed with de novo autoimmune hepatitis. Criteria for diagnosis induded a clinical pattern of chronic hepatitis and positive auto-antibodies or dassic histology. Demographic, laboratory, treatment and outcome data were collected for each patient. Results: De novo AIH was diagnosed in 9.3% (171182) of transplant recipients. Of these patients, none had a previous autoimmune diagnosis, 64.7% were female and 58.8% carried the primary diagnosis of biliary atresia. De novo AIM was diagnosed a mean of 6.47 years (range 2.04-15.42) after transplantation. Seventy one percent of patients were positive for autoantibodies: 52.9 % were positive for anti-nudear antibody, 23.5% for anti-smooth musde antibody and 0% for anti-liver kidney microsomal antibody. The average ALT elevation was 224 (range 61-486) and AST elevation 166 (range 52-346). An elevated GGTP was seen in 70.6% of patients. All patients were Hepatitis C PCR negative. At the time of diagnosis, 12 patients were being treated with cydospofine, 5 with FKS06, and 7 with steroids in addition to caldneurin inhibitors. After diagnosis, all patients received standard therapy with 1-2mg/kg of steroids. In addition, 89% (15117) began Azathioprine and 24% had their calcineurin inhibitor dose decreased. After a mean of 2.6 years of follow-up (range 0.53-5.93), 59% remain steroid dependent and 12% are off steroids. One patient was re-transplanted for biliary complications and 1 patient required conversion to Sirolimus. Conclusion: Diagnosis of de novo AIM requires a high index of suspicion as auto-antibodies are often negative. Steroid therapy, often with the addition of azathioprine, is effective in controlling disease. Many patients, however, become steroid dependent in order to remain in remission. Disclosures: Estella M Alonso - No relationships to disclose Joan M Lokar - No relationships to disclose Brian Stahulak - No relationships to disclose Shikha S S u n d a r a m - No relationships to disclose Peter F Whifington - No relationships to disclose

371A

437 ABSENCE OF REJECTION AFTER HUMAN LIVER ORTHOTOPIC LIVER TRANSPLANTATION (OLT) IS ASSOCIATED WITH LEUKOCYTE APOPTOSIS, INCREASED LYMPHOCYTE ACTIVATION AND HIGHER DONOR CELL CHIMERISM. Andrew Clouston, Daina M Vanags, Wenyi Gu, ~ lizabeth

Powell, Julie R Jonsson, University of Queensland, Brisbane, Australia Background. Liver allografts have an improved outcome compared with other solid organ grafts, and rodent studies have suggested that activation-associated lymphocyte death may play a key role. Studies from our laboratory have s h o w n increased levels of apoptotic lymphocytes in h u m a n liver grafts compared with renal grafts and native liver. Although the levels of apoptosis did not differ significantly between those who developed acute rejection (REJ) and those who did not (NR), the earliest timepoint studied was 3 days post-OLT. We hypothesized that the very early postoperative period (within 48 hours) would reveal a relationship between leukocyte apoptosis and rejection. Aims. The aim of this study was to determine the amount of early leukocyte apoptosis and its relationship with the degree of lymphocyte activation, s u b s e q u e n t rejection status and degree of donor cell chimerism. Methods. Peripheral blood mononuclear cells were isolated from 76 patients undergoing OLT and were collected on the day prior, 5 hrs after reperfusion (Day 0) and 24 hrs post-OLT (Day 1). DNA and RNA were p r e p a r e d and real-time PCR used to quantify apoptosis (ligation-mediated PCR), lymphocyte activation (IL-2, IFN-gamma, IL-10, CD40 ligand, using GAPDH as an internal standard) and donor cell chimerism (Y chromosome DYZ3 or donor-specific DRB1). Results. The m e a n level of circulating apoptotic cells in Day 1 recipient PBMC was higher t h a n healthy controls (0.9% -+ 0.2 vs 0.2% -+ 0.1, p-0.013). Apoptosis was greater in NR (1.1% -+ 0.3) compared with REJ (0.3% -+ 0.1, p-0.021). On Day I the PBMC from NR h a d increased expression of IFN-gamma (p -0.006), IL-10 (p-0.016), CD40 ligand (p-0.02) and IL-2 (trend) compared with REJ, despite no difference in lymphocyte counts. Donor cell chimerism on Day I did not differ between the groups indicating that this was unlikely to account for increased leukocyte apoptosis in the NR group. Interestingly, the level of chimerism 5 hrs postreperfusion (Day 0) was significantly higher in NR (3.8% -+ 0.6) compared with REJ (1.2% -+ 0.4, p-0.004) and there was a close correlation between chimerism on Day 0 and PBMC cytokine expression on Day 1 (r-0.58, p-0.006). Conclusions. Patients who did not experience rejection h a d a paradoxical increase in markers of lymphocyte activation at Day 1, in association with higher levels of leukocyte apoptosis. This suggests that recipient cell death may have a role in graft acceptance and reduced acute rejection in h u m a n OLT. The higher donor cell chimerism seen in Non-Rejectors implicates the passenger leukocytes in the process of heightened cell death. Disclosures: Andrew Clouston - No relationships to disclose Wenyi Gu - No relationships to disclose Julie R Jonsson - No relationships to disclose Elizabeth E Powell - No relationships to disclose Daina M Vanags - No relationships to disclose