Abstracts

INFECTIOUS COMPLICATIONS WITH RABBIT ANTI-THYMOCYTE GLOBULIN (rATG) INDUCTION THERAPY IN PEDIATRIC STEROID FREE LIVER TRANSPLANTATION.

Kyle Soltys, Rakesh Sindhi, Amy Smith, Michael Green, George Mazariegos. Division of Transplant Surgery, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA; Division of Infectious Diseases, Children’s Hospital of Pittsburgh.

Background: The concept of tolerogenic immunosuppression has led to our use of rATG induction therapy with post-operative use of tacrolimus monotherapy. Our experience with this regimen has been submitted separately however, a detailed examination of post-operative infectious complications is warranted.

Methods: Between 8/2001-8/2004 67 children (age 5 months–17 years) received 70 primary liver allografts. Pre-treatment and induction therapy was with 4–5 mg/kg rATG. Oral tacrolimus (TAC) was started within 24–48 hours post-transplant with a target trough of 10–15 ng/ml. Cases performed on patients receiving second allografts, combined liver-kidney transplants, chemotherapy or those performed before the standardization of EBV monitoring were excluded. Thus, the study group is comprised of 49 children transplanted between March, 2002 and September, 2004. These included 7 living-donor segmental, 5 cadaveric segmental and 37 whole cadaveric liver transplants.

Results: Overall patient and graft survival is 100% at a mean follow-up of 15.2 ±9.1 months (range 2.3–33.2 months). Within 6 months, 23/49 (47%) experienced acute cellular rejection and 4 received OKT3 for steroid-resistant ACR at a mean of 52.5 (range 5–122) days post Tx. Two patients had CMV disease, manifested by hepatitis on post-op days 80 & 34. Both were high-risk for CMV infection based on pre-Tx serologies, had an episode of ACR prior to CMV disease and received standard prophylaxis with intravenous ganciclovir. EBV related complications included two cases of PTLD. The first case was a patient who was non-compliant with EBV PCR follow-up and developed a non-EBV spindle cell PTLD of the liver on POD 440. The other patient developed PTLD diagnosed during ultrasound guided biopsy on POD 100. One case of EBV hepatitis was also discovered on POD 53. All of these were high-risk for EBV and all had prior augmented immunosuppression for ACR. The incidence of other viral infections as well as episodes of CMV and EBV viremias were also examined. There was no increase in bacterial or fungal infections in this series of patients.

Conclusion: The incidence of post-operative viral, bacterial and fungal infections associated with rATG is similar to our pre rATG induction experience. The incidence of PTLD (4%) is also similar to other series of pediatric liver Tx.