Analysis of CD8+CD28- T-suppressor cells in living donor liver transplant recipients.

Background: Human CD8+CD28- T-suppressor (Ts) cells have been considered to indicate a reduced need for immunosuppression in pediatric liver-intestine transplant recipients and recipients of deceased heart-kidney transplants. However, in adult-to-adult living donor liver transplantation (A-A LDLT) little information is available and the clinical significance is still unknown.
Methods: Flow cytometry was used to detect the population of CD8+CD28- Ts cells present in peripheral blood in A-A LDLT recipients (n=31), patients with end-stage liver disease (n=24) and healthy controls (n=19). Meanwhile, we tested the graft function and trough levels of immunosuppression in recipients. The clinical and follow-up data of 31 transplant recipients were analyzed.
Results: Compared with diseased controls (P=0.007) and healthy individuals (P=0.000), a notable expansion of CD8+CD28- Ts cells was found in recipients of A-A LDLT. This was associated with graft function, levels of immunosuppression and rejection episodes.
Conclusions: To monitor the CD8+CD28- Ts cells levels is important to evaluate the immune state of recipients. Meanwhile, it is also important to promote expansion of CD8+CD28- Ts cells in recipients of A-A LDLT, not only to sustain good graft function and decrease the dosage of immunosuppressants, but also to reduce the occurrence of rejection.