Single-dose antithymocyte globulin in standard immunological risk kidney transplant recipients: efficacy and kinetics of peripheral blood CD3+ T lymphocyte modulation.

BACKGROUND

Polyclonal anti-T cell antibodies (ATG or thymoglobulin®) are used as induction therapy in kidney transplant recipients. This study evaluates the safety, efficacy, and CD3+ T lymphocyte modulation of two ATG regimens.

METHODS

The trial included two cohorts of kidney transplant recipients that were followed for one year. The study group, including standard immunological risk recipients, received one 3 mg/kg dose of ATG. The comparator group, including standard and high immunological risk kidney transplant recipients, received a fractionated dose regimen (up to four 1.5 mg/kg doses). Patient and graft outcomes and the kinetics of CD3+ T lymphocyte modulation in the peripheral blood were evaluated.

RESULTS

One hundred kidney transplant recipients were included in each group. The one-year incidence of treated acute rejection, and patient and graft survival did not differ between groups. Bacterial infections were significantly more frequent in fractionated-dose group patients (66% versus 5%; P = 0.0001). At one-year follow-up, there was no difference in the incidence of cytomegalovirus infection (P = 0.152) or malignancies (P = 0.312). CD3+ T lymphocyte immunomodulation in the single-dose group was more effective in the first two days after transplantation. After the third post-transplant day, CD3+ T lymphocyte modulation was more efficient in the fractionated dose group.

CONCLUSION

Both regimens resulted in low rejection rates and equivalent survival. The single and reduced dose regimen protects from the occurrence of bacterial infections. CD3+ T lymphocyte modulation occurred with different kinetics, although it did not result in distinct outcomes.