Evaluating Safety and Efficacy of Rabbit Antithymocyte Globulin Induction in Elderly Kidney Transplant Recipients

Abstract

Objectives: The optimal immunosuppression regimen for elderly kidney transplant recipients is poorly defined. We sought to evaluate the shortterm efficacy and safety of thymoglobulin in geriatric recipients of deceased-donor kidneys. Materials and Methods: A single-center, retrospective analysis was undertaken between elderly (≥ 65 years) (n=137) and nonelderly (n=276) kidney transplant recipients who received rabbit antithymocyte globulin induction and calcineurin inhibitor, mycophenolic acid, and prednisone maintenance. Results: The mean age was 70 versus 52 years. Fewer elderly patients had an earlier transplant or panel reactive antibodies > 20%, but had more machine perfused, older, and extended criteria donor kidneys. Elderly patients received lower rabbit antithymocyte globulin (5.4 vs 5.6 mg/kg; P = .04) and initial mycophenolic acid doses (1620 vs 1774 mg; P = .002), and experienced less delayed graft function (31.1% vs 50.0%; P < .001). Death-censored graft survival and graft function at 3 years and biopsy-proven acute rejection at 1 year were comparable; however, there was lower 3-year patient survival in elderly patients. Donor age was the only factor associated with reduced patient survival. Rates of malignancy, infection, or thrombocytopenia were similar; however, leukopenia occurred less frequently in elderly patients (11.7% vs 19.9%; P = .038). Conclusions: Elderly kidney transplant recipients receiving rabbit antithymocyte globulin did not experience different short-term graft survival, graft function or rates of infection, malignancy or hematologic adverse reactions than did nonelderly patients; they experienced fewer episodes of delayed graft function, but had lower 3-year patient survival.

New Directions for Rabbit Antithymocyte Globulin (Thymoglobulin®) in Solid Organ Transplants, Stem Cell Transplants and Autoimmunity

“…Limited retrospective data have suggested that early acute rejection may be more frequent if the total rATG dose is less than 6 mg/kg [ 66 ], although good outcomes with lower doses have also been reported [ 61 ]. Cumulative doses in the range of 3–6 mg/kg may be adequate in elderly recipients, in whom a retrospective analysis has reported excellent outcomes with an average total rATG dose of 5.4 mg/kg [ 67 ], and in lower-risk individuals such as living-donor recipients [ 68 ]. However, very low doses of rATG are likely to be inadequate, even in low-risk groups.…”

A Rationale for Age-Adapted Immunosuppression in Organ Transplantation

“…A retrospective study evaluating age-dependent risk profiles linked to rATG therapy in elderly renal transplant recipients (>65 years) found no differences for death-censored graft survival, graft function, rejection rates, infections, malignancies and hematologic adverse reactions when compared to non-elderly patients. 113 Of note, another retrospective analysis of >300 older renal transplant recipients (≥60 years) treated with reduced cumulative rATG doses showed comparable renal graft function but lower rates of rejection when compared to younger patients (<60 years). 114 …”

Comparison of clinical outcome of induction immunosuppressive therapy with thymoglobulin and standard therapy in kidney transplantation; a randomized double-blind clinical trial

“…The incidence of DGF depends on several factors such as obesity, high creatinine levels of donor, expanded criteria donor, race, donor age, and the cold ischemia time (28). DGF is associated with increased risk of acute allograft rejection and a risk factor for graft survival (28).…”