Impact of Rabbit Antithymocyte Globulin Dose on Long-term Outcomes in Heart Transplant Patients

Abstract

These retrospective data suggest that a cumulative rATG dose of 4.5 to 7.5 mg/kg may offer a better risk-benefit ratio than lower or higher doses, with acceptable rates of infection and posttransplant malignancy. Prospective trials are needed.

A Proposal for Early Dosing Regimens in Heart Transplant Patients Receiving Thymoglobulin and Calcineurin Inhibition

“…Regarding malignancy, the rarity of events makes an accurate assessment of the impact of specific rATG doses difficult. In the retrospective study by Aliabadi et al, 40 in which patients were followed up for a median of 104 months, Kaplan-Meier estimates for freedom from malignancy did not differ between the 3 rATG dose groups (<4.5 mg/kg, 4.5-7.5 mg/kg, or >7.5 mg/kg) but the time to tumor development was significantly shorter in the high-dose cohort. A recent systematic review concluded that the risk of posttransplant lymphoproliferative disease (PTLD) is not influenced by rATG dose across all organ types or specifically in heart transplantation.…”

“…A retrospective single-center analysis of 523 heart transplant patients by Aliabadi et al 40 analyzed infection rates in the subgroup of patients given a total rATG dose of less than 4.5 mg/kg, 4.5 to 7.5 mg/kg, or greater than 7.5 mg/kg. Kaplan-Meier estimates indicated the 10-year incidence of severe infection to be 37%, 23%, and 45%, respectively ( P < 0.001).…”

“…On multivariate analysis, the cohort given 4.5 to 7.5 mg/kg had a reduced risk of severe infection compared with the highest-dose group (hazard ratio [HR], 1.71; P = 0.015) as might be expected, but also compared with the lowest-dose group (HR, 1.86; P = 0.011). 40 This may have been due to the fact that higher rates of rejection under low-dose rATG necessitated intensive antirejection therapy, or that in patients who developed infection rATG therapy was discontinued. Cytomegalovirus infection was estimated to occur in 20%, 23%, and 35% by year 2 ( P = 0.009), with CMV disease in 5%, 6%, and 23% ( P = 0.015).…”

“…The retrospective analysis by Aliabadi et al 40 is helpful regarding the association between rATG dose and immunosuppressive efficacy in patients given delayed CNI. The mean time to start of CsA or tacrolimus was 4.3 days and 4.9 days, respectively.…”

A Review of Induction with Rabbit Antithymocyte Globulin in Pediatric Heart Transplant Recipients

“…There is tentative evidence, however, concerning the question of whether lower rATG dosing reduces the risk for PTLD. Aliabadi et al performed a retrospective single-center analysis in which outcomes in 523 HTx patients (including 19 patients aged 5–18 years) were assessed according to cumulative rATG dose (<4.5 mg/kg, 4.5–7.5 mg/kg, or >7.5 mg/kg) [ 63 ]. There were no cases of PTLD in patients given a total dose of up to 7.5 mg/kg.…”