*Purpose: Hypersensitized kidney transplant recipients (calculated panel reactive antibody (cPRA) ≥98%) may represent a population at high risk of posttransplant immunologic events. While access to transplantation for this group has increased with the new kidney allocation system, their optimal induction regimen remains uncertain. At our center we administer a single dose of rituximab in addition to ATG at induction in this high immunological risk cohort. The goal of this study was to compare the outcomes of patients receiving rituximab and ATG as induction, the majority of whom were hypersensitized, with highly sensitized patients (cPRA ≥80%) who received ATG alone.

*Methods: We abstracted clinical and laboratory data on adult patients with a pretransplant cPRA ≥80% who underwent kidney transplant at our institution between December 2014 and November 2018. All patients received a flow cross-match compatible graft. We excluded patients who underwent pretransplant desensitization or simultaneous multiorgan transplants. Baseline characteristics were abstracted by chart review. The exposure of interest was receipt of rituximab at induction. Examined 1-year posttransplant outcomes were 1) patient and death censored graft survival, 2) glomerular filtration rate (GFR), 3) de novo (dn) DSA formation, 4) biopsy proven T-cell or antibody mediated rejection, 5) the composite of dnDSA and rejection, and 6) BK viremia.

*Results: 57 patients received rituximab and ATG (Ritux) and 29 received ATG alone (Control). The Ritux group were (numerically) younger, more sensitized and received kidneys with a longer cold ischemia time and a lower kidney donor profile index. The majority of transplants were from deceased donors. ATG dose was similar and maintenance immunosuppression consisted of tacrolimus, mycophenolate mofetil, and prednisone for both groups. 1-year patient and death censored graft survival was similar for Ritux and Control (98% vs 100% and 96% vs 96%, respectively). 2 patients with primary graft non-function (1 in each group) and 1 patient who died early posttransplant (in Ritux) were excluded from the remaining outcome analyses which are summarized in Table 1.

*Conclusions: The addition of rituximab to ATG as induction for hypersensitized patients appears to be safe and is associated with excellent 1-year outcomes. We observed a numerically lower number of immunologic events during the first year post transplant in patients who received rituximab. Our observations warrant further evaluation of anti-B cell therapy induction for hypersensitized patients undergoing kidney transplant.

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