Basiliximab vs. No Induction Therapy in Kidney Transplant Recipients with a Low Immunological Risk Profile Receiving Tacrolimus/Mycophenolate/Steroids Maintenance Immunosuppression.

Background: Induction therapy with basiliximab is recommended in kidney transplant (KT) recipients with a low immunological risk (LIR) profile. Whether basiliximab is associated with a decreased risk of acute rejection (AR) and graft loss is controversial. Methods: In our institution, LIR patients (absence of anti-HLA antibodies before KT) are inducted with basiliximab in case of living-donor KT, while deceased-donor KT recipients receive no induction. Maintenance immunosuppression is similar, including a combination of tacrolimus (Tac), mycophenolate (MPA) and steroids. In this single-center retrospective study, we included all adult LIR patients who underwent KT between 1 January 2015 and 31 December 2022. Results: Of the 471 patients included, 354 received no induction and 117 received basiliximab. The median (IQR) number of HLA A-B-DR mismatches was 3 (2-3) and 2 (2-4) in the no induction group and the basiliximab group, respectively. The cumulative incidences in the no induction group vs. the basiliximab group of acute rejection and graft loss over 5 years post-KT were similar at 8.9% vs. 7.8% (p = 0.8) and 8.5% vs. 4.2% (p = 0.063), respectively. In multivariable Cox regression analysis, delayed graft function emerged as an independent risk factor for acute rejection (hazard ratio [HR] 2.75, 95% confidence interval [CI] 1.23-6.13, p = 0.014) and graft loss (HR 9.32, CI 4.10-21.1, p < 0.001). Conclusions: Basiliximab did not provide any advantage in terms of rate of acute rejection and graft survival within 5 years post KT compared with a strategy without induction therapy in patients with a low immunological risk profile receiving triple maintenance immunosuppression Tac/MPA/steroids.

Monoclonal Antibody Therapy in Kidney Transplant Recipients With Delta and Omicron Variants of SARS-CoV-2: A Single-Center Case Series.

Rationale & Objective: Neutralizing monoclonal antibody treatments have shown promising preliminary results in kidney transplant recipients infected with severe acute respiratory syndrome coronavirus 2. However, their efficacy in kidney transplant recipients infected with the Omicron variant has not been reported yet. Study Design: Single-center retrospective study. Setting & Participants: We included all consecutive kidney transplant recipients treated with monoclonal antibodies for severe acute respiratory syndrome coronavirus 2 infections (positive polymerase chain reaction on nasopharyngeal swab) between June 10, 2021, and January 14, 2022. Forty-seven kidney transplant recipients were included. All patients had symptoms evolving for ≤7 days and no oxygen therapy need at monoclonal antibody infusion. Results: Symptoms at diagnosis were mainly cough (n = 25; 53%) and fever (n = 15; 32%). Eighty-three percent of the cohort (n = 39) had been vaccinated with at least 2 doses before infection, of whom 30 (77%) had demonstrated a vaccine-induced humoral response. They were treated with either casirivimab-imdevimab (n = 16; 34%) or sotrovimab (n = 31; 66%) a median of 2 days (range, 0-6 days) after the onset of symptoms. Except for 1 mild allergic reaction during casirivimab-imdevimab infusion, no side effects were reported. The median viral loads at admission (day 0) and 7 days after monoclonal antibody infusion were 2,110,027 copies/mL (range, 1,000-153,798,962 copies/mL) and 1,000 copies/mL (range, 0-10,000,000 copies/mL), respectively. Genotypes were available for 22 kidney transplant recipients (47%). Omicron, Delta, and Gamma variants were identified in 13 (59%), 8 (36%), and 1 (5%) patients, respectively. In kidney transplant recipients infected with the Omicron variant, the median viral loads at day 0 and day 7 were 752,789 copies/mL (range, 4,000-12,859,300 copies/mL) and 1,353 copies/mL (range, 0-1,211,163 copies/mL), respectively. 2 kidney transplant recipients required hospitalization immediately after sotrovimab perfusion for oxygen therapy that was weaned in 3 days, allowing patients' discharge. None were admitted to the intensive care unit or died. Limitations: Small sample size, no control group. Conclusions: Neutralizing monoclonal antibody therapy is associated with positive outcomes in kidney transplant recipients with mild coronavirus disease 2019, including those infected with the Omicron variant.