*Purpose: Steroid-avoidance in pediatric kidney transplants (txs) was found effective and safe with daclizumab induction. Upon daclizumab’s discontinuation, lymphocyte-depleting agents became used in this setting, with little safety and efficacy comparative data. To elucidate differences in early steroid-avoidance outcomes, we compared induction with antithymocyte globulin (ATG) to alemtuzumab in low risk deceased donor (DD) kidney txs.

*Methods: We retrospectively reviewed consecutive DD kidney txs performed January 2015 – September 2017 at two pediatric centers using different lymphocyte-depleting agents for steroid avoidance. We compared differences in immunosuppression (IS) and neutropenia management and abstracted clinical data including graft function, white blood cell (wbc) counts, PCR viremia results for CMV/EBV/BK, hospitalizations for infection, IS reduction/conversion, DSA development, biopsy proven acute rejection (BPAR), and graft and patient survival.

*Results: Per center-specific protocol, Center A txs (n=13; median age 13 yrs; 54% boys; 85% white) received ATG (1.5mg/kg/day IV daily x 4) with subsequent tacrolimus and MMF (600mg/m2/day). Center B (n=23; median age 11 yrs; 70% boys; 79% white) received alemtuzumab (0.3mg/kg, max 20 mg X1) with tacrolimus and higher dose MMF (1200mg/m2/d at tx, followed by taper to with a mean dose of ~900mg/m2/d at 1 year) . Valganciclovir and cotrimoxazole or atovoquone were used for 6-12 months for CMV/PCP prophylaxis. With neutropenia (ANC<1000), Group A reduced CMV/PCP prophylaxis and then MMF, whereas Group B started GCSF, with MMF reduction for ANC<500. Group B had lower wbc counts from 1-6 months, with similar wbc by 1 yr. 78% Group B needed GCSF at median 2.4 months for median ANC 715. GCSF was not provided in Group A (p<0.0001). Over yr 1, there were no fungal infections, and similar rates of bacterial infection hospitalizations. EBV and BK viremia were comparable (A38% vs B35%; A0% vs B4%), though Group A manifested more low-grade CMV viremia (46% vs 0%; p=0.0009), median onset 1.8 months, followed by early seroconversion. IS reduction did not differ between groups (A61% vs B39%; p=0.3), nor did time from tx to reduction (A2.5 vs B3.2 months; p=0.8). 30% Group B required MMF to azathioprine conversion for diarrhea, generally within first month. DSA at 1 year was similar (A8% vs B13%) with low rates of BPAR (A8% vs B9%). Need for steroid-based conversion was low ( A8% vs B4%; p>0.99). There were no graft losses and no differences in median eGFR at 30, 90, 180, and 365 days.

*Conclusions: Conclusion: Our findings suggest: 1)1 yr graft outcomes are excellent in steroid-avoidance regimens using either ATG or alemtuzumab induction; 2) Conversion rates to steroid-based therapy are low; 3) Alemtuzumab/high dose MMF is associated with lower wbc and more GCSF use, but infection rates are low; 4) Alemtuzumab/higher dose MMF results in more diarrhea and azathioprine conversion than ATG/lower dose MMF; 5) CMV viremia is seen more often with ATG use with infection prophylaxis reduction, however seroconversion occurs promptly.

« Back to 2019 American Transplant Congress