Mixed Acute Rejection: Comparison of Therapeutic Results with Anti-T Cell Antibody- and Proteasome Inhibitor-Based Regimens
University of Cincinnati
The Christ Hospital
Meeting: 2013 American Transplant Congress
Abstract number: D1593
Background: Mixed acute rejection (MAR) has been defined as acute rejection consisting of both cellular and humoral components. No data exist regarding MAR treatment outcomes, nor whether T cell- or B cell-targeted therapies provide optimal results. The aim of this study is to evaluate the outcomes of different treatments of MAR in kidney transplant recipients.
Methods: MAR was defined as coexisting acute cellular- and antibody-mediated rejection. Patient groups examined included two from a prospective randomized MAR trial (Groups B and C), which were compared to an off-protocol standard of care regimen (Group A). Group A: bortezomib (BTZ) + rituximab (Ritux); Group B: BTZ + rabbit anti-thymocyte globulin (rATG); Group C: rATG + Ritux.
Results: 27 patients were included in the study. As shown in the table, all three groups had similar results in renal function, donor-specific antibodies (DSA), Banff scores. Five patients (18.5%) experienced graft loss: there was no difference among the three groups.
| A: BTZ+Ritux (n=7) | B: BTZ+rATG (n=10) | p-value (A vs B) | C: rATG+Ritux (n=10) | p-value (A vs C) | |
| Age(yr)† | 49.5 ± 14.5 | 41.5 ± 13.3 | NS | 36.5 ± 5.5 | 0.019 |
| Deceased donor transplant, n (%) | 3 (42.8%) | 5 (50%) | NS | 3 (30%) | NS |
| Female, n (%) | 3 (42.8%) | 4 (40.0%) | NS | 3 (30%) | NS |
| Late (>6 mos) MAR, n (%) | 5 (71.4%) | 9 (90.0%) | NS | 7 (70%) | NS |
| AA race, n (%) | 2 (28.6%) | 5 (50%) | NS | 2 (20%) | NS |
| Time to rejection (mos)† | 30.7 ± 26.6 | 35.4 ± 27.1 | NS | 31.5 ± 47.3 | NS |
| Post-tx follow-up (mos) | 15.8 ± 13.5 | 18.6 ± 11.7 | NS | 14.1 ± 13.0 | NS |
| eGFR at baseline (ml/min/1.73m²)† | 80 ± 13.5 | 62.3 ± 9.9 | 0.007 | 71.1 ± 23.9 | NS |
| eGFR at rejection diagnosis (ml/min/1.73m²)† | 26.8 ± 15.5 | 32.9 ± 17.0 | NS | 37.4 ± 28.3 | NS |
| eGFR maximum post-tx (ml/min/1.73m²)† | 44.9 ± 17.7 | 46.0 ± 17.1 | NS | 44.6 ± 20.3 | NS |
| % decrease in eGFR post-tx | 55.3 ± 10.44 | 29.2 ± 16.7 | NS | 32.7 ± 40.4 | NS |
| Pre-tx iDSA level (MFI)† | 11,750 ± 8202 | 8252 ± 4109 | NS | 9358 ± 6667 | NS |
| Nadir iDSA level (MFI)† | 4363 ± 5760 | 3175 ± 2275 | NS | 6392 ± 5778 | NS |
| % reduction in nadir iDSA level (MFI)† | 52.8 ± 30.4 | 64.7 ± 21.7 | NS | 50.0 ± 29.4 | NS |
| Change in Banff scoring post-tx† | |||||
| g + ptc | -0.6 ± 0.8 | -0.4 ± 0.4 | NS | 0.1 ± 0.9 | NS |
| i + t | -1.4 ± 1.9 | -1.2 ± 1.3 | NS | -1.3 ± 1.8 | NS |
| c4d | -0.3 ± 0.7 | 1.0 ± 0 | NS | 0 ± 0.8 | NS |
| cg | 0.1 ± 0.4 | -0.2 ± 0.4 | NS | 0 | NS |
| ci + ct + cv | 0.6 ± 1.3 | 0.6 ± 3.1 | NS | 0.9 ± 2 | NS |
| Graft loss, n (%) |