Successful kidney transplantation in highly sensitized patients

Rabbit antithymocyte globulin induces human lymphocyte activation, proliferation, and apoptosis in the absence of complement: an experimental study

Rabbit antithymocyte globulin (rATG) has become the first choice for induction therapy in HLA-presensitized patients undergoing organ transplantation. Meanwhile, complement inhibitors have been approved for preventing or treating antibody-mediated rejection in these patients. The biological effects of rATG on lymphocytes in cases of complement deficiency or significant inhibition are not yet clear. We measured lymphocyte activation, proliferation, and apoptosis in response to rATG treatment in the absence of complement. T-cell subsets were analyzed transcriptomically features to rATG stimulation. Activation-related phenotypes on T cells were determined in patients after rATG administration. We found that rATG treatment led to lymphocyte activation and proliferation in vitro without the addition of complement. A dose-dependent apoptosis in rATG-treated lymphocytes was detected, which was partially caspase-3-dependent but Fas/FasL-independent. T cells were more sensitive to rATG stimulation than were non-T cells. Both CD4⁺ T cells and CD8⁺ T cells upregulated a series of genes related to cell activation, cytokine production and apoptosis to rATG stimulation. CD69 and CD25 levels in surviving T cells were increased in patients after rATG administration. These findings indicate that rATG can stimulate lymphocyte activation, proliferation, and apoptosis in the absence of complement. Biologic effects of rATG other than complement-dependent cytotoxicity need to be concerned.

Immune-Related Adverse Drug Reactions and Immunologically Mediated Drug Hypersensitivity

Biologic and other therapies used for the treatment of immune-mediated hypersensitivity conditions, and in people with immune-mediated hypersensitivity, can trigger a wide variety of immune-related adverse drug reactions and immunologically mediated drug hypersensitivities. These range from acute-onset immunoglobulin E-mediated allergies to delayed-onset T-cell-mediated hypersensitivities. Certain therapeutic and diagnostic agents can directly activate mast cells. Biologic agents used to treat immune-mediated hypersensitivity can also globally upregulate or downregulate the immune system leading to pathologic reactions, including cytokine storm and hypogammaglobulinemia.

Therapeutic Effect of Plasmapheresis and Intravenous Immunoglobulin in Recipients of Kidney Transplant With High Panel-reactive Antibody Levels: A Single-center Experience

OBJECTIVE

High panel-reactive antibody (PRA) levels limit patients' access to kidney transplantation from potential living donor candidates and decrease renal graft survival by causing acute antibody-mediated rejection (AAMR). In this article, we report our experiences about the efficiency of plasmapheresis (PP) and intravenous immunoglobulin (IVIG) in reduction of serum PRA levels in candidates for renal transplantation and in patients with AAMR.

METHODS

We examined retrospectively 47 patients with high PRA levels (18 for desensitization (DS) and 29 with AAMR) at Ankara University. The reduction in PRA class 1 and PRA class 2 levels before and after the PP, IVIG, and rituximab or eculizumab therapy were evaluated.

RESULTS

In the DS group, mean reduction in PRA class I ± SD was 28.0 ± 9.10 to 22.1 ± 8.14 (P <.05), and mean reduction in PRA class II ± SD was 40.3 ± 6.89 to 32.2 ± 5.68 (P < .05). In the AAMR group; mean reduction in PRA class I ± SD was 23.9 ± 9.56 to 17.8 ± 8.64 (P > .05), and mean reduction in PRA class II ± SD was 28.1 ± 8.37 to 26.7 ± 7.96 (P > .05). In total, mean reduction in PRA class I was 25.7 ± 6.66 to 19.7 ± 6.00 (P < .01). Mean reduction in PRA class II was 33.8 ± 5.93 to 29.2 ± 4.96 (P > .05). In the DS group, 3 (16.7%) patients were treated with rituximab. In the AAMR group, 9 (31.0%) patients were treated with rituximab, and 1 (5.5%) patient received eculizimab.In the DS group, the mean follow-up period in years ± SD was 5.06 ± 3.01 and no patient had graft loss. In the AAMR group, the mean follow-up period in years was 5.06 ± 2.74 and 6 (33.3%) patients had graft loss with acute rejection.

CONCLUSIONS

PP and IVIG treatment provide significant reduction in PRA levels and can be used in DS protocols.

Infectious complications in living-donor kidney transplant recipients undergoing multi-modal desensitization

BACKGROUND

Pre-existing humoral barriers challenge the transplantation of living donor kidneys (LDK) into highly sensitized ABO- and human leukocyte antigen (HLA)-incompatible recipients. Conditioning these LDK recipients' immune systems is required before they undergo transplantation. We hypothesized that medical desensitization would yield higher post-transplantation rates of infection.

METHODS

We conducted a study in which matched controls consisting of non-desensitized (NDS) LDK recipients were compared with desensitized (DS) receipients. Pre-transplantation desensitization included treatment with rituximab and mycophenolate mofetil followed by intravenous immunoglobulin (IVIg) and plasmapheresis. All participants in the study underwent induction therapy and maintenance immunosuppression. Primary outcomes included infection (opportunistic, local, systemic) within 12 mo after transplantation.

RESULTS

Twenty-five patients underwent desensitization and LDK transplantation. Graft survival in the DS and NDS groups of patients was 96% and 98%, respectively. The mean 3- and 12-mo serum creatinine concentrations in the DS and NDS groups were 1.1±0.2 mg/dL and 1.2±0.3 mg/dL and 0.95±0.4 mg/dL and 0.73±0.8 mg/dL (p=0.3 and p=0.01), respectively. Thirty-six percent of the patients in the DS group had one or more infections, vs. 28% of those in the NDS group (p=0.1). No difference was observed in the frequency of opportunistic or systemic infections in the two groups. Local infections were statistically significantly more frequent in the DS group (60% vs. 30%, respectively; p=0.02).

CONCLUSION

Pre-operative desensitization in highly sensitized LDK recipients is followed by a similar incidence of opportunistic and systemic infections as in NDS patients. Local infections were significantly more frequent in the DS than in the NDS patients in the study. With careful monitoring of infectious complications, pre-transplant desensitization permits LDK transplantation into highly sensitized patients.