Immune monitoring of transplant patients in transient mixed chimerism tolerance trials (original) (raw)
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Transplantation Journal, 2010
Background-We have previously reported operational tolerance in patients receiving HLAmismatched combined kidney and bone marrow transplantation (CKBMT). We now report on transient multilineage hematopoietic chimerism and lymphocyte recovery in five patients receiving a modified CKBMT protocol, and evidence for early donor-specific unresponsiveness in one of these patients. Methods-Five patients with end-stage renal disease received CKBMT from HLA-mismatched, haploidentical living related donors following modified non-myeloablative conditioning. Polychromatic flow cytometry (FCM) was used to assess multilineage chimerism where evaluable and lymphocyte recovery post-transplant. Limiting dilution analysis was used to assess helper-Tlymphocyte reactivity to donor antigens. Results-Transient multilineage mixed chimerism was observed in all patients but chimerism became undetectable by 2 weeks post-CKBMT. A marked decrease in T and B lymphocyte counts immediately following transplant was followed by gradual recovery. Initially recovering T cells were depleted of CD45RA + /CD45RO − "naïve-like" cells, which have shown strong recovery in two patients and CD4/CD8 ratios increased immediately following transplant but then declined markedly. NK cells were enriched in the peripheral blood of all patients following transplant.
2010
Background-We have previously reported operational tolerance in patients receiving HLAmismatched combined kidney and bone marrow transplantation (CKBMT). We now report on transient multilineage hematopoietic chimerism and lymphocyte recovery in five patients receiving a modified CKBMT protocol, and evidence for early donor-specific unresponsiveness in one of these patients. Methods-Five patients with end-stage renal disease received CKBMT from HLA-mismatched, haploidentical living related donors following modified non-myeloablative conditioning. Polychromatic flow cytometry (FCM) was used to assess multilineage chimerism where evaluable and lymphocyte recovery post-transplant. Limiting dilution analysis was used to assess helper-Tlymphocyte reactivity to donor antigens. Results-Transient multilineage mixed chimerism was observed in all patients but chimerism became undetectable by 2 weeks post-CKBMT. A marked decrease in T and B lymphocyte counts immediately following transplant was followed by gradual recovery. Initially recovering T cells were depleted of CD45RA + /CD45RO − "naïve-like" cells, which have shown strong recovery in two patients and CD4/CD8 ratios increased immediately following transplant but then declined markedly. NK cells were enriched in the peripheral blood of all patients following transplant.
Tolerance Induction in HLA Disparate Living Donor Kidney Transplantation by Donor Stem Cell Infusion
Transplantation Journal, 2013
Background. We recently reported that durable chimerism can be safely established in mismatched kidney recipients through nonmyeloablative conditioning followed by infusion of a facilitating cell (FC)-based hematopoietic stem cell transplantation termed FCRx. Here we provide intermediate-term follow-up on this phase II trial. Methods. Fifteen human leukocyte antigenYmismatched living donor renal transplant recipients underwent lowintensity conditioning (fludarabine, cyclophosphamide, 200 cGy TBI), received a living donor kidney transplant on day 0, then infusion of cryopreserved FCRx on day +1. Maintenance immunosuppression, consisting of tacrolimus and mycophenolate, was weaned over 1 year. Results. All but one patient demonstrated peripheral blood macrochimerism after transplantation. Engraftment failure occurred in a highly sensitized (panel reactive antibody [PRA] of 52%) recipient. Chimerism was lost in three patients at 2, 3, and 6 months after transplantation. Two of these subjects had received either a reduced cell dose or incomplete conditioning; the other two had PRA greater than 20%. All demonstrated donor-specific hyporesponsiveness and were weaned from full-dose immunosuppression. Complete immunosuppression withdrawal at 1 year after transplantation was successful in all patients with durable chimerism. There has been no graft-versushost disease or engraftment syndrome. Renal transplantation loss occurred in one patient who developed sepsis following an atypical viral infection. Two subjects with only transient chimerism demonstrated subclinical rejection on protocol biopsy despite donor-specific hyporesponsiveness. Conclusions. Low-intensity conditioning plus FCRx safely achieved durable chimerism in mismatched allograft recipients. Sensitization represents an obstacle to successful induction of chimerism. Sustained T-cell chimerism is a more robust biomarker of tolerance than donor-specific hyporeactivity.
Frontiers in immunology, 2024
Introduction: We investigated the potential role of HLA molecular mismatches (MM) in achieving stable chimerism, allowing for donor-specific tolerance in patients undergoing combined living donor kidney and hematopoietic stem cell transplantation (HSCT). Methods: All patients with available DNA samples (N=32) who participated in a phase 2 clinical trial (NCT00498160) where they received an HLA mismatched co-transplantation of living donor kidney and facilitating cell-enriched HSCT were included in this study. High-resolution HLA genotyping data were used to calculate HLA amino acid mismatches (AAMM), Eplet MM, three-dimensional electrostatic mismatch scores (EMS-3D), PIRCHE scores, HLA-DPB1 T-cell epitope group MM, HLA-B leader sequence MM, and KIR ligands MM between the donor and recipient in both directions. HLA MM were analyzed to test for correlation with the development of chimerism, graft vs. host disease (GvHD), de novo DSA, and graft rejection. Results: Follow-up time of this cohort was 6-13.5 years. Of the 32 patients, 26 developed high-level donor or mixed stable chimerism, followed by complete withdrawal of immunosuppression (IS) in 25 patients. The remaining six of the 32 patients had transient chimerism or no engraftment and were maintained on IS (On-IS). In host versus graft direction, a trend toward higher median number of HLA-DRB1 MM scores was seen in patients On-IS compared to patients with high-level donor/mixed chimerism, using any of the HLA MM modalities; however, initial statistical significance was observed only for the EMS-3D score (0.45 [IQR, 0.30-0.61] vs. 0.24 [IQR, 0.18-0.36], respectively; p=0.036), which was lost when applying the Bonferroni correction. No statistically significant differences between the two groups were observed for AAMM, EMS-3D, Eplet MM, and PIRCHE-II scores calculated in graft versus host direction. No associations were found between development of chimerism and GvHD and non-permissive HLA-DPB1 T-cell epitope group MM, HLA-B leader sequence, and KIR ligands MM.
Immune tolerance in recipients of combined haploidentical bone marrow and kidney transplantation
Bone Marrow Transplantation, 2015
The success of allogeneic hematopoietic cell transplantation (HCT) has been limited by transplant-associated toxicities related to the conditioning regimens used and to graft-vs-host disease (GVHD). The frequency and severity of GVHD observed when extensive HLA barriers are transgressed has greatly impeded the routine use of extensively HLA-mismatched HCT. Allogeneic HCT also has potential as an approach to organ allograft tolerance induction, but this potential has not been previously realized because of the toxicity associated with traditional conditioning. This paper reviews an approach to HCT involving reduced intensity conditioning that demonstrated sufficient safety in patients with hematologic malignancies, even in the HLA-mismatched transplant setting, to be applied for the induction of kidney allograft tolerance in humans with no other indication for HCT. These studies provided the first successful example of intentional organ allograft tolerance induction across HLA barriers in humans. Current data and hypotheses on the mechanisms of tolerance in these patients are reviewed.
Transplantation, 2004
We retrospectively studied the outcome of 213 consecutive patients who received allo-HSCT for hematological malignancies, 121 (57%) from HLA identical siblings, 63 (29%) from 10/10 HLA identical unrelated donors and 29 (14%) from 9/10 HLA mismatched unrelated donors between 2006 and 2011 in our institution. Engraftment was significantly lower in the 9/10 HLA group (90%) than in the 10/10 HLA group (95%) than in the siblings group (99%), (p=0.03). The median OS was 10 months (5-21), 18 months (11-NR) and 60 months (31-NR) respectively with a 2-years probability of 19% (8-44), 43% (31-59) and 63% (54-74) respectively. TRM was significantly higher in the 9/10 HLA group with 1 year cumulative incidence of 45% (35-55), compared to 33% (27-39) in the unrelated 10/10 HLA group and 12% (9-15) in the siblings group (p<0.001). Disease status at transplantation less than first CR/chronic phase was associated with worse OS [HR=3 (1.4-6), p=0.003]. Leuk Lymphoma Downloaded from informahealthcare.com by INSERM on 07/29/14 For personal use only.
Transplantation Journal, 2004
Introduction: The long-term success of ABO incompatible and positive crossmatch kidney transplantation is still unclear. We compared protocol kidney biopsies 1 year after positive crossmatch, ABO incompatible and negative crossmatch/ABO compatible ("conventional") kidney transplants with regard chronic interstitial fibrosis and glomerulopathy. Methods: Patients with at least one year of follow-up were included in this analysis. From 9/2000-3/2003, 25 AHG-CDC positive crossmatch transplants and 23 ABO incompatible transplants were performed. Desensitization consisted primarily of pre-transplant plasmapheresis with splenectomy in the earlier patients. During an overlaping time period, 404 conventional transplants were performed. Immunosuppression consisted of anti-thymocyte globulin induction, tacrolimus, MMF and prednisone. Protocol allograft biopsies were performed at time zero and at 4 and 12 months after transplant and were scored according to Banff '97 criteria. Statistical analyses were performed using Student's t-test and Fisher's exact test. Results: No significant differences were seen in serum creatinine levels between the groups at 4 and 12 months. The results are summarized in Table 1. No significant difference was seen in the rates of patients having a "ci" or "cg" score of zero at any time point when comparing the conventional recipients to either the positive crossmatch or ABO incompatible recipients. During the first year post-transplant, the respective cellular and humoral rejection rates were 12% and 16% in the positive crossmatch transplants, 9% and 17 % in the ABO incompatible transplants, and 4% and 1% in the conventional recipients. The incidence of glomerulopathy was low (Ͻ1%) in all groups. While not statistically significant, there was a trend toward an increase in ci2 or greater fibrosis in recipients of positive crossmatch transplants (33% vs 23% vs 18%). Importantly, more than 1/3 of patients in all groups had no histologic abnormalities at 1 year. Conclusions: Renal allograft histology of recipients of ABOi and ϩXM recipients at one year after transplantation is comparable to that of conventional transplants. Despite a humoral rejection rate of 17% in the antibody groups, the renal function was comparable at 4 and 12 months. While longer follow-up is needed, these intermediate-term results suggest that the ABOi incompatible and positive crossmatch recipients may yet have long-term outcomes similar to conventional transplants.
HLA-Mismatched Renal Transplantation without Maintenance Immunosuppression
New England Journal of Medicine, 2008
Five patients with end-stage renal disease received combined bone marrow and kidney transplants from HLA single-haplotype mismatched living related donors, with the use of a nonmyeloablative preparative regimen. Transient chimerism and reversible capillary leak syndrome developed in all recipients. Irreversible humoral rejection occurred in one patient. In the other four recipients, it was possible to discontinue all immunosuppressive therapy 9 to 14 months after the transplantation, and renal function has remained stable for 2.0 to 5.3 years since transplantation. The T cells from these four recipients, tested in vitro, showed donor-specific unresponsiveness and in specimens from allograft biopsies, obtained after withdrawal of immunosuppressive therapy, there were high levels of P3 (FOXP3) messenger RNA (mRNA) but not granzyme B mRNA.
American Journal of Transplantation, 2011
We recently reported long-term organ allograft survival without ongoing immunosuppression in 4 of 5 patients receiving combined kidney and bone marrow transplantation from haploidentical donors following non-myeloablative conditioning. In vitro assays up to 18 months revealed donorspecific unresponsiveness. We now demonstrate that T cell recovery is gradual and is characterized by memory-type cell predominance and an increased proportion of CD4 + CD25 + CD127 − FOXP3 + Treg during the lymphopenic period. Complete donor-specific unresponsiveness in proliferative and cytotoxic assays, and in limiting dilution analyses of IL-2producing and cytotoxic cells, developed and persisted for the 3-year follow-up in all patients, and extended to donor renal tubular epithelial cells. Assays in 2 of 4 patients were consistent with a role for a suppressive tolerance mechanism at 6 months to 1 year, but later (≥18 months) studies on all 4 patients provided no evidence for a suppressive mechanism. Our studies demonstrate, for the first time, long-term, systemic donor-specific unresponsiveness in patients with HLA
Mechanisms of Mixed Chimerism-Based Transplant Tolerance
Trends in Immunology, 2017
Immune responses to allografts represent a major barrier in organ transplantation. Immune tolerance to avoid chronic immunosuppression is a critical goal in the field, recently achieved in the clinic by combining bone marrow transplantation with kidney transplantation following nonmyeloablative conditioning. At high levels of chimerism, such protocols can permit central deletional tolerance, yet with a significant risk of graft-versus-host disease (GVHD). In contrast, transient chimerism-based tolerance is devoid of GVHD risk and appears to initially depend on regulatory T cells followed by a gradual, presumably peripheral, clonal deletion of donor-reactive T cells. Here, we review recent mechanistic insights into tolerance and the development of more robust and safer protocols for tolerance induction that will be guided by innovative immune monitoring tools.