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Though tolerance to kidney allografts has been consistently achieved using a mixed chimerism model, cardiac allografts remain resistant to tolerance induction. Lipoprotein-based nanobiologics loaded with a mammalian target of rapamycin inhibiting prodrug (mTOR inhibiting nanobiologics, mTORi-NBs) inhibit trained immunity and promote graft infiltrating M2-macrophages that provide a favorable local immunologic milieu for tolerance induction. In this study, we evaluate the ability of mTORi-NBs to induce tolerance in a cardiac allograft model in NHPs. Six NHPs underwent simultaneous heterotopic heart and bone marrow transplantation for mixed chimerism induction. Group A (n=3) was conditioned with 3 Gy total body irradiation (TBI), 7 Gy thymic irradiation (TI), ATGAM, anti-CD40L monoclonal antibody on days 0, 2, 5,7, 9, and 12 post-bone marrow transplant (pBMTx), and cyclosporine until day 28 pBMTx. Group B recipients (n=3) underwent the same conditioning regimen with the addition of mTORi-NBs at a dose of 0.15 mg/kg on days 2, 5, 12, 19, and 26 pBMTx. Group B donors were also treated with a single dose of mTORi-NBs two days before transplant. In group A, all allografts had end stage rejection by day 175 pBMTx with a mean duration of lymphocyte chimerism of 74 days. The first recipient in group B developed durable full chimerism and mild graft versus host disease (GVHD) which resolved after a course of steroids and cyclosporine. After resolution of his GVHD, his graft continued beating strongly with no evidence of rejection through day 239 pBMTx. The second and third recipients received half dose (1.5 Gy) TBI and both allografts are contracting strongly at days 271 and 26 pBMTx, though the second recipient had some evidence of rejection at day 212 pBMTx. Currently, the mean duration of lymphocyte chimerism in Group B is 149 days. Preliminary studies suggest that adding mTORi-NB nanoimmunotherapy to a mixed chimerism protocol prolongs both donor lymphocyte chimerism and heart graft survival in NHPs even when reducing pre-operative TBI. [ABSTRACT FROM AUTHOR]

Introduction Older adults are a vulnerable road user group with high mortality and morbidity in road crash. The aim of this study was to show pattern of road traffic injuries in this special aging group. Methods and materials In a cross sectional study, pre-hospital emergency system reports, hospital and police records of all motor vehicle collisions injured above 60 years old who were admitted to Pour-Sina hospital from April 2011 to March 2012 were studied. Demographic data, characteristic of road traffic incidents and in-hospital medical profiles were derived. Data were analyzed with SPSS ver. 18. Differences between demographic and injuries situation were calculated by chi square test. A p -value of <0.05 was considered statistically significant. Results One thousand three-hundred six old injured were admitted during study period that this amount accounted for 8.7% of total road accident injured. Mean age of them was 70.9 ± 6.7 years. Most of them were male (74.7%). 40.5% were pedestrians, 22.1% were car occupants and 19.1% were motorcyclists.76.7% had multiple trauma. Head and neck were the most prevalent regions of injured. Total in-hospital mortality rate was 10.1% that was higher in old elderly pedestrians and motorcyclists in comparison to young elderly (16.1% vs. 7.9%) and other type of victims ( ρ < 0.000). Results One thousand three-hundred six old injured were admitted during study period that this amount accounted for 8.7% of total road accident injured. Mean age of them was 70.9 ± 6.7 years. Most of them were male (74.7%). 40.5% were pedestrians, 22.1% were car occupants and 19.1% were motorcyclists.76.7% had multiple trauma. Head and neck were the most prevalent regions of injured. Total in-hospital mortality rate was 10.1% that was higher in old elderly pedestrians and motorcyclists in comparison to young elderly (16.1% vs. 7.9%) and other type of victims ( ρ < 0.000). Conclusion High mortality rate of road traffic injuries in this group especially in pedestrians should be taken into consideration and strategies aimed at the road-user safety including periodic medical examination and improvement of road structure and facilities. [ABSTRACT FROM AUTHOR]

Cardiac allograft tolerance in non-human primates (NHPs) has been achieved by our group using a mixed chimerism model with allogeneic bone marrow transplant after non-myeloablative conditioning but not without kidney co-transplantation. B cell lymphoma 2 (Bcl2) inhibition has allowed for durable mixed chimerism with reduced conditioning in the murine skin transplant model. We investigated whether the Bcl2 inhibitor ABT199 could enhance mixed chimerism and induce cardiac allograft tolerance in the absence of kidney cotransplantation. Fifteen cynomolgus recipients underwent mixed chimerism conditioning (ATGAM, total body and thymic irradiation) then organ and bone marrow transplantation. Group 1 recipients received heart alone (n=5), Group 2 recipients received heart and kidney cotransplants (n=7), and in Group 3, heart recipients received ABT199 in lieu of kidney cotransplants (n=3).Group 1 and 2 received 3Gy total body irradiation (TBI) while Group 3 received 1.5Gy TBI. All recipients underwent a 28-day course of immunosuppression with a calcineurin inhibitor and anti-CD154 mAb after which all immunosuppression was stopped. All five Group 1 recipients demonstrated cellular rejection (ISHLT 3R) by 96 days post bone marrow transplant (pBMTx). In contrast, no Group 2 recipients showed early rejection and 6/7 survived >400 days pBMTx. The first two Group 3 recipients developed GvHD and succumbed by days 59 and 68 pBMTx without evidence of rejection. However, after reducing the size of the donor BMT, the third recipient is now 76 days pBMTx with excellent allograft contractility and no evidence of GVHD. Mean peak lymphoid chimerism was 10% on day 26 pBMTx for Group 1, 26% on day 33 pBMTx for Group 2, and 57% on day 54 pBMTx for Group 3. (Figure 1) After further refinement of the conditioning regimen, ABT199 may allow for the induction of heart allograft tolerance without the need for kidney co-transplantation and with a reduction in TBI thereby improving safety. [ABSTRACT FROM AUTHOR]

Our group has achieved cardiac allograft tolerance in non-human primates (NHPs) via hematopoietic cellular chimerism mediated through allogeneic bone marrow (BM) and kidney co-transplantation after non-myeloablative conditioning. This form of tolerance is believed to rely on the presentation of donor MHC molecules in the host's thymus and peripheral lymphoid tissues (MHC chimerism). Here, we investigated whether allogeneic exosomes instead of donor cells can be used to achieve a similar form of molecular chimerism (via MHC cross-dressing of recipient APCs) in nonhuman primates. Exosomes were isolated through serial ultracentrifugation from donor BM cells expressing the MHC class I epitope H38. Three H38- cynomolgus macaque recipients underwent heart and kidney co-transplantation as part of 2 protocols. In the Simultaneous protocol (n=2), NHPs were conditioned with ATGAM and thymic irradiation, with or without total body irradiation followed by a single dose of exosomes on postoperative day 2. In the Delay protocol (n=1), the NHP received 2 months of triple drug immunosuppression, then was conditioned with ATGAM, aCD8, and ABT199 and received 2 doses of exosomes. All recipients underwent a short course of immunosuppression with a calcineurin inhibitor and anti-CD154 mAb after exosome infusion. Infusion of donor BM derived exosomes resulted in the presence of recipient peripheral blood leukocytes cross-dressed with donor H38 molecules in all animals. Flow cytometric analysis showed MHC class I chimerism restricted to the myeloid compartment. Tissues collected from the Simultaneous group showed H38+ cross-dressed cells present in the lymph nodes, thymus, and spleen. The first Simultaneous protocol NHP died of anemia on postoperative day 33 and the second was sacrificed on postoperative 96 day for cardiac allograft rejection. The Delay protocol NHP is currently 33 days post exosome infusion, showing good contractility of the cardiac allograft by palpation and ultrasound Donor MHC chimerism in the form of MHC cross-dressing can be achieved in a NHP model using donor BM derived exosomes. These findings suggest that BM derived exosomes could be used in place of whole bone marrow in chimerism-induced allograft tolerance protocols. Exosome use could allow reduction of recipient conditioning while eliminating the risk of GVHD. [ABSTRACT FROM AUTHOR]

Cardiac allograft tolerance in non-human primates (NHPs) has been achieved by our group via hematopoietic mixed chimerism with allogeneic bone marrow and kidney co-transplantation. This model has failed without the regulatory mechanisms associated with the donor kidney. We hypothesized that rapamycin and anti-OX40L mAb (KY1005, Kymab Ltd) could substitute for kidney co-transplantation and induce cardiac allograft tolerance by providing a favorable immunologic milieu for regulatory T cells (Tregs). Fourteen cynomolgus NHPs underwent mixed chimerism conditioning (ATGAM, total body and thymic irradiation) then organ and bone marrow transplant. Heart Alone recipients received a heart transplant (n=5), Heart/Kidney recipients received a heart and kidney co-transplant (n=7). Heart/OX40L recipients received a heart transplant plus 40 days of anti-OX40L mAb (n=2). All groups underwent a 12 day course of aCD154 mAb. The Heart Alone and Heart Kidney groups received 28 days of cyclosporine while the Heart aOX40L group received 100 days of rapamycin. All Heart Alone recipients had cellular rejection (ISHLT 3R) by 200 days post bone marrow transplant (pBMT). No Heart/Kidney recipients showed early rejection. Similarly, no Heart/OX40L recipients showed early rejection and one is currently 258 days pBMT without clinical or pathologic evidence of rejection (Figure 1). The other recipient died of viral complications. Mean peak lymphoid chimerism was 10% for the Heart Alone group, 26% for the Heart/Kidney group, and 29% for the Heart/OX40L group. The anti-OX40L protocol also showed an expansion of the Treg population with a peak of 35% Tregs in the CD4+ population. The OX40L protocol achieved robust lymphoid chimerism with concomitant expansion of Tregs. The surviving Heart/OX40L recipient achieved longer freedom from allograft rejection when compared to the Heart Alone group. OX40L costimulatory blockade may allow for heart allograft tolerance without kidney co-transplantation. [ABSTRACT FROM AUTHOR]

In contrast to kidney allografts, attempts to achieve tolerance of isolated cardiac allografts in non-human primates (NHPs) using a mixed chimerism strategy have been unsuccessful. IL-6 is a pro-inflammatory cytokine known to play an important role in allograft rejection. We investigated whether adding anti-IL-6R therapy to our mixed chimerism protocol would enable the induction of tolerance in NHP recipients of MHC mismatched heart allografts. Ten cynomolgous NHPs underwent heart and bone marrow transplantation (BMTx) with non-myeloablative conditioning including total body and thymic irradiation, ATGAM, anti-CD154 mAb, and cyclosporine until post-operative day (POD) 28, with or without anti-IL-6R therapy (tocilizumab, 10 mg/kg IV on POD 0, 7, 14, 21, 28, 56, 84). Group A (n=2) received allogeneic BMTx without anti-IL-6R therapy, Group B (n=6) received allogeneic BMTx with anti-IL-6R therapy, and Group C (n=2) received autologous BMTx with anti-IL-6R therapy. In Group A, both recipients experienced allograft failure due to rejection on POD 104 and 132 [Table]. In Group B, 3 recipients achieved long-term cardiac allograft survival of >400 days off immunosuppression; one recipient is ongoing at POD 360. Two rejected on POD 169 and 383. For Groups A and B, peak lymphocyte chimerism was 10.1% and 18.1%, respectively and duration of lymphocyte chimerism was 57 and 178 days, respectively. In Group C, one recipient rejected on POD 131 and one is ongoing at POD 120. There was no significant difference in magnitude of peripheral T reg expansion between groups (p=0.77). Compared to Group A, Groups B and C had lower CRP levels (mean 12.3 vs 54.3 μg/mL) and higher free serum IL-6 (mean 23.0 vs <7.7 pg/mL) while receiving anti-IL-6R therapy. Tolerance of cardiac allografts has been achieved for the first time in NHPs using a combination of IL-6 signaling blockade and mixed chimerism. This approach represents significant progress towards clinical cardiac allograft tolerance. [ABSTRACT FROM AUTHOR]

Long-term, immunosuppression-free allograft survival has been induced in human and nonhuman primate (NHP) kidney recipients after nonmyeloablative conditioning and donor bone marrow transplantation (DBMT), resulting in transient mixed hematopoietic chimerism. However, the same strategy has consistently failed in NHP heart transplant recipients. Here, we investigated whether long-term heart allograft survival could be achieved by cotransplanting kidneys from the same donor. Cynomolgus monkeys were transplanted with heart allografts alone or heart and kidney allografts from the same major histocompatibility complex (MHC)-mismatched donors. All animals except one received DBMT, either at the same time or after a 2- to 4-month delay, plus short-term costimulation blockade and calcineurin inhibitor treatment. Long-term, immunosuppression-free heart allograft survival was consistently achieved in heart/kidney, but not heart-alone, recipients. This was not associated with greater donor/recipient histocompatibility or altered lymphoid cell reconstitution after conditioning. The maintenance of tolerance after heart/kidney transplantation was associated with the presence of forkhead box P3 (Foxp3 + ) regulatory T cell (T reg )-rich organized lymphoid structures in kidneys but not hearts. Substituting high-dose erythropoietin treatment for kidney transplantation was unsuccessful, suggesting that it was not the sole mechanism of action. RNA sequencing analysis revealed that gene expression in hearts from tolerant recipients closely resembled that in hearts from chronically immunosuppressed recipients but differed markedly from rejecting allografts and naïve hearts. A version of this protocol may be able to induce tolerance in patients with end-stage heart and kidney failure who require combined heart and kidney transplantation.

The thymus is a rich source of regulatory T cells and plays a role in self-tolerance. Therefore, transplantation of a vascularized donor thymus may facilitate the induction of tolerance in recipients of a cotransplanted heart allograft. To investigate this hypothesis, we developed a new technique to procure the heart and thymus en bloc from juvenile donors and transplant the composite allograft into thymectomized recipients. Thymic function was monitored by serial biopsy and flow cytometry of peripheral blood. Heart-thymus en bloc transplantation resulted in immediate revascularization of the heart and donor thymus with maintenance of normal thymic architecture, even in biopsies taken months after transplantation. Heart-thymus en bloc transplantation requires minimal modification to current heart procurement techniques. Here, we describe the details of the preparation, procurement, transplantation, and postoperative monitoring for this model, with the intention that this technique could be implemented by other investigators to study the effects of heart and thymus cotransplantation. This method could ultimately offer a new approach to tolerance induction in children., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

The blockade of the CD154-CD40 pathway with anti-CD154 monoclonal antibody has been a promising immunomodulatory approach to prevent allograft rejection. However, clinical trials of immunoglobulin G1 antibodies targeting this pathway revealed thrombogenic properties, which were subsequently shown to be mediated by crystallizable fragment (Fc)-gamma receptor IIa-dependent platelet activation. To prevent thromboembolic complications, an immunoglobulin G4 anti-CD154 monoclonal antibody, TNX-1500, which retains the fragment antigen binding region of ruplizumab (humanized 5c8, BG9588), was modified by protein engineering to decrease Fc binding to Fc-gamma receptor IIa while retaining certain other effector functions and pharmacokinetics comparable with natural antibodies. Here, we report that TNX-1500 treatment is not associated with platelet activation in vitro and consistently inhibits kidney allograft rejection in vivo without clinical or histologic evidence of prothrombotic phenomena. We conclude that TNX-1500 retains efficacy similar to that of 5c8 to prevent kidney allograft rejection while avoiding previously identified pathway-associated thromboembolic complications., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Hematopoietic stem cell transplantation (HSCT) has many potential applications beyond current standard indications, including treatment of autoimmune disease, gene therapy, and transplant tolerance induction. However, severe myelosuppression and other toxicities after myeloablative conditioning regimens have hampered wider clinical use. To achieve donor hematopoietic stem cell (HSC) engraftment, it appears essential to establish niches for the donor HSCs by depleting the host HSCs. To date, this has been achievable only by nonselective treatments such as irradiation or chemotherapeutic drugs. An approach that is capable of more selectively depleting host HSCs is needed to widen the clinical application of HSCT. Here, we show in a clinically relevant nonhuman primate model that selective inhibition of B cell lymphoma 2 (Bcl-2) promoted hematopoietic chimerism and renal allograft tolerance after partial deletion of HSCs and effective peripheral lymphocyte deletion while preserving myeloid cells and regulatory T cells. Although Bcl-2 inhibition alone was insufficient to induce hematopoietic chimerism, the addition of a Bcl-2 inhibitor resulted in promotion of hematopoietic chimerism and renal allograft tolerance despite using only half of the dose of total body irradiation previously required. Selective inhibition of Bcl-2 is therefore a promising approach to induce hematopoietic chimerism without myelosuppression and has the potential to render HSCT more feasible for a variety of clinical indications.

Background: In kidney transplantation, long-term allograft acceptance in cynomolgus macaques was achieved using a mixed-chimerism protocol based on the clinically available reagents, rabbit anti-thymocyte globulin (ATG), and belatacept. Here, we have tested the same protocol in cynomolgus macaques transplanted with fully allogeneic lung grafts., Methods: Five cynomolgus macaques underwent left orthotopic lung transplantation. Initial immunosuppression included equine ATG and anti-IL6RmAb induction, followed by triple-drug immunosuppression for 4 mo. Post-transplant, a nonmyeloablative conditioning regimen was applied, including total body and thymic irradiation. Rabbit ATG, belatacept, anti-IL6RmAb, and donor bone marrow transplantation (DBMT) were given, in addition to a 28-d course of cyclosporine. All immunosuppressant drugs were stopped on day 29 after DBMT., Results: One monkey rejected its lung before DBMT due to AMR, after developing donor-specific antibodies. Two monkeys developed fatal post-transplant lymphoproliferative disorder, and both monkeys had signs of cellular rejection in their allografts upon autopsy. The remaining 2 monkeys showed severe cellular rejection on days 42 and 70 post-DBMT. Cytokine analysis suggested higher levels of pro-inflammatory markers in the lung transplant cohort, as compared to kidney recipients., Conclusion: Although the clinically applicable protocol showed success in kidney transplantation, the study did not show long-term survival in a lung transplant model, highlighting the organ-specific differences in tolerance induction., Competing Interests: W.S. received funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) -SO 1519/1-1. The other authors declare no conflicts of interest., (Copyright © 2021 The Author(s). Transplantation Direct. Published by Wolters Kluwer Health, Inc.)

Background: We have previously reported successful induction of renal allograft tolerance in nonhuman primates (NHP) after an initial posttransplant period of conventional immunosuppression (delayed tolerance) using a nonmyeloablative conditioning regimen consisting of anti-CD154 and anti-CD8 mAbs plus equine antithymocyte globulin (Atgam) and donor bone marrow transplantation (DBMT). Because these reagents are not currently clinically available, the protocol was revised to be applicable to human recipients of deceased donor allografts., Method: Four cynomolgus monkeys received major histocompatibility complex-mismatched kidney allografts with conventional immunosuppression for 4 months. The recipients were then treated with a nonmyeloablative conditioning regimen consisting of thymoglobulin, belatacept, and DBMT. The results were compared with recipients treated with conditioning regimen consisting of Atgam and anti-CD154 mAb, with and without anti-CD8 mAb., Results: In 4 consecutive NHP recipients treated with the modified conditioning regimen, homeostatic recovery of CD8 TEM was delayed until after day 20 and multilineage chimerism was successfully induced. Three of the 4 recipients achieved long-term allograft survival (>728, >540, >449 days) without ongoing maintenance immunosuppression. Posttransplant MLR showed loss of antidonor CD8 T cell and CD4 IFNγ responses with expansion of CD4FOXP3 regulatory T cells. However, the late development of donor-specific antibody in NHP recipients confirms the need for additional anti-B-cell depletion with agents, such as rituximab, as has been shown in our clinical trials., Conclusions: This study provides proof of principle that induction of mixed chimerism and long-term renal allograft survival without immunosuppression after delayed DBMT is possible with clinically available reagents.

The lack of a reliable immunosuppressive regimen that effectively suppresses both renal and islet allograft rejection without islet toxicity hampers a wider clinical application of simultaneous islet-kidney transplantation (SIK). Seven MHC-mismatched SIKs were performed in diabetic cynomolgus monkeys. Two recipients received rabbit antithymocyte globulin (ATG) induction followed by daily tacrolimus and rapamycin (ATG/Tac/Rapa), and five recipients were treated with anti-CD40 monoclonal antibody (mAb) and rapamycin (aCD40/Rapa). Anti-inflammatory therapy, including anti-interleukin-6 receptor mAb and anti-tumor necrosis factor-α mAb, was given in both groups. The ATG/Tac/Rapa recipients failed to achieve long-term islet allograft survival (19 and 26 days) due to poor islet engraftment and cytomegalovirus pneumonia. In contrast, the aCD40/Rapa regimen provided long-term islet and kidney allograft survival (90, 94, >120, >120, and >120 days), with only one recipient developing evidence of allograft rejection. The aCD40/Rapa regimen was also tested in four kidney-alone transplant recipients. All four recipients achieved long-term renal allograft survival (100% at day 120), which was superior to renal allograft survival (62.9% at day 120) with triple immunosuppressive regimen (tacrolimus, mycophenolate mofetil, and steroids). The combination of anti-CD40 mAb and rapamycin is an effective and nontoxic immunosuppressive regimen that uses only clinically available agents for kidney and islet recipients., (© Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Subcutaneous emphysema (SE) is a condition often causing minimal symptoms, but sometimes it can be severe and even life-threatening. This study is the first great survey about SE. The aim of this study is to classify and evaluate the etiology, signs, symptoms, and management of SE. This retrospective study was performed by reviewing patients who had been diagnosed as having SE in Rasht, between January 2001 and January 2011. We classified the severity of SE in five grades including the (1) base of the neck, (2) all of the neck area, (3) subpectoralis major area, (4) chest wall and all of the neck area, and (5) chest wall, neck, orbit, scalp, abdominal wall, upper limbs, and scrotum. We excluded all patients in grades 1 and 2, because the symptoms and signs were not significant. Statistical analysis was carried out with SPSS 18. We collected 35 cases of SE with the mean age of 53 ± 14.83 (71 % men). The most common cause of SE was pneumothorax with background of COPD and surgery in grade 5, trauma due to rib fracture in grade 4, and iatrogenicity in grade 3. We performed two bilateral 2-cm infraclavicular incisions. In our patients with infraclavicular incisions, expansion of the lung was better, and the patients' appearance improved. Infraclavicular incisions as a simple method for the management of SE can decrease the severity of SE with no cosmetic problem.