Splenic Irradiation for the Treatment of Severe Antibody-Mediated Rejection.

Patients requiring desensitization prior to renal transplantation are at risk for developing severe antibody-mediated rejection (AMR) refractory to treatment with plasmapheresis and intravenous immunoglobulin (PP/IVIg). We have previously reported success at graft salvage, long-term graft survival and protection against transplant glomerulopathy with the use of eculizumab and splenectomy in addition to PP/IVIg. Splenectomy may be an important component of this combination therapy and is itself associated with a marked reduction in donor-specific antibody (DSA) production. However, splenectomy represents a major operation, and some patients with severe AMR have comorbid conditions that substantially increase their risk of complications during and after surgery. In an effort to spare recipients the morbidity of a second operation, we used splenic irradiation in lieu of splenectomy in two incompatible live donor kidney transplant recipients with severe AMR in addition to PP/IVIg, rituximab and eculizumab. This novel approach to the treatment of severe AMR was associated with allograft salvage, excellent graft function and no short- or medium-term adverse effects of the radiation therapy. One-year surveillance biopsies did not show transplant glomerulopathy (tg) on light microscopy, but microcirculation inflammation and tg were present on electron microscopy.

Local allograft irradiation as an adjunct for treating severe resistant rejection after liver transplantation in adults.

Acute rejection after liver transplantation occurs in one-third of all recipients and can be managed with conventional rejection therapy in the majority of cases. In rare instances, patients with severe acute rejection may be refractory to or have contraindications for conventional therapies. This case series evaluates the role of local allograft irradiation (LAI) as an adjunct for patients with rejection that is refractory to or contraindicated for conventional therapies. Additionally, the literature on the use of radiation therapy for reversing rejection in solid organ transplantation is reviewed. Five patients underwent 9 LAI treatments: 2 had refractory rejection, and 1 each had a malignancy, a concurrent life-threatening infection, and serum sickness with antibody therapy. Conventional rejection therapies included steroids, calcineurin inhibitors, and antithymocyte globulin. LAI consisted of 3 cycles of 1.5 Gy directed toward the liver allograft. Two of the 5 patients remained alive with excellent graft function. Six of the 9 treatments were successful in rescuing the liver allograft (reversing the rejection episode). Treatment success was associated with lower pretreatment serum bilirubin levels and higher pretreatment alanine aminotransferase levels. Compared with patients with immunosuppression-responsive severe acute rejection, those requiring LAI trended toward a later onset of first rejection. In conclusion, local irradiation of liver allografts can be a useful adjunct in patients for whom conventional options have been exhausted or cannot be used. The ability of LAI to reverse allograft dysfunction and promote patient survival appears to be greatest before the onset of severe cholestatic injury.

Complications of allogeneic hematopoietic stem cell transplantation.

Infection, graft-versus-host disease (GVHD), and to a lesser extent sinusoidal obstructive syndrome (SOS) represent the major causes of morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (AHSCT). During the last decade, progress in prevention and treatment of these complications led to improvement in the outcome of these patients. Despite the fact that nonmyeloablative regimens have been increasingly used in elderly patients and in patients with co-morbidities, the nonrelapse related mortality remains a challenge and long-term follow-up is required. The objective of this manuscript is to provide an updated concise review of the complications of AHSCT and of the available treatment interventions.

Total lymphoid irradiation in heart transplantation: long-term efficacy and survival--an 18-year experience.

BACKGROUND: Total lymphoid irradiation (TLI) has been used in transplantation for over 20 years and is currently used in a number of major heart transplant centers as a secondary therapy for recalcitrant recurrent rejection or rejection with hemodynamic compromise. The purpose of this study is to evaluate the long-term risks and efficacy of TLI in the treatment of rejection. METHODS: Between 1990 and 1996, 73 adult patients (from 211 adult transplant recipients) received TLI for recurrent rejection (71%), rejection with hemodynamic compromise (25%), and rejection with vasculitis (4%). The treatment consisted of 80 cGy twice per week for 5 weeks. Fifty-five patients received at least 80% of the full dose (>640 cGy). Follow-up ended December 31, 2007, comprising a total 18 year experience. RESULTS: Patients treated with TLI exhibited a short-term decrease in hazard for rejection in the first 12 months posttransplantation (relative risk, 0.36) but exhibited increased cumulative rejection over the long term. There were no differences in the rates of infection, allograft coronary disease, or malignancy, but seven patients developed myelodysplasia or acute myelogenous leukemia, four of those being the rare but uniformly fatal acute megakaryocytic leukemia type 7. CONCLUSIONS: Patients treated with TLI seemed to experience a reduction in the early hazard for rejection, but long-term outcomes indicate that such patients continued to accumulate more rejection and rejection-death events, likely because these patients were overall at much higher risk for rejection than the other patient groups. We observed minimal long-term complications, except for the unique occurrence of myelodysplasia and acute megakaryocytic leukemia type 7.

Tailored total lymphoid irradiation in heart transplant patients: 10-years experience of one center.

BACKGROUND: To assess safety and efficacy of tailored total lymphoid irradiation (tTLI) in cardiac transplant patients. METHODS: A total of seven patients, of which five had recalcitrant cellular cardiac allograft rejection (RCCAR), confirmed by endomyocardial biopsies, and two had side effects of immunosuppressive drug therapy, were all treated with tTLI. tTLI was defined by the adjustment of both the fraction interval and the final irradiation dosage both being dependent on the patients general condition, irradiation-dependent response, and the white blood and platelet counts. A mean dose of 6.4 Gy (range, 1.6 - 8.8 Gy) was given. Median follow-up was 7 years (range, 1.8 - 12.2 years). RESULTS: tTLI was well tolerated. Two patients experienced a severe infection during tTLI (pneumocystis jirovecii pneumonia, urosepsis and generalized herpes zoster) and one patient developed a lymphoproliferative disorder after tTLI. The rate of rejection episodes before tTLI was 0.43 episodes/patient/month and decreased to 0.02 episodes/patient/month after tTLI (P < .001). At the end of the observation time, all patients except one were alive. CONCLUSIONS: tTLI is a useful treatment strategy for the management of RCCAR and in patients with significant side effects of immunosuppressive drug therapy. In this series tTLI demonstrated significantly decreased rejection rates without causing relevant treatment-related toxicity.

Effect of FTY720 and ex vivo graft irradiation in rat small bowel transplantation: expression of mucosal addressin cell adhesion molecule-1.

PURPOSE: We performed a semiquantitative analysis of the expression of Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) and gut-associated tissues (GALT) during small bowel graft rejection in the rat to confirm the effect of FTY720 and ex vivo graft irradiation. METHODS: Small bowel transplantations (SBT) were performed from BN rats to LEW rats. Four groups of SBT animals were studied on days 3, 5, and 7 after operations (untreated, FTY720, ex vivo graft irradiation, FTY720+ex vivo graft irradiation). Indirect immunoperoxidase staining was performed against CD4 and MAdCAM-1. The number of CD4-positive cells in the allografts was also analyzed by flow cytometry. RESULTS: The graft survival was prolonged only in the FTY720-treated groups. The SBT allografts treated by FTY720 demonstrated less infiltration, but the ex vivo graft irradiation group did not show any effect on its expression. In the FTY720-treated groups, MAdCAM-1 expression on high endothelial venules (HEVs) in Peyer's patches (PPs) was upregulated and its expression on endothelial cells of vessels in the lamina propria was downregulated in comparison with the allograft group without FTY720. CONCLUSIONS: It is important to prevent the infiltration of CD4-positive cells, the downregulation of MAdCAM-1 expression on HEVs in PPs and the upregulation of MAdCAM-1 expression on endothelial cells of vessels in the lamina propria for the prolongation of graft survival.

Helical tomotherapy for total lymphoid irradiation.

Total lymphoid irradiation is employed in the preparative regimens for allogeneic bone marrow and solid organ transplantation, solid organ transplant rejection, and chronic graft-versus-host disease. Linear accelerator-based radiotherapy, typically involving opposed anteroposterior and posteroanterior beams, has been commonly used; however, extended source-to-skin patient setup and/or field matching are required, and all organs within the beam coverage receive the entire prescribed dose. Megavoltage helical tomotherapy represents a technological advance in terms of both treatment delivery and patient positioning. The continuously rotating multileaf collimated fan beam allows highly conformal coverage of complex target geometries, in turn allowing avoidance of radiosensitive adjacent organs. In addition, the megavoltage computed tomographic scans allow potentially more accurate, targetbased setup verification. The present case report describes tomotherapy-based total lymphoid irradiation in an adult patient with late-onset cardiac transplant rejection. Treatment planning allowed dose minimization to the spinal cord, kidneys, intestinal compartment, and lungs. The patient tolerated treatment well without acute adverse effects, and he is now in early follow-up.

Short-course total lymphoid irradiation for refractory cardiac transplantation rejection.

BACKGROUND: Total lymphoid irradiation (TLI) has been used as an effective therapy for refractory allograft cardiac transplantation rejection. In this study we assessed our short-course TLI regimen for treatment of this condition. METHODS: A short course of TLI (4.5 Gy in 4 fractions) was given to 6 patients with recalcitrant allograft cardiac transplant rejection at the Royal Perth Hospital. RESULTS: Treatment compliance was excellent with most patients having no acute toxicity. With a median follow-up of 25 months, 83% of patients remain alive and disease-free. CONCLUSIONS: To date, no convincing evidence of radiation-related late effects have been documented with TLI. Nonetheless, larger scale trials are required for validation before this approach can be widely incorporated into the current transplantation (Tx) rejection regimen.

Radiotherapy for rejection of renal transplant allografts refractory to medical immunosuppression.

OBJECTIVE: To evaluate the outcome and prognostic factors of patients who underwent local graft irradiation for acute renal allograft rejection refractory to modern immunosuppressive medications. METHODS: From 1996 to 2005, 33 patients received local graft irradiation (LGI), with 3 patients receiving 2 courses of radiation. Graft rejection was diagnosed when a rise in creatinine prompted a renal biopsy that demonstrated acute allograft rejection. Upon failure of medical immunosuppresion to resolve rejection, patients were then referred by the organ transplant team for LGI. The median dose was 800 cGy (range, 600-800 cGy), and was given in 200 cGy fractions generally using AP/PA fields. A retrospective review was conducted to determine dialysis-free survival, defined as the date from initiation of radiation therapy to date of hemodialysis placement, and to analyze potential factors that may predict dialysis free survival. RESULTS: Median follow-up from date of radiation therapy to date of last follow-up was 25 months (range, 0.9-99.4 months). The median time between allograft transplantation and radiation therapy was 17.8 months. For the entire group of patients, 20.6% were alive with a functioning graft. The median dialysis-free survival for the entire group was 3.8 months. The median dialysis-free survival for those patients not on dialysis at time of irradiation versus those patients on dialysis was significantly different (5.6 versus 0 months, P = 0.02). CONCLUSION: In renal allograft transplant recipients who experienced acute rejection episodes refractory to modern chemical immunosuppression, LGI was well tolerated and remains a viable salvage treatment option.

Human cell engraftment after busulfan or irradiation conditioning of NOD/SCID mice.

Human hematopoietic stem cell (HSC) xenotransplantation in NOD/SCID mice requires recipient conditioning, classically achieved by sublethal irradiation. Pretreatment with immunosuppressive and alkylating agents has been reported, but has not been rigorously tested against standard irradiation protocols. Here, we report that treatment of mice with a single dose (35 mg/kg) of Busilvex, an injectable form of busulfan, enables equivalent engraftment compared to 3.5 Gy irradiation. Mice treated with two doses of 25 mg/kg to reduce busulfan toxicity showed increased chimerism. Busulfan conditioning and irradiation resulted in comparable sensitivity of HSC detection as evaluated by limiting dilution analysis.

Liver allograft radiotherapy to treat rejection in children: efficacy in orthotopic liver transplantation and long-term safety.

BACKGROUND: We studied, retrospectively, the efficacy to control rejection and long-term safety of liver allograft radiotherapy (RT) performed in 14 children. Long-term safety data were collected with the prospect of possible use of RT in liver cell transplantation (LCT). METHODS: Immune suppression included cyclosporine, azathioprine and prednisone. In case of intractable rejection, low-dose allograft RT was administered daily for 3 days, and short-term efficacy was evaluated by liver enzyme assays and histology. The long-term outcome was compared with that of 122 patients undergone transplantation and who had similar treatment, but no RT. RESULTS: Survival at 15 years was 71.4% vs 69.7% in the comparison group. In the RT group, rejection control was complete in six of 14 children and partial in two, all being alive and well 14-18 years later. Ten of 14 children had follow-up biopsy. Six children had normal histology and four had mild unspecific fibrosis. The long-term follow-up biopsy in the comparison group showed fibrosis in 42 of 85 children. The incidence of complications was similar in both groups. CONCLUSIONS: This series shows that, such a RT regimen appeared to be efficient and safe as a rescue treatment for acute rejection. Provided that further investigations in animal models show a certain benefit of low-dose irradiation around LCT, such a regimen could be proposed in human liver cell transplant programmes.

Outcome of radiation therapy for renal transplant rejection refractory to chemical immunosuppression.

Twenty consecutive patients with kidney graft rejection refractory to chemical immunosuppression were treated with local irradiation to the transplanted renal graft (3 x 1.5 Gy). Ten patients were complete responders (median follow-up: 47 months). Six patients were partial responders and failed after 1-4 months. Four patients did not respond.

Systemic radioimmunotherapy using a monoclonal antibody, anti-Tac directed toward the alpha subunit of the IL-2 receptor armed with the alpha-emitting radionuclides (212)Bi or (211)At.

To exploit the fact that IL-2 receptors are expressed by T-cells responding to foreign antigens but not by resting T-cells, humanized anti-Tac (HAT) armed with alpha-emitting radionuclides (212)Bi and (211)At was evaluated in a cynomolgus cardiac allograft model. Control graft survival was 8.2+/- 0.5 days compared with 14.0+/-1.3 days (p<0.01) survival for monkeys treated with (212)Bi labeled HAT and 26.7+/-2.4 days survival (p<0.001 versus controls) with (211)At labeled HAT. Thus, (211)At labeled HAT may have application in organ transplantation and in treatment of IL-2 receptor expressing T-cell leukemia.

Psoralen and UVA light: an in vitro investigation of multiple immunological mechanisms underlying the immunosuppression induction in allograft rejection.

Photopheresis (ECP) is a novel immunomodulatory therapy effectively used to treat several T-cell-mediated diseases and to reverse allograft rejection after organ transplantation. It consists of infusion of UVA-irradiated autologous leukocytes collected by apheresis and extracorporeally incubated with 8-methoxypsoralen (8-MOP). In this study we explored the potential immunological events for therapeutic efficacy of photopheresis in preventing allograft rejection by evaluating in vitro the combined effects of 8-MOP and UVA (PUVA) on multiple immunological parameters, such as induction of apoptosis, production of soluble mediators, and expression of cell antigens. Peripheral blood mononuclear cells (PBMCs) obtained from healthy subjects were treated with 8-MOP and UVA at the same doses as those clinically used in ECP. We demonstrate that PUVA treatment induced leukocyte hyporesponsiveness and a decrease in expression of co-stimulatory and adhesion molecules as well as of cytokine levels. Additionally, PUVA treatment induced apoptosis in both mononuclear cells (possibly through the Fas/FasL system and/or the CD38 pathway) and purified monocytes. In conclusion, our work focuses attention on the initial phase of immune response and identifies some new targets of therapy (e.g., costimulatory molecules) able to trigger final effects underlying therapeutic efficacy of photopheresis.

[Radiotherapy within the scope of allogeneic kidney transplantation: an indication for local irradiation?]. / Strahlentherapie im Rahmen der allogenen Nierentransplantation: eine Indikation zur lokalen Bestrahlung?

PURPOSE: In the past decades the indications for local graft irradiation (LGI) in acute renal transplant rejection have been limited and considered unfavorably. Despite major advantages in maintenance immunosuppression and management of acute allograft rejection a minority of patients remains with drug resistant transplant rejection. This subgroup of patients may benefit from LGI. PATIENTS AND METHODS: Between 1979 and 1990, eight patients with biopsy-proven acute renal allograft rejection and failure of all other immunosuppressive measures (corticosteroids, ATG, ALG or OKT3) were treated with LGI. Retrospective analysis was conducted for this control group. Radiotherapy was performed with Co-60 up to a median total dose of 6.0 Gy (single doses: 1.5-2.0 Gy). Six of eight patients were dialysis dependent prior to irradiation. In addition a literature review was performed including most important textbooks, electronic databases (Medline, Embase, Science Citations Index), and the internet. RESULTS: Two of eight patients experienced a clinical reversal of rejection and an improvement of renal function: serum creatinine decreased significantly. One patient remained free of dialysis with a functioning graft, the other had a recurrent rejection 2 months later and became dialysis dependent. The literature review showed, that adjuvant LGI has no advantage over conventional immunosuppression. However, in case of a drug refractory allograft rejection LGI restores long-term stable organ function in 13-60% of cases. CONCLUSION: The value of LGI of organ transplants, like renal allografts, is still not clearly defined. As a rescue measure in drug refractory allograft rejection special patients may clinically benefit, when a transplant nephrectomy can be avoided. Further prospective clinical trials are needed for a better assessment of LGI in organ transplantation.

T cell-mediated tumor rejection displays diverse dependence upon perforin and IFN-gamma mechanisms that cannot be predicted from in vitro T cell characteristics.

Experimental pulmonary metastases have been successfully treated by adoptive transfer of tumor-sensitized T cells from perforin knockout (KO) or Fas/APO-1 ligand(KO) mice, suggesting a prominent role for secretion of cytokines such as IFN-gamma. In the present study we confirmed that rejection of established methylcholanthrene-205 (MCA-205) pulmonary metastases displayed a requirement for T cell IFN-gamma expression. However, this requirement could be obviated by transferring larger numbers of tumor-sensitized IFN-gamma (KO) T cells or by immunosensitizing sublethal irradiation (500 rad) of the host before adoptive therapy. Extrapulmonary tumors (MCA-205 s.c. and intracranial) that required adjunct sublethal irradiation for treatment efficacy also displayed no requirement for host or T cell expression of IFN-gamma. Nonetheless, rejection of MCA-205 s.c. tumors and i.p. EL-4 tumors, but not MCA-205 pulmonary or intracranial tumors, displayed a significant requirement for T cell perforin expression (i.e., CTL participation). The capacity of T cells to lyse tumor targets and secrete IFN-gamma in vitro before adoptive transfer was nonpredictive of the roles of these activities in subsequent tumor rejection. Adoptive therapy studies employing KO mice are therefore indispensable for revealing a diversity of tumor rejection mechanisms that may lack in vitro correlation due to delays in their induction. Seemingly contradictory KO data from different studies are reconciled by the capacity of anti-tumor T cells to rely on alternative mechanisms when treated in larger numbers, the variable participation of CTL at different anatomic locations of tumor, and the apparent capacity of sublethal irradiation to provide a therapeutic alternative to host or T cell IFN-gamma production.

New scoring system identifies kidney outcome with radiation therapy in acute renal allograft rejection.

PURPOSE: To evaluate the role of radiation therapy for acute refractory renal rejection after failure of medical intervention, and to identify risk factors that influence graft survival following radiation therapy. METHODS: Between June 1989 and December 1995, 53 renal transplant recipients (34 men and 19 women) were treated with localized radiation therapy for acute renal allograft rejection. Graft rejection was defined as an increase in serum creatinine with histologic evidence of rejection on renal biopsy. Ninety-one percent were cadaveric transplant recipients. The majority of patients who experienced acute graft rejection initially received corticosteroid therapy, except for 25% who were referred for radiation therapy and steroids for the first rejection. In more recent years, patients with moderate or severe steroid-resistant or recurrent rejection received OKT3, a polyclonal antilymphocyte antibody (ATGAM), tacrolimus (FK506), or mycophenolate mofetil (MMF). Patients who failed to respond to medical treatment were then referred for radiation therapy. Ultrasound was performed for kidney localization. Treatment consisted of a dose of 600 cGy given in 3 or 4 fractions using 6 MV photons, delivered AP or AP/PA. RESULTS: The overall actuarial graft survival from the initiation of RT was 83% at 1 month, 60% at 1 year, and 36% at 5 years. The median follow-up from the date of transplant to the last follow-up was 22 months. The median time from the date of transplant to the initiation of radiotherapy was 3 months, and the median time from the initiation of radiotherapy to the last follow-up was 10 months. Variables evaluated were as follows: human leukocyte antigen matching on HLA-A, HLA-B, and HLA-DR, the transplant panel-reactive antibodies (PRA) at transplantation, number of acute rejection episodes, interval from the date of the transplant to the first rejection, serum creatinine levels at the time of the first radiation treatment, number of transplants, and concomitant immunosuppressive therapy. Independent factors examined by Cox regression modeling were: gender (p = 0.005), creatinine levels (p = 0.000), HLA-DR (p70% (p = 0.014). Each factor was scored using integral coefficients to generate four different groups. The Kaplan-Meier survival analyzed by group produces an interpretable separation of the risk factors for graft loss. CONCLUSIONS: The outcome in patients treated with radiation therapy for acute renal graft rejection can be predicted by a novel scoring system. Patients with scores of three or less are able to achieve 100% renal graft salvage, while patients who have scores of 12 or higher are not able to be salvaged with the current radiation therapy regimen. Future studies should be directed toward identifying more effective treatment for patients who have a high score based on our criteria. The scoring system should be utilized to identify patients at risk who could benefit from radiation therapy. Further study with a randomized trial utilizing this scoring system is needed to confirm the validity of the scoring system in predicting graft survival and the efficacy of radiation in patients who receive radiation therapy for acute graft rejection.

Intermediate term results of total lymphoid irradiation for the treatment of non-specific graft dysfunction after heart transplantation.

BACKGROUND: A proportion of heart transplant recipients develop poor graft function in the absence of cellular infiltrate in endomyocardial biopsies or transplant associated coronary artery disease. The condition has a poor prognosis and its aetiology is poorly understood. We report encouraging intermediate term results with total lymphoid irradiation (TLI) in the management of this condition. METHODS: Eleven adult cardiac transplant recipients who developed severe allograft dysfunction (NYHA class-4) at a median period of 4 months after orthotopic heart transplantation were successfully treated with TLI. Endomyocardial biopsies and coronary angiography were normal in each patient and biventricular failure developed in spite of immunosuppression with Cyclosporin-A, Azathioprine, oral Prednisolone, Cyclophosphamide and intravenous Methylprednisolone therapy. Total lymphoid irradiation was given with standard Mantle and inverted Y-fields over ten treatments to achieve a cumulative dose of 8 Gy. RESULTS: Each patient had a significant improvement in clinical response and in ventricular performance within 2 months of commencing TLI. Nine patients are currently well (four NHYA class-1, five NHYA class-2) at 4-48 (median 26) months following TLI. Two patients died; one from bacterial septicaemia and one as a consequence of chronic renal failure. Three patients developed opportunistic infection which was successfully treated with appropriate antimicrobial agents. An Ebstein-Barr virus associated lymphoproliferative disorder occurred in one patient and was successfully treated by reduction in immunosuppression and high dose Acyclovir. Two patients developed transient bone marrow suppression. CONCLUSION: The intermediate term results of TLI in the management of poor graft function in cardiac transplant recipients with normal endomyocardial biopsies and coronary angiography are encouraging. Although complications of opportunistic infection, bone marrow suppression and lymphoproliferative disorder occurred, treatment was successful in each case.

Single-field total lymphoid irradiation in the treatment of refractory rejection after heart transplantation.

Nine heart transplant recipients were treated with single-field total lymphoid irradiation (TLI) for early (<1 year) or late (>1 year) rejection that was refractory to multiple regimens of immunosuppressive therapy. For patients with early rejection (n = 6), the rejection frequency (rejections/patient/month) decreased from pre-TLI of 1.63 to post-TLI of .02 (p < .001), and for patients with late rejection (n = 3), the rejection frequency decreased from pre-TLI of .23 to post-TLI of .05 (p < .02). The reduced rejection frequencies have been maintained for a mean follow-up of 28.6 (8 to 78) months, and adverse events during or late after TLI were uncommon. Single-field TLI is a safe and effective technique in the management of refractory rejection early or late after heart transplantation.