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2.
Transplant Proc ; 47(6): 1958-65, 2015.
Article in English | MEDLINE | ID: mdl-26293081

ABSTRACT

BACKGROUND: Since the first reported series in 1995, transplantation of lungs recovered through donation after circulatory determination of death (DCDD) has steadily increased. In some European and Australian centers, controlled DCDD accounts for 15% to 30% of all transplanted lungs. Several transplant centers have reported early and midterm outcomes similar to those associated with the use of donors after brain death. Despite these encouraging reports, less than 2% of all lung transplants in the United States are performed using donors after circulatory determination of death. METHODS: An electronic search from January 1990 to January 2014 was performed to identify series reporting lung transplant outcomes using controlled DCDD. Data from these publications were analyzed in terms of donor characteristics, donation after circulatory determination of death protocols, recipients' characteristics, and early and midterm outcomes. RESULTS: Two hundred twenty-two DCDDs were transplanted into 225 recipients. The rate of primary graft dysfunction grade 3 ranged from 3% to 36%. The need for extracorporeal membrane oxygenation support after transplantation ranged from 0% to 18%. The average intensive care unit stay ranged from 4 to 8.5 days and the average hospital stay ranged from 14 to 35 days. Thirty-day mortality ranged from 0% to 11% and 1-year survival from 88% to 100%. CONCLUSION: Under clinical protocols developed and strictly applied by several experienced lung transplant programs, lungs from controlled DCDD have produced outcomes very similar to those observed with brain death donors.


Subject(s)
Brain Death/diagnosis , Lung Transplantation/methods , Tissue Donors/supply & distribution , Tissue and Organ Procurement/organization & administration , Humans , Primary Graft Dysfunction/prevention & control
3.
Transpl Infect Dis ; 7(3-4): 154-7, 2005.
Article in English | MEDLINE | ID: mdl-16390406

ABSTRACT

A 49-year-old woman underwent bilateral lung transplantation for advanced idiopathic pulmonary fibrosis. During the postoperative period she received immunosuppressive medications as well as corticosteroids. Aspergillus fumigatus grew from a sputum sample, and she was treated with nebulized amphotericin. She was discharged on tacrolimus and prednisone. After initially doing well, she required re-hospitalization for treatment of cytomegalovirus and Pseudomonas aeruginosa pneumonia. She was treated with ganciclovir and cefepime and, after a 2-week hospitalization, was discharged. Seven months after transplantation she developed progressive sinusitis, treated with antibiotics and sinus debridement surgery. Aspergillus organisms were recovered and, at the periphery of the tangled masses of Aspergillus hyphae, numerous amebic cysts were also identified, which were morphologically consistent with Acanthamoeba spp. Subsequent electron microscopy and immunofluorescent staining confirmed this impression. She was initially treated with intravenous amphotericin, later changed to voriconazole and caspofungin. Debridement of the sinuses 3 weeks later revealed fungal hyphae but no amebae. Infections with Acanthamoeba have rarely been reported in lung transplantation but have been recognized in bone-marrow and renal transplant patients, and have been lethal in many cases, particularly in patients with immunosuppression due to human immunodeficiency virus infection. More recently, aggressive antimicrobial therapy has resulted in successful outcomes, as discussed herein.


Subject(s)
Acanthamoeba/isolation & purification , Amebiasis/diagnosis , Amebiasis/parasitology , Lung Transplantation/adverse effects , Acanthamoeba/ultrastructure , Animals , Female , Humans , Immunosuppression Therapy , Microscopy, Electron, Transmission , Middle Aged
4.
Dentomaxillofac Radiol ; 32(4): 247-51, 2003 Jul.
Article in English | MEDLINE | ID: mdl-13679356

ABSTRACT

OBJECTIVES: To investigate the effects of oestrogen deficiency on the microarchitecture of trabecular bone in the mandible and the tibia and to test whether they are correlated. METHODS: Twenty-four age-matched Lewis-Brown-Norway female rats underwent surgical intervention either to remove ovaries (ovariectomy, n=12) or to create a complementary control group (sham-operated, n=12). Sixteen weeks later, the animals were sacrificed and the left side of the mandibles and the tibias were scanned with high resolution micro-CT (15 micro m). Multiple morphological measures including the ratio of bone volume/tissue volume, trabecular thickness, trabecular separation and structure model index were obtained from the experimental and control groups. RESULTS: Ovariectomy significantly decreased the ratio of bone volume/soft tissue volume and trabecular thickness, whilst significantly increasing trabecular separation and structure model index in the mandible (P<0.005) and the tibia (P<0.005). There were significant positive correlations between the mandible and the tibia for trabecular separation (r=0.68, P<0.01) and structure model index (r=0.60, P<0.01). CONCLUSIONS: Oestrogen deficiency results in microarchitectural alterations of trabecular bone in both the mandible and the tibia within 16 weeks. The size of marrow spaces and the shape of trabeculae in the mandible correlate with osteoporotic changes in the long bone.


Subject(s)
Estrogens/deficiency , Mandible/diagnostic imaging , Tibia/diagnostic imaging , Animals , Bone Density , Bone Marrow/diagnostic imaging , Bone Marrow/ultrastructure , Female , Growth Plate/diagnostic imaging , Growth Plate/ultrastructure , Mandible/ultrastructure , Osteoporosis/diagnostic imaging , Osteoporosis/pathology , Ovariectomy , Rats , Rats, Inbred BN , Rats, Inbred Lew , Statistics, Nonparametric , Tibia/ultrastructure , Time Factors , Tomography, X-Ray Computed/methods
5.
Transpl Int ; 14(5): 311-9, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11692215

ABSTRACT

Intrathymic (IT) or portal venous (PV) injection of donor antigens has been shown to prolong organ acceptance in low responder rat strain combinations. We determined whether a combination of these strategies would prolong cardiac allograft survival in high responder combinations. Wistar Furth rats received 1 x 10(8) ACI rat bone marrow cells (BMCs) via IT, intravenous (IV), PV, IV + PV, IT + IV or IT + PV route at the time of ACI cardiac transplantation. Without tacrolimus (FK), all grafts were acutely rejected. With FK immunosuppression (1.5 mg/kg per day, I. M., days 0-4), single BMC injection did not increase graft survival beyond 93 days, whereas 70% of grafts survived indefinitely ( > 150 days) when IT and PV BMCs were combined. Animals receiving IT and PV BMCs also had less allograft vasculopathy. Thus, IT and PV injections of donor BMCs under a brief course of FK synergistically improve cardiac allograft survival.


Subject(s)
Bone Marrow Transplantation , Graft Survival/immunology , Heart Transplantation/immunology , Immunosuppressive Agents/therapeutic use , Tacrolimus/therapeutic use , Animals , Immunosuppression Therapy/methods , Male , Rats , Rats, Inbred ACI , Rats, Inbred WF , Time Factors , Transplantation, Homologous
6.
Org Lett ; 3(21): 3277-80, 2001 Oct 18.
Article in English | MEDLINE | ID: mdl-11594813

ABSTRACT

[structure: see text]. A new fluorescent chemosensor for Cu2+ ions was synthesized by modifying the tripeptide glycyl-histidyl-lysine (GHK) with 9-carbonylanthracene via the standard Fmoc solid-phase peptide synthesis method. While significant fluorescence quenching was observed from the molecule upon binding with Cu2+, addition of Fe2+, Co2+, Ni2+, and Zn2+ to the peptide solution caused a minimum fluorescence emission spectral change, indicating a high specificity of this chemosensor for Cu2+ ions. Effects of pH were also investigated.


Subject(s)
Biosensing Techniques , Copper/analysis , Oligopeptides/chemistry , Anthracenes/chemical synthesis , Fluorescence , Hydrogen-Ion Concentration , Metals, Heavy/analysis , Sensitivity and Specificity , Spectrometry, Fluorescence
7.
Ann Thorac Surg ; 72(4): 1306-10, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11603451

ABSTRACT

BACKGROUND: We determined whether a nontoxic CTLA4-Ig-based conditioning regimen effected mixed chimerism and donor-specific tolerance when heart and bone marrow were transplanted simultaneously. METHODS: Fully mismatched rat strain combinations were used. Recipients received total-body irradiation (300 centigrays), bone marrow (10(8) cells), and cardiac transplants from the donor on day 0. Subsequently, recipient animals received CTLA4-Ig (2 mg/kg, every other day, x 5 doses), tacrolimus (1 mg/kg/day; days 0 to 9), and one dose (10 mg) of antilymphocyte serum on day 10. RESULTS: All bone marrow recipients (n = 7) developed mixed chimerism (mean = 25% +/- 9% at 1 year) and accepted cardiac allografts permanently (> 375 +/- 32 days). Recipients that received conditioning regimen but no bone marrow (n = 5) rejected donor hearts within 51 +/- 13 days (p < 0.01). Recipients that accepted heart grafts also permanently accepted (> 180 days) donor-specific skin grafts, but rapidly rejected (< 10 days) third-party skin grafts. CONCLUSIONS: A nontoxic CTLA4-Ig-based conditioning regimen effects mixed chimerism and donor-specific tolerance when heart and bone marrow are transplanted simultaneously. This regimen may have clinical application.


Subject(s)
Antigens, Differentiation/pharmacology , Bone Marrow Transplantation/immunology , Heart Transplantation/immunology , Immunoconjugates , Transplantation Chimera/immunology , Transplantation Tolerance/immunology , Abatacept , Animals , Antigens, CD , Antilymphocyte Serum/pharmacology , CTLA-4 Antigen , Graft Survival/immunology , Humans , Rats , Rats, Inbred ACI , Rats, Inbred WF , Skin Transplantation/immunology
8.
Org Lett ; 3(14): 2201-4, 2001 Jul 12.
Article in English | MEDLINE | ID: mdl-11440579

ABSTRACT

[reaction: see text] The aldol addition of a chiral ethyl ketone enolate bearing an oxygen substituent (OTBS) at the alpha-position proceeds with high internal and relative diastereoselectivities with various achiral aldehydes in good yields. The profound influence of the resident stereogenic center allows for the use of an achiral catalyst, such as HMPA, with minor attenuation in internal stereoselectivity.

10.
Ann Thorac Surg ; 71(5): 1442-7, 2001 May.
Article in English | MEDLINE | ID: mdl-11383780

ABSTRACT

BACKGROUND: A multicenter, randomized, controlled, open-label trial was conducted to evaluate the safety and efficacy of Celsior when used for flush and hypothermic storage of donor hearts before transplantation. METHODS: Heart transplant recipients were randomized to one of two treatment groups in which donor hearts were flushed and stored in either Celsior or conventional preservation solution(s) (control). Study subjects were followed for 30 days after transplantation. RESULTS: A total of 131 heart transplant recipients were enrolled (Celsior, n = 64; control, n = 67). The treatment groups were evenly distributed in donor and recipient base line characteristics. Graft loss rate was lower in the Celsior group on day 7 (3% versus 9%) and on day 30 (6% versus 13%), but the difference was not statistically significant based on 95% confidence interval analysis. No significant difference was measured between the Celsior and control groups in 7-day patient survival (97% versus 94%) and the proportion of patients with one or more adverse events (Celsior, 88%; control 87%) or serious adverse events (Celsior, 38%; control, 46%). Significantly fewer patients in the Celsior group developed at least one cardiac-related serious adverse event (13% versus 25%). CONCLUSIONS: Celsior was demonstrated to be as safe and effective as conventional solutions for flush and cold storage of cardiac allografts before transplantation.


Subject(s)
Cardioplegic Solutions , Cryopreservation , Disaccharides , Electrolytes , Glutamates , Glutathione , Heart Transplantation , Histidine , Mannitol , Organ Preservation , Adult , Aged , Female , Follow-Up Studies , Graft Rejection/mortality , Graft Survival , Humans , Male , Postoperative Complications/mortality , Transplantation, Homologous
11.
Exp Hematol ; 29(4): 534-41, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11301194

ABSTRACT

The toxic dose of irradiation required to achieve stable mixed hematopoietic chimerism is the major limitation to its clinical application in transplantation and other nonmalignant conditions such as hemoglobinopathies. This study examines the additive effect of costimulatory blockage, to our previously described tacrolimus-based conditioning regimen, in further reducing the dose of total-body irradiation to achieve stable mixed chimerism in rats. Fully mismatched, 4- to 6-week-old ACI and Wistar Furth rats were used as donors and recipients, respectively. Recipients were administered CTLA4-Ig 2mg/kg/day (alternate days) in combination with tacrolimus 1 mg/kg/day (daily) from day 0 through day +10, anti-lymphocyte serum 10 mg at day +10 (single dose), and total-body irradiation ranging from 100-600 cGy, prior to bone marrow transplantation (day 0) with 100 x 10(6) of T-cell-depleted bone marrow cells. Levels of donor chimerism were determined over a period of 12 months. The short course of CTLA4-Ig, tacrolimus, and ALS led to dramatic engraftments at reduced doses of irradiation: 100% (5/5) and 93% (13/14) of the animals developed mixed chimerism at 400 cGy and 300 cGy, respectively. At 300 cGy, recipients exhibited durable, multilineage mixed chimerism at 365 days with donor cells ranging from 19-42% (mean 23.4%) with no evidence of graft-vs-host disease. These mixed chimeras exhibited in vitro (mixed lymphocyte reaction) and in vivo (skin grafts) donor-specific tolerance. This study suggests that addition of costimulatory blockade to a tacrolimus-based conditioning regimen reduces the dose of irradiation required to achieve stable multilineage chimerism in rats.


Subject(s)
Antigens, Differentiation/administration & dosage , Antilymphocyte Serum/administration & dosage , Immunoconjugates , Tacrolimus/administration & dosage , Transplantation Chimera , Transplantation Conditioning , Whole-Body Irradiation , Abatacept , Animals , Antigens, CD , Bone Marrow Transplantation , CTLA-4 Antigen , Graft vs Host Disease , Hematopoietic Stem Cells/immunology , Immune Tolerance , Immunomagnetic Separation , Immunosuppressive Agents/administration & dosage , Lymphocyte Culture Test, Mixed , Radiation Dosage , Rats , Rats, Inbred ACI , Rats, Inbred WF , Skin Transplantation/immunology , T-Lymphocytes
14.
Circ Res ; 87(1): 66-72, 2000 Jul 07.
Article in English | MEDLINE | ID: mdl-10884374

ABSTRACT

Although systemic administration of NO donors has been shown to attenuate the development of neointimal hyperplasia in the balloon injury model, this strategy has not been tested in a model of allograft vasculopathy. In this study, we investigated the effect of FK409, a spontaneous NO releaser, on the development of allograft vasculopathy, using a rat aortic transplant model. Thoracic aortas from ACI rats were transplanted heterotopically into the abdominal aorta of Wistar-Furth rats. Postoperatively, recipients received FK409 orally every 8 hours from the day of transplantation to the time of euthanization. Morphometric and immunohistochemical analyses were performed on the aortic grafts 8 weeks after transplantation. Control allografts showed severe neointimal hyperplasia, which consists mainly of alpha-actin-containing vascular smooth muscle cells. The FK409-treated allografts showed a dose-dependent reduction (statistically significant compared with the control) in the neointimal thickness as the dose increased from 1 to 10 mg/kg (thrice per day). However, there was no significant difference in the neointimal thickness between groups treated with 10 and with 20 mg/kg. FK409 treatment (10 mg/kg) caused a significant decrease in DNA synthesis (5-bromo-2-deoxyuridine [BrdU] uptake), an increase in DNA fragmentation (terminal deoxynucleotidyltransferase-mediated uridine nick-end labeling [TUNEL]), and upregulation of Fas expression, in the neointimal vascular smooth muscle cells. These data suggest that FK409 attenuates the allograft vasculopathy in a rat aortic transplant model.


Subject(s)
Aorta/transplantation , Muscle, Smooth, Vascular/drug effects , Nitric Oxide Donors/pharmacology , Nitro Compounds/pharmacology , Animals , Aorta/pathology , Apoptosis/drug effects , Bromodeoxyuridine/metabolism , Cyclosporine/pharmacology , Immunohistochemistry , Male , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , Rats , Rats, Inbred ACI , Rats, Inbred WF , Transplantation, Homologous
15.
Transplantation ; 69(10): 2112-5, 2000 May 27.
Article in English | MEDLINE | ID: mdl-10852607

ABSTRACT

BACKGROUND: Cardiac transplantation has been successfully performed in patients with a history of presumably cured Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). Though the risk of recurrence is a major concern, the long-term influence of prior cancer and cancer therapy on posttransplant outcome has not been previously investigated. METHODS: Questionnaires were sent to 130 cardiac transplant centers in the United States registered with the United Network for Organ Sharing. Data collected included patient demographics; type, stage, and timing of HD/NHL; treatment for HD/NHL; posttransplant immunosuppressive regimen, rejection history, and outcomes; and Epstein-Barr virus status. RESULTS: Thirty-four cardiac transplant recipients with a previous history of HD (n=16) or NHL (n=18) were identified. HD patients averaged 41+/-15 years of age, with a mean disease-free interval of 15+/-9 years at the time of transplantation. NHL patients averaged 42+/-17 years of age with a mean disease-free interval of 10+/-9 years at the time of transplantation. The mean follow-up for the entire group was 50 months (range, 2 days to 136 months), and mean follow-up for the survivors was 67 months (range, 23-136 months). The 1-, 3-, 5-, 7-, and 10-year actuarial survival estimates for the entire group are 77%, 64%, 64%, 64%, and 50%, respectively. Actuarial survival was lower in HD patients (P=0.04) and in patients who had previously undergone splenectomy (P=0.008). Cox regression analysis identified only prior splenectomy (P=0.02) as an independent risk factor for mortality after cardiac transplantation with an adjusted relative risk of 6.2 (1.7-21.9, 95% confidence intervals). CONCLUSIONS: Although the numbers are small, these data strongly suggest that there is an increased mortality risk for cardiac transplant recipients with prior HD who have undergone splenectomy.


Subject(s)
Heart Transplantation , Hodgkin Disease , Lymphoma, Non-Hodgkin , Actuarial Analysis , Disease-Free Survival , Female , Heart Transplantation/mortality , Heart Transplantation/physiology , Hodgkin Disease/mortality , Hodgkin Disease/therapy , Humans , Lymphoma, Non-Hodgkin/mortality , Lymphoma, Non-Hodgkin/therapy , Male , Splenectomy , Surveys and Questionnaires , Survival Analysis , Survivors , Time Factors , United States
16.
Ann Thorac Surg ; 69(2): 345-50, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10735661

ABSTRACT

BACKGROUND: We have demonstrated that donor cell chimerism is associated with a lower incidence of obliterative bronchiolitis (OB) in lung recipients, and that donor chimerism is augmented by the infusion of donor bone marrow (BM). We herein report the intermediate results of a trial combining the infusion of donor BM and lung transplantation. METHODS: Clinical and in vitro data of 26 lung recipients receiving concurrent infusion of donor bone marrow (3.0 to 6.0 x 10(8) cells/kg) were compared with those of 13 patients receiving lung transplant alone. RESULTS: Patient survival and freedom from acute rejection were similar between groups. Of the patients whose graft survived greater than 4 months, 5% (1 of 22) of BM and 33% (4 of 12) of control patients, developed histologic evidence of OB (p = 0.04). A higher proportion (but not statistically significant) of BM recipients (7 of 10, 70%) exhibited donor-specific hyporeactivity by mixed lymphocyte reaction assays as compared with the controls (2 of 7, 28%). CONCLUSIONS: Infusion of donor BM at the time of lung transplantation is safe, and is associated with recipients' immune modulation and a lower rate of obliterative bronchiolitis.


Subject(s)
Bone Marrow Transplantation/immunology , Lung Transplantation/immunology , Transplantation Chimera , Adult , Bronchiolitis Obliterans/etiology , Female , Graft Rejection , Humans , Male , Middle Aged , Prospective Studies , Survival Analysis
17.
J Thorac Cardiovasc Surg ; 119(4 Pt 1): 673-81, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10733755

ABSTRACT

BACKGROUND: Donor chimerism (the presence of donor cells of bone marrow origin) is present for years after transplantation in recipients of solid organs. In lung recipients, chimerism is associated with a lower incidence of chronic rejection. To augment donor chimerism with the aim to enhance graft acceptance and to reduce immunosuppression, we initiated a trial combining infusion of donor bone marrow with heart transplantation. Reported herein are the intermediate-term results of this ongoing trial. METHODS: Between September 1993 and August 1998, 28 patients received concurrent heart transplantation and infusion of donor bone marrow at 3.0 x 10(8) cells/kg (study group). Twenty-four contemporaneous heart recipients who did not receive bone marrow served as controls. All patients received an immunosuppressive regimen consisting of tacrolimus and steroids. RESULTS: Patient survival was similar between the study and control groups (86% and 87% at 3 years, respectively). However, the proportion of patients free from grade 3A rejection was higher in the study group (64% at 6 months) than in the control group (40%; P =.03). The prevalence of coronary artery disease was similar between the two groups (freedom from disease at 3 years was 78% in study patients and 69% in controls). Similar proportions of study (18%) and control (15%) patients exhibited in vitro evidence of donor-specific hyporesponsiveness. CONCLUSIONS: The infusion of donor bone marrow reduces the rate of acute rejection in heart recipients. Donor bone marrow may play an important role in strategies aiming to enhance the graft acceptance.


Subject(s)
Bone Marrow Transplantation , Graft Enhancement, Immunologic , Heart Transplantation , Acute Disease , Cell Transplantation , Female , Graft Rejection/diagnosis , Graft Rejection/prevention & control , Heart Transplantation/adverse effects , Heart Transplantation/immunology , Heart Transplantation/mortality , Histocompatibility Antigens Class I/analysis , Humans , Immunosuppressive Agents/therapeutic use , Lymphocyte Culture Test, Mixed , Male , Middle Aged , Prospective Studies , Transplantation Chimera
18.
J Heart Lung Transplant ; 18(11): 1111-9, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10598735

ABSTRACT

BACKGROUND: In heterotopic heart transplantation, the donor heart is connected parallel to the recipient's diseased heart. Recipients continue to have risks, such as arrhythmia, thromboembolism, valvular heart disease, and ischemic heart disease which can develop in the native heart. It may serve as a clinical model to study long-term pathophysiologic processes in the native heart of patients with a left ventricular assist device. METHOD: We analyzed the prevalence of long-term complications related to the native heart in the heterotopic heart transplant and attempted to gain insight into the potential risk to a native heart after receiving a left ventricular assist device. RESULTS: Between December 1984 and December 1994, 16 patients (13 men, 3 women, ranging in age from 37 to 60 years) underwent heterotopic heart transplant at the University of Pittsburgh. The 1- and 5-year survival rate after the transplant was 81% and 44%, respectively. Actuarial freedom from complications related to the native heart after 1 year and 4 years was ventricular arrhythmia: 85%, 75%; ischemic disease: 85%, 64%; valvular disease: 100%, 88%; and thromboembolism: 85%, 58%. Of these complications, thromboembolism was not considered in determining actuarial freedom from complications because thromboembolism should be regarded as a device-related complication rather than as a native-heart-related complication for left ventricular assist device recipients. Consequently, actuarial freedom from all complications excluding thromboembolism was 70% after 1 year and 50% after 4 years. In addition, the hazard function curve remains constant up to 80 months after the operation without significant differences among the yearly ratios. CONCLUSIONS: This analysis suggests that cautious observation of the native heart's long-term performance is necessary for the left ventricular assist device recipient.


Subject(s)
Heart Transplantation , Heart-Assist Devices/adverse effects , Tachycardia, Ventricular/etiology , Thromboembolism/etiology , Transplantation, Heterotopic , Adult , Cardiac Catheterization , Female , Hemodynamics , Humans , Male , Middle Aged , Prevalence , Prognosis , Retrospective Studies , Risk Factors , Survival Rate , Tachycardia, Ventricular/epidemiology , Tachycardia, Ventricular/physiopathology , Thromboembolism/epidemiology , Thromboembolism/physiopathology , United States/epidemiology
19.
Transplantation ; 68(3): 369-78, 1999 Aug 15.
Article in English | MEDLINE | ID: mdl-10459540

ABSTRACT

BACKGROUND: Mixed allogeneic bone marrow chimerism induces tolerance to solid organ grafts. Although we previously reported that partially ablative conditioning with 700 cGy of total body irradiation (TBI) is sufficient to allow for bone marrow engraftment in mice, we determined that a minimum of 1000 cGy was required in the rat. Because T cells and NK cells are critical in bone marrow graft rejection, our purpose was to examine whether targeting of radioresistant NK cells and/or T cells in the recipient hematopoietic microenvironment would reduce the TBI dose required for engraftment of allogeneic rat bone marrow. METHODS: Wistar Furth rats received either anti-NK3.2.3 monoclonal antibodies on days -3 and -2, anti-lymphocyte serum on day -5, a combination of both or no pretreatment. TBI was performed on day 0 and rats were reconstituted with 100x10(6) T cell-depleted bone marrow cells from ACI donors. RESULTS: Engraftment of T cell-depleted rat bone marrow was readily achieved in animals conditioned with 1000 cGy TBI alone (12/12) and the level of donor chimerism averaged 89%. At 900 cGy TBI alone only one of eight recipients engrafted. In striking contrast, 11 of 12 animals pretreated with anti-NK monoclonal antibodies and irradiated with 900 cGy showed donor chimerism at a mean level of 41%. No further enhancement of bone marrow engraftment could be achieved when recipients were pretreated with antilymphocyte serum alone or antilymphocyte serum plus anti-NK monoclonal antibodies. Mixed allogeneic chimeras exhibited stable multilineage chimerism and donor-specific tolerance to subsequent cardiac allografts. CONCLUSION: Specific targeting of radioresistant host NK cells allows for a significant reduction of the TBI dose required for allogeneic bone marrow engraftment.


Subject(s)
Transplantation Chimera/immunology , Transplantation Conditioning/methods , Animals , Antibodies, Monoclonal/pharmacology , Antilymphocyte Serum/pharmacology , Bone Marrow Transplantation/immunology , Bone Marrow Transplantation/physiology , Graft Rejection/pathology , Graft vs Host Disease/prevention & control , Heart Transplantation/immunology , Immune Tolerance , Killer Cells, Natural/immunology , Killer Cells, Natural/physiology , Killer Cells, Natural/radiation effects , Kinetics , Lymphocyte Depletion , Male , Mice , Rats , Rats, Inbred ACI , Rats, Inbred WF , Whole-Body Irradiation
20.
J Heart Lung Transplant ; 18(6): 532-41, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10395351

ABSTRACT

BACKGROUND: Mixed hematopoietic chimerism has been shown to induce long-term acceptance of transplant organs. We determined whether mixed chimerism prevented allograft vasculopathy, using the rat aortic allograft model. METHODS: Mixed chimeras were prepared by reconstituting lethally irradiated (1100 cGy) WF rats with a mixture of T-cell depleted (TCD) syngeneic (WF) plus TCD allogeneic (ACI) bone marrow. Donor-specific (ACI) or third-party (F344) aortic grafts were transplanted into mixed chimeric animals 1 to 2 months after bone marrow reconstitution. No immunosuppressive drugs were administered. At 30 days postoperatively, aortic allografts were harvested for histology and measurement of cytokine mRNA by semiquantitative RT-PCR. Some aortic grafts were harvested at 90 and 180 days after transplantation for histological analysis. The degree of intimal hyperplasia and cytokine gene expression were compared among 4 groups: I (syngeneic; ACI donors to ACI recipients), II (allografts; ACI to WF), III (donor specific; ACI donor to chimeras) and IV (third-party; F344 to chimeras). RESULTS: There was no difference in the degree of intimal hyperplasia (IH) between groups I and III. Groups II and IV had significantly more IH than group I. Compared to group I, levels of mRNA for IFN-y, IL-2, IL-10 and iNOS in groups II and IV were higher, while there was no difference in mRNA levels between group I and III. CONCLUSIONS: These data suggest that mixed chimerism prevents allograft vasculopathy. Mixed chimerism holds great promise in clinical transplantation as a means to prevent allograft vasculopathy.


Subject(s)
Aorta/transplantation , Bone Marrow Transplantation/immunology , Fibromuscular Dysplasia/immunology , Graft Rejection/immunology , Transplantation Chimera/immunology , Animals , Aorta/pathology , Bone Marrow Transplantation/pathology , Cytokines/genetics , Fibromuscular Dysplasia/pathology , Gene Expression Regulation/physiology , Graft Rejection/pathology , Lymphocyte Depletion , Male , RNA, Messenger/genetics , Rats , Rats, Inbred Strains , Reverse Transcriptase Polymerase Chain Reaction , Transplantation, Homologous
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