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(Chest. 2005;128:4024-4029.)
© 2005 American College of Chest Physicians

Simultaneous Donor Marrow Cell Transplantation With Reduced Intensity Conditioning Prevents Tracheal Allograft Obliteration in a Bronchiolitis Obliterans Murine Model*

Samir Nusair, MD; Reuven Or, MD; Samer Junadi, DMD; Gail Amir, MBChB and Raphael Breuer, MD

* From the Lung Cellular and Molecular Biology Laboratory (Drs. Nusair, Junadi, and Breuer), Institute of Pulmonology; the Cancer Immunobiology Research Laboratory (Dr. Or), Department of Bone Marrow Transplantation; and the Department of Pathology (Dr. Amir), Hadassah-Hebrew University Medical Center, Jerusalem, Israel.

Correspondence to: Samir Nusair, MD, Institute of Pulmonology, Hadassah University Hospital, PO Box 12072, Jerusalem, Israel, 91120; e-mail: samjack{at}shani.net


   Abstract
TOP
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Study objectives: Prolonged survival of transplanted kidney or liver allografts has been associated with prolonged chimerism resulting from donor-origin leukocytes carried within the allograft parenchyma. The present study, performed in a murine model, examined whether simultaneous administration of donor bone marrow cells after reduced intensity conditioning allows acceptance of heterotopic tracheal allografts and prevents the formation of the airway fibroproliferative lesion, which mimics bronchiolitis obliterans (BO).

Methods: Allogeneic tracheal allografts from C57BL/6 mice were grafted subcutaneously into BALB/c mice (n = 6) [day 0]. Conditioning consisted of total lymphoid irradiation (200 cGy) at day – 1, donor marrow cells (3 x 107) administered IV on day 0, intraperitoneal cyclophosphamide (200 mg/kg) on day 1 to eliminate alloreactive marrow cells, followed by a repeated dose of donor marrow cells on day 2. Control groups consisted of one group (n = 4) that underwent similar conditioning without donor marrow cells, and another group (n = 4) that received syngeneic BALB/c marrow cells. None of these groups were administered maintenance immunosuppression. Grafts were harvested and histopathology findings were evaluated semiquantitatively at day 28, day 55, and day 95.

Results: Tracheal allografts from donor marrow cell recipients still maintained a patent airway with intact airway epithelium at 95 days after transplant. However, grafts from control animals not receiving donor marrow cells or mice administered syngeneic marrow cells had lumen obliteration by 28 days after transplant. Chimerism in animals receiving allogeneic bone marrow was confirmed. Graft vs host disease did not develop in animals receiving allogeneic marrow cells.

Conclusions: Further investigation may verify this approach to be applicable for the prevention of posttransplantation BO.

Key Words: airway fibroproliferative lesion • bone marrow transplantation • cyclophosphamide • immune tolerance • lung transplantation • murine model • total lymphoid irradiation • tracheal transplantation


   Introduction
TOP
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
The long-term outcome of lung transplantation has been disappointing, with 3-year actuarial survival of lung transplant patients at 50 to 60%.1 Mortality is largely caused by chronic graft rejection manifesting as bronchiolitis obliterans (BO) and adverse effects of the augmented immunosuppression required to control this process. Newer immunosuppressive drugs have reduced the incidence of acute rejection, but their effect on the occurrence of chronic rejection is still unclear.2 Rescue immunosuppressive interventions such as the administration of cytolytic therapy3 or total lymphoid irradiation (TLI)4 help control acute rejection and at best provide a temporary slowing of forced expiratory airflow volumes decline, but have not shown beneficial effects to reverse the progressive obstructive airway defects in established BO.

Experimental systems have been designed to attempt induction of "central" transplantation tolerance by forming stable mixed chimerism. This approach is based on observations of permanent chimerism following solid-organ transplantation in patients with long-term acceptance of liver and kidney allografts.56 Donor-origin leukocytes carried within the parenchyma of the graft survived and were evidently circulating in the peripheral blood of the recipients starting 3 to 6 months after transplantation.7 However, there was no correlation between the degree of such chimerism and long-term graft survival.78

Induction of specific unresponsiveness to donor alloantigens in mice has been achieved in conjunction with bone marrow transplantation (BMT) following nonmyeloablative conditioning from the graft donor, allowing engraftment of donor skin grafts transplanted 3 weeks later.9 The tolerance induction regimen consisted of low-dose TLI followed by infusion of non–T-cell-depleted bone marrow cells (BMCs), with subsequent administration of cyclophosphamide to eliminate host alloreactive cells and thus allow survival of donor grafts.

Induction of mixed chimerism by BMT preceded by myeloablative conditioning has been shown to allow acceptance and prevent the formation of airway fibroproliferative lesions in experimental lung10 and tracheal graft11 transplant models. In these experiments, tracheal and pulmonary grafts were performed at 4 to 6 weeks after marrow transplant to allow time for hematopoietic reconstitution. The present study was conducted in a murine model of posttransplant BO12 to examine the effectiveness of simultaneous administration of donor marrow cells with tracheal allograft transplantation after nonmyeloablative conditioning in facilitating engraftment of tracheal airway tissue.

Preliminary observations from our laboratory and earlier published studies1213 of this rodent model show that if no immune suppression is administered, heterotopic tracheal allografts transplanted subcutaneously are rejected with marked inflammatory activity evident at day 10 after transplant; and by day 28 there is fibrosis with near-total obliteration of the lumen, similar to changes in small airways detected in posttransplant BO. We hypothesized that this reduced intensity regimen would be well tolerated by recipient animals, and that this conditioning without maintenance immunosuppression would not be associated with graft vs host disease (GVHD) because of the coexistence of recipient and donor BMCs counterbalancing each other.


   Materials and Methods
TOP
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Animals
Inbred, 10- to 12-week-old, female BALB/c (H2d) and C57BL/6 (H2b) mice were supplied by Harlan Sprague Dawley (Indianapolis, IN) and kept under standard conditions with food and water ad libitum in the Hebrew University Hadassah Medical School Animal Facility, Jerusalem, Israel.

C57BL/6 donor mice were used to obtain tracheal grafts and BMCs, while BALB/c mice served as recipients. The experimental protocol was reviewed and approved by the institutional ethical committee for animal use in experimentation.

Donor Mice and Preparation of the Tracheal Graft
Each tracheal graft was obtained after the donor C57BL/6 mouse was euthanized by intraperitoneal thiopental sodium overdose (6 mg in 0.1mL), and the tracheal graft was obtained as previously described12 and then submerged in solution containing penicillin G (100 U/mL), streptomycin sulfate (100 µg/mL), and amphotericin B (0.25 µg/mL) [Euro-Collins; Gibco; Grand Island, NY] until implantation within 10 min after excision.

Recipient Mice
Each allogeneic C57BL/6 tracheal graft was implanted into a subcutaneous pocket in a recipient BALB/c mouse by creating a small skin incision and using 3–0 nylon sutures, under anesthesia obtained by intraperitoneal injection of ketamine: dehydrobenzperidol (10:1) solution at a volume of 0.08 mL containing 0.4 mg of ketamine.

Preparation of BMCs
After euthanization of the donor C57BL/6 mice (or BALB/c in syngeneic transplants), both femurs and tibiae were removed using sterile precautions and BMCs flushed out of the bone into phosphate-buffer solution. Approximately 3 x 107 BMCs in 0.2 mL of phosphate-buffered saline medium were injected into the lateral tail vein of each recipient animal.

TLI
Recipients were anesthetized for proper positioning in an apparatus designed to expose the major lymph nodes, thymus, and spleen to ionizing irradiation, while shielding most of the skull, ribs, lungs, hind limbs, and tail with lead as previously described.14 Radiation was delivered using a radiograph unit (Philips) [250 kilovolts, 20 mA] at a rate of 70 cGy/min, with a Cu 0.2-mm filter. The source-to-skin distance was 40 cm.

Conditioning Protocol and Study Design
The conditioning protocol of the experimental animals before airway grafting was adapted and modified from a previously described protocol from our institution8 and consisted of TLI (a single exposure of 200 cGy), performed 1 day before tracheal implantation, followed by IV inoculation of 3 x 107 allogeneic BMCs administered on the same day of tracheal grafting (day 0). One day later (day 1), an intraperitoneal injection of 200 mg/kg of cyclophosphamide was administered. An additional dose of 3 x 107 donor BMCs was administered 1 day after administration of cyclophosphamide (day 2) to further improve the chimerism level. One control group received the same conditioning without administration of allogeneic BMCs, and the other received syngeneic BMCs (BALB/c source) in order to control for factors that may be related to BMC ablation and reconstitution.

Recipient BALB/c mice were observed daily and weighed weekly until euthanasia. Mice were allocated to experimental and control groups randomly. Tracheal grafts were obtained on day 28 and day 55 at time points when the fibroproliferative would have been fully developed in untreated allografts, and at day 95, at which time long-term graft acceptance could be verified.

Tracheobronchial Graft Harvesting and Specimen Preparation for Histopathologic Examination
Euthanasia of recipient BALB/c donors was performed under deep intraperitoneal thiopental sodium overdose anesthesia, and the tracheal graft was dissected from the subcutaneous pocket and fixed overnight using 4% formalin and 1% glutaraldehyde in 0.1 mol/L cacodylate buffer at pH 7.4. Three 1- to 2-mm transverse sections of each tracheal graft were embedded in paraffin. Paraffin tissue blocks were cut to provide 4- to 6-µm-thick sections. Sections were then stained with hematoxylin-eosin.

Quantitative Assessment of Pathologic Findings
Based on previously described morphologic assessment of fibroproliferative airway lesions in rats,13 two main pathologic processes were assessed and scored semiquantitatively, without knowledge of treatment groups, using a grading scale of 0 to 4, as follows: (process 1) luminal obliteration due to granulation tissue formation and/or fibrosis: 0, no change; 1 +, < 25% obliteration; 2 +, 25 to 50% obliteration; 3 +, 50 to 75% obliteration; 4 +, > 75% obliteration; (process 2) changes (metaplasia or loss) of normal respiratory epithelial lining: 0, no change; 1 +, < 25% circumference change; 2 +, 25 to 50% circumference change; 3 +, 50 to 75% circumference change; 4 +, > 75% circumference change.

Splenic Cell Extraction and Evaluation of Chimerism by Flow Cytometry Analysis
Chimerism was evaluated by determining the percentage of donor-type splenic cells, which represent peripheral blood donor chimera of host animals, using fluorescence-activated cell sorting (FACS) analysis. Lymphocytes were obtained from host animal spleens receiving allogeneic BMCs, placed in phosphate-buffered saline medium, and washed twice. A total of 3.5 x 105 cells were washed with FACS medium and incubated on ice for 45 min with 100 µL of FACS medium containing 1 µg of anti H-2Db-fluorescein isothiocyanate antibodies (Serotec). Cells were then washed and analyzed by flow cytometry (FACStar; Becton Dickinson; Mountain View, CA). To measure background false staining, additional tubes containing host cells unstained with the antibody were added.

Statistical Analysis
Semiquantitative morphologic assessments were compared using Mann-Whitney U test,15 with determination of two-tailed p values. Differences were considered important at p < 0.05. Statistical analysis was performed using statistical software (Prism 3.0; GraphPad).


   Results
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Histopathologic examination of C57BL/6 tracheal grafts obtained at day 28 from the BALB/c recipient control group (n = 6), which received conditioning with TLI and cyclophosphamide but no donor source BMCs, showed allograft rejection. Tracheal allograft lumen changes ranged from minimal encroachment on the lumen to near-total occlusion of the allograft lumen by fibrovascular tissue. This was accompanied by epithelial cell changes ranging from squamous metaplasia and hyperkeratosis to monolayer flattening of surface epithelium, necrosis with desquamation of epithelial cells, or replacement of the epithelial layer with granulation tissue. However, tracheal grafts obtained from the experimental group (n = 6) that received donor allogeneic C57BL/6 BMCs maintained patent tracheal allograft lumen and integrity of the lining epithelium.

Semiquantitative assessments of the morphologic indexes at day 28 are presented in Figure 1 , top, A. The median score of tracheal lumen evaluation was + 3 in control animals, compared to 0 in donor BMC recipients (p = 0.015). The median score of airway epithelial cell evaluation from the experimental animals was + 1.5, reflecting minimal residual abnormalities related to the transplant procedure, while the control group had a median score of + 4 (p = 0.093).



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  		Figure 1. Scores of histopathology semiquantitative grading scale of allogeneic tracheal grafts (C57BL/6 mice) obtained at day 28 (top, A) from the experimental animal group (allo) [BALB/c mice] receiving allogenic bone marrow from tracheal graft donor animals (n = 6), compared with animals in control group (con) [n = 6] receiving conditioning regimen only (TLI and cyclophosphamide); and at day 95 (bottom, B) from experimental animal group (BALB/c mice) receiving allogeneic bone marrow from tracheal graft donor animals (n = 4), compared with animals in control group (n = 4) receiving conditioning regimen only (TLI and cyclophosphamide) and another group (n = 4) receiving allogeneic tracheal grafts from C57BL/6 mice and syngeneic bone marrow from BALB/c mice (syng). Pathologic processes assessed by the grading scale included airway lumen obliteration (lum) and airway epithelial loss (epi). Median values are presented as horizontal lines. N.S. = not significant.

 
Lymphocytic infiltrates were seen within all layers of the airway wall of the tracheal grafts in control animals not receiving donor BMCs. These infiltrates were accompanied by vascular and perivascular inflammatory changes with occlusion and hyalinization of blood vessels within the allograft. However, allografts from the donor BMC recipients showed minimal or no lymphocytic infiltrates, and blood vessels were remarkably preserved.

Figure 2 shows tracheal allografts at day 55, with patent tracheal lumen in the experimental group compared with the control group. In contrast to total destruction of the airway epithelium in control animals and the thin remnant of basement membrane, there was a marked recovery of ciliated cells with occasional reappearance of intraluminal mucous in BMC recipients.



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  		Figure 2. Cross-section specimens from tracheal grafts obtained at 55 days after transplantation. Specimens obtained from animals receiving donor BMCs showing granulation tissue and fibrosis in airway grafts obtained from control animals (top left, A), while grafts from the experimental animals receiving donor BMCs demonstrated a patent graft lumen (top right, B). There was complete destruction of the lining epithelium in the control animals (bottom left, C) with a thin remnant of basement membrane (arrow), but grafts from the experimental group showed preservation of the airway epithelium (bottom right, D). Top left, A, and top right, B: hematoxylin-eosin, original x 100. Bottom left, C: hematoxylin-eosin, original x 200. Bottom right, D: hematoxylin-eosin, original x 400.

 
Scores of lumen and epithelial morphology evaluation at day 95 are shown in Figure 1, bottom, B. The airway lumen and the lining epithelial cells were preserved in the donor BMC recipients (n = 4) compared with the animals not receiving any BMCs (n = 4). Tracheal grafts from BALB/c animals receiving syngeneic BMCs from BALB/c mice harvested at day 95 (n = 4) also showed complete rejection of the allogeneic tracheal grafts with total destruction of the airway lining epithelium and severe airway lumen fibrosis. Consequently, scores of morphology evaluation of the lumen and the epithelial lining changes did not differ from the control group not receiving donor BMCs (Fig 1, bottom, B).

Chimerism
Chimerism was confirmed in animals receiving allogeneic BMCs by performing FACS analysis on splenocytes representing peripheral blood cells from host animals killed at day 28 and day 55. H-2Db-positive cells formed approximately 2 to 10% of all lymphocytes within the host spleen.

GVHD and Toxicity
Animals from all groups showed a transient decrease of weight 2 to 4 weeks after transplant, which was not accompanied by diarrhea or decreased food intake. At 45 to 55 days after transplant, animals receiving allogeneic BMCs showed some skin changes consisting of mild thinning of the fur with no alopecia or ulcerations, and skin biopsy samples obtained from these animals at day 73 showed minimal changes of mild spongiosis (intradermal edema) and few apoptotic cells, findings consistent with mild graft-vs-host reaction.16 Histopathologic examination of the small intestine, liver, and lungs did not reveal findings suggestive of GVHD.


   Discussion
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
As hypothesized, allograft rejection and obliteration of airway lumen can be prevented in animals in which mixed chimerism was formed by BMCs obtained from the tracheal allograft donor administered after reduced intensity conditioning. Conditioning with TLI and cyclophosphamide only did not prevent obliteration of the tracheal graft lumen by granulation and fibrotic tissue. Additionally, syngeneic BMCs did not facilitate acceptance of allogeneic tracheal grafts; thus, allograft acceptance was dependent on the co-administration of donor BMCs and did not merely result from conditions of bone marrow ablation and reconstitution. Patent airway lumen in the experimental animals was accompanied by recovery of the lining epithelium structure and function, with secretion of mucous into the airway lumen. Notably, donor source BMCs were administered concurrently with tracheal allograft implantation, making this approach appealing for clinical lung transplantation from cadaver donors. The present protocol was accompanied neither by significant toxicity, nor by the development of GVHD except for mild skin changes.

Chronic rejection is still a major obstacle for successful lung transplantation. Lymphoid cells obtained from BAL fluid and the peripheral blood in lung transplant patients with BO compared to those without BO show selective clonal expansion of T-cells.17 Induction of tolerance via mixed chimerism formation presumably leads to clonal deletion of alloreactive cell lines and further prevents formation of such cells. Such a mechanism will be the subject of future research.

In clinical practice, simultaneous administration of donor BMCs, without prior conditioning of the host, achieved detectable chimerism in 73% of heart and lung transplant recipients,18 accompanied by in vitro evidence of donor-specific hyporeactivity in serial mixed lymphocyte reaction analysis. However, there was no significant effect on the incidence of BO.19

Experimental induction of mixed chimerism prevented formation of airway fibroproliferative lesions in both a whole-lung transplant model10 and a tracheal graft model in rats.11 The conditioning protocol in the latter study was based on total myeloablation of the host bone marrow followed by bone marrow reconstitution with a mixture of donor and host T-cell depleted BMCs. There was no evidence of GVHD in both these studies.1011 In the present study, we have modified a reduced intensity BMT protocol that is based on conditioning with TLI and cyclophosphamide.9 Donor BMCs then induced unresponsiveness to donor alloantigens and allowed acceptance of skin and neonatal heart allografts transplanted only 1 month later, without maintenance immunosuppressive drugs.

Antibodies administered to lung transplant patients and targeted against T-cell lymphocyte surface markers (anti-OKT3 and anti-thymocyte globulins) deplete alloreactive T-lymphocytes and control acute rejection, but their effect on the progression of chronic rejection has been dismal.3 Based on previously known immunomodulating properties of cyclophosphamide, it is very likely that cyclophosphamide contributed to the successful induction of mixed chimerism, largely by suppression and elimination of host lymphocytes that could have reacted against the donor tracheal tissue and hematopoietic cells.20 In addition, cyclophosphamide can contribute to the simultaneous elimination of lymphocytes from the transplanted BMCs that are able to react against recipient antigens, thus decreasing the severity of GVHD in the bone marrow recipients.

TLI has probably also caused removal of proliferating alloreactive host cells in this protocol. However, TLI has a unique mechanism of "active" immune tolerance with surveillance against alloreactive cells that presumably causes activation of host immune "suppressor" cells, facilitating engraftment of donor cells and inducing tolerance to donor antigens.21

Several factors should be considered when drawing conclusions from this study. This experimental model differs from whole-lung transplantation in the lack of perfusion of the graft with blood containing circulating lymphocytes and the absence of contact with the external environment and exposure to infectious agents. However, lymphocytic infiltration followed by subepithelial and endoluminal fibrosis is similar to rejection of organs with a luminal structure, and in particular the fibroproliferative lesions within small airways in posttransplant BO.

GVHD was evident in a mild cutaneous form in 20 to 25% of animals with no involvement of visceral organs. Mice are convenient in the study of both graft-vs-host reactions and GVHD because of the availability of congenic strains within well-defined histocompatibility antigens, and the ability to detect clinically less obvious graft-vs-host reactions within these murine models. However, since GVHD is less predictable in man, findings in murine experimental systems do not always correlate with human clinical experience.

In conclusion, we have shown that the formation of the airway fibroproliferative lesion associated with tracheal graft rejection can be prevented by simultaneous administration of donor BMCs following reduced intensity conditioning. Further research is needed to evaluate the role of this approach in the prevention of BO in human lung transplantation.


   Footnotes
 
Abbreviations: BMC = bone marrow cell; BMT = bone marrow transplantation; BO = bronchiolitis obliterans; FACS = fluorescence-activated cell sorting; GVHD = graft vs host disease; TLI = total lymphoid irradiation

This work is supported by grants from the Chief Scientist’s Office of the Israel Ministry of Health, The Yael Research Fund, The Joint Research Fund of the Hebrew University and Hadassah, The Israel Lung Association (Tel-Aviv), and The David Shainberg Fund.

Received for publication May 11, 2005. Accepted for publication August 31, 2005.


   References
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Trulock, EP, Edwards, LB, Taylor, DO, et al (2003) The Registry of the International Society for Heart and Lung Transplantation: Twentieth official adult lung and heart-lung transplant report–2003. J Heart Lung Transplant 22,625-635[CrossRef][ISI][Medline]
  2. Brock, MV, Borja, MC, Ferber, L, et al Induction therapy in lung transplantation: a prospective, controlled clinical trial comparing OKT3, anti-thymocyte globulin, and daclizumab. J Heart Lung Transplant 2001;20,1282-1290[CrossRef][ISI][Medline]
  3. Date, H, Lynch, JP, Sundaresan, S, et al The impact of cytolytic therapy on bronchiolitis obliterans syndrome. J Heart Lung Transplant 1998;17,869-875[ISI][Medline]
  4. Valentine, VG, Robbins, RC, Wehner, JH, et al Total lymphoid irradiation for refractory acute rejection in heart-lung and lung allografts. Chest 1996;109,1184-1189[Medline]
  5. Starzl, TE, Demetris, A, Trucco, M, et al Chimerism and donor specific nonreactivity 27 to 29 years after kidney allotransplantation. Transplantation 1993;55,1272-1277[ISI][Medline]
  6. Starzl, TE, Demetris, AJ, Trucco, M, et al Cell migration and chimerism after whole-organ transplantation: the basis of graft acceptance. Hepatology 1993;17,1127-1152[CrossRef][ISI][Medline]
  7. Ueda, M, Hundrieser, J, Hisanaga, M, et al Development of microchimerism in pediatric patients after living-related liver transplantation. Clin Transplant 1997;11,193-200[Medline]
  8. Hisanaga, M, Hundrieser, J, Boker, K Development, stability, and clinical correlations of allogeneic microchimerism after solid organ transplantation. Transplantation 1996;61,40-45[CrossRef][Medline]
  9. Prighozina, TB, Gurevitch, O, Slavin, S Nonmyeloablative conditioning to induce bilateral tolerance after allogeneic bone marrow transplantation in mice. Exp Hematol 1999;27,1503-1510[CrossRef][Medline]
  10. Pham, SM, Mitruka, SN, Youm, W, et al Mixed hematopoietic chimerism induces donor-specific tolerance for lung allografts in rodents. Am J Respir Crit Care Med 1999;159,199-205[Abstract/Free Full Text]
  11. Gammie, JS, Li, S, Kawaharada, N, et al Mixed allogeneic chimerism prevents obstructive airway disease in a rat heterotopic tracheal transplant model. J Heart Lung Transplant 1998;17,801-808[Medline]
  12. Hertz, MI, Jessurun, J, King, MB, et al Reproduction of the obliterative bronchiolitis lesion after heterotopic transplantation of mouse airways. Am J Pathol 1993;142,1945-1951[Abstract]
  13. Boehler, A, Chamberlain, D, Kesten, S, et al Lymphocytic airway infiltration as a precursor to fibrous obliteration in a rat model of bronchiolitis obliterans. Transplantation 1997;64,311-317[CrossRef][ISI][Medline]
  14. Slavin, S, Strober, S, Fuks, Z, et al Induction of specific tissue transplantation tolerance using fractionated total lymphoid irradiation in adult mice: long-term survival of allogeneic bone marrow and skin grafts. J Exp Med 1977;146,34-38[Abstract/Free Full Text]
  15. Snedecor, GW, Cochran, GW Statistical methods. 6th ed. 1967,258-298 Iowa State University Press. Ames, IA:
  16. Rappaport, H, Khalil, A, Halle-Pannenko, O, et al Histopathologic sequence of events in adult mice undergoing lethal graft-versus-host reaction developed across H-2 and/or non-H-2 histocompatibility barriers. Am J Pathol 1979;96,121-142[Abstract]
  17. Duncan, SR, Valentine, V, Roglic, M, et al T cell receptor biases and clonal proliferations among lung transplant recipients with obliterative bronchiolitis. J Clin Invest 1996;97,2642-2650[ISI][Medline]
  18. Pham, SM, Keenan, RJ, Rao, AS, et al Perioperative donor bone marrow infusion augments chimerism in heart and lung transplant recipients. Ann Thorac Surg 1995;60,1015-1020[Abstract/Free Full Text]
  19. Pham, SM, Rao, AS, Zeevi, A, et al Effects of donor bone marrow infusion in clinical lung transplantation. Ann Thorac Surg 2000;69,345-350[Abstract/Free Full Text]
  20. Hengst, JC, Kempf, RA Immunomodulation by cyclophosphamide. Clin Immunol Allergy 1984;4,199-216
  21. Slavin, S, Strober, S Induction of allograft tolerance after total lymphoid irradiation (TLI): development of suppressor cells of the mixed leukocyte reaction (MLR). J Immunol 1979;123,942-946[Abstract/Free Full Text]




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