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(Circulation. 1995;92:987-993.)
© 1995 American Heart Association, Inc.
Articles |
From Brigham and Women's Hospital and Harvard Medical School, Boston, Mass.
Correspondence to Dr Peter Libby, Vascular Medicine and Atherosclerosis Unit, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Longwood Medical Research Center, Room 307, 221 Longwood Ave, Boston, MA 02115.
| Abstract |
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Methods and Results A control group (n=5) received cyclosporine 5 mg · kg-1 · d-1 for 6 weeks after heterotopic heart transplantation. In a rejection group (n=5), cyclosporine was omitted for 4 days at 1 and 4 weeks after transplantation. We studied cross sections of grafted hearts at 6 weeks and evaluated myocardial rejection grade, incidence, and severity and cell composition of intimal lesions in multiple coronary artery profiles. Episodic withdrawal of cyclosporine augmented myocardial rejection (International Society for Heart and Lung Transplantation grades 0, 0, 0, 0, and 1A in the control group to grades 1A, 1B, 2, 3A, and 3B in the rejection group). Episodes of acute rejection significantly increased the incidence (7.8±2.7% to 49.7±1.9%) and severity (from grade 0.10±0.04 to 0.79±0.24) of intimal thickening in graft coronary arteries. Most intimal lesions consisted of smooth muscle cells and contained various degrees of T-lymphocyte infiltration but sparse macrophages.
Conclusions In this experimental model, episodes of acute rejection precipitated by cyclosporine withdrawal accelerated the development of graft vascular lesion formation. Activation of vascular cells and leukocyte recruitment during acute rejection may thus contribute to the pathogenesis of graft arteriosclerosis.
Key Words: rejection arteritis cyclosporine transplantation arteriosclerosis
| Introduction |
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-interferon that can in turn augment EC
expression of histocompatibility antigens and stimulate
macrophages. Activated T cells also elaborate tumor necrosis
factor-
and lymphotoxin, which can alter many functions of vascular
cells, including the production of further cytokines. This
cascade of mediators released as a consequence of T-cell activation may
then alter growth, migration, and extracellular matrix
metabolism by vascular smooth muscle cells (SMCs),
promoting the development of the fibroproliferative intimal lesions
characteristic of graft coronary
arteriosclerosis.2 Although the pathological hallmarks of acute parenchymal rejection (cytolytic injury) and chronic rejection or graft coronary arteriosclerosis (a fibroproliferative response) differ, they share the common elements of T-cell activation and cytokine elaboration. Indeed, our previous studies presented evidence supporting activation of both ECs and SMCs in rabbit cardiac allograft coronary arteries during acute rejection.3 In this manner, activation of the arterial wall cells during episodes of acute rejection might trigger or exacerbate the development of graft coronary arteriosclerosis. In support of this concept, some clinical reports suggest a relation between episodes of acute rejection and the development of graft coronary arteriosclerosis.4 5 6 7 8 However, the complexities of the clinical situation, such as the different immunosuppressive regimens used to prevent and treat acute rejection, the possible influence of intercurrent opportunistic infections, and the limitations of accurate diagnosis of graft coronary arteriosclerosis intra vitam, render it difficult to isolate acute rejection as a variable in clinical studies.
For these reasons, we examined the hypothesis that acute rejection episodes accelerate graft coronary arteriosclerosis lesion formation in a well-defined animal model. We used rabbits with heterotopic cardiac allografts, inducing bouts of acute myocardial rejection by episodic withdrawal of immunosuppression. This rabbit preparation afforded ready access to tissue for analysis under carefully controlled conditions and permitted us to characterize certain cellular aspects of vascular lesion formation and monitor the presence of graft coronary arteriosclerosis.
| Methods |
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The recipient New Zealand White rabbits were anesthetized in the same fashion, and the right common carotid artery and external jugular vein were dissected. After injection of heparin sodium (500 U IV), the ascending aorta and the main pulmonary artery of the donor heart were anastomosed to the carotid artery and jugular vein of the recipient, respectively, by use of a modified Carrel's technique.
During the procedure, we kept the donor heart cool by superfusion with ice-cold lactated Ringer's solution. After reperfusion and stabilization of its rhythm, the grafted heart was placed in a subcutaneous pocket constructed in the recipient's neck. Total ischemic time ranged from 35 to 45 minutes. Postoperatively, graft heart function was monitored by assessment of the size and the frequency and force of contraction by daily palpation. All experiments were performed in accordance with the "Guide for the Care and Use of Laboratory Animals" (NIH publication No. 80-23, revised in 1978).
Immunosuppression and the Experimental Group
In a control
group (n=5), recipient rabbits received
cyclosporine (5
mg · kg-1 · d-1 sc) starting
immediately after the surgery and continuing until death. In the
rejection group (n=5), cyclosporine was omitted for 4 days
at 1 and 4 weeks after transplantation. These times were determined in
pilot experiments to yield substantial rejection (see below), yet to a
degree that did not threaten graft survival. To document the extent of
myocardial rejection after cyclosporine was withheld for 4
days, four additional rabbits were killed at the end of the first
interruption of cyclosporine (the acute phase group).
Sample Preparation
At 6 weeks after transplantation, we
killed recipients by
infusion of pentobarbital (30 mg/kg IV) after systemic heparinization
(2000 U IV), excised the graft heart, and flushed the coronary
circulation with saline through the aortic root. We prepared two 2- to
3-mm-thick cross sections of the heart near the cardiac base. One
whole-mounted specimen was frozen in optimum-cutting-temperature
compound (OCT, Miles) to permit cryosectioning and optimal
analysis of cell type and activation markers by
immunohistochemical techniques. The other slice was fixed in 4%
buffered paraformaldehyde and then embedded in paraffin
for preparation of standard histological specimens,
which are optimal for examination of morphology.
Morphological Evaluation
Paraffin sections (5 µm thick)
were stained with hematoxylin
and eosin for general morphology and for the grading of myocardial
rejection according to the International Society for Heart and Lung
Transplantation (ISHLT) criteria,9 with minor
modification, as this scheme was originally formulated for the
evaluation of endomyocardial biopsies. Serial paraffin sections were
also stained with van Gieson's stain for elastin to evaluate the
coronary arterial intimal lesions and with
Masson's trichrome stain to evaluate fibrosis. The whole-mounted cross
sections allowed systematic analysis of multiple
coronary artery profiles per section to permit
representative sampling. We evaluated all arteries in
each section but excluded from analysis a priori certain
epicardial coronary arteries with superficial locations that
rendered them susceptible to physical trauma during surgery. We also
excluded occasional arteries surrounded by myocardial scars, which
probably represent areas of perioperative
ischemic injury. These exclusions permitted analysis of
34±2 coronary artery profiles in each section examined.
Morphological analysis first assessed the presence or absence of intimal lesions in a binary fashion to determine the incidence of intimal lesions in each heart. We did not consider a quantitative morphometric approach to the assessment of intimal lesions appropriate because many arteries were sectioned tangentially and the hearts were not perfusion-fixed at physiological pressure, a procedure that would not optimally preserve antigens for immunocytochemical analysis. For this purpose, we adopted a semiquantitative grading scale similar to previously described scoring systems.6 An independent observer graded the intimal lesions as follows: 0, no intimal lesion; 1, up to 25% luminal stenosis by intimal lesion; 2, >25% to 50%; 3, >50% to 75%; and 4, >75% luminal stenosis. Every coronary artery in the whole-mounted cross section from each heart was thus scored, and an average grade was determined for each heart. We also evaluated the disruption of the internal elastic lamina (IEL) in a binary fashion as absent (intact or <10% disruption of the IEL) or present (>10% disruption). Graft vascular disease characteristically involves small and large coronary arteries. To examine the distribution of lesions in these hearts, we also analyzed the results according to artery size. We divided them into two classes: (1) major coronary arteries and their large branches and (2) small branches, including arterioles.
Immunocytochemistry
Immunocytochemical staining to examine
the cellular composition
of the lesions used the following antibodies. Monoclonal antibody (mAb)
HHF-35 (mouse IgG1, purchased from Enzo Diagnostic)
recognizes rabbit musclespecific actin; mAb L-11/135 (mouse IgG1,
American Type Culture Collection) detects a 120-kD
glycoprotein determinant present on rabbit thymocytes
and peripheral T lymphocytes; and mAb RAM-11 (mouse IgG1,
provided by Dr A. Gown as ascites fluid) recognizes an uncharacterized
cytoplasmic antigen protein expressed by rabbit macrophages.
ECs were identified by expression of von Willebrand factor
(vWF), a constitutive EC maker, using a polyclonal goat anti-human
antibody (Atlantic Antibodies) that cross-reacts with rabbit vWF.
Staining was performed on both frozen and paraffin sections. Cryostat sections (6 µm thick) were cut, air-dried onto poly-L-lysinecoated slides, and fixed in acetone at -20°C for 5 minutes. Paraffin sections were deparaffinized with xylene and rehydrated by passage through successively diluted ethanol solutions, finishing with water. Endogenous peroxidase was suppressed by treatment with 0.3% hydrogen peroxide in Dulbecco's PBS for 20 minutes. Nonspecific background staining was limited by preincubating with 10% normal horse serum in PBS for 20 minutes. Then the primary antibodies diluted in PBS with 10% horse serum were applied and incubated for 60 minutes at ambient temperature. After washing, species-appropriate biotinylated secondary antibodies were applied, followed by avidin-biotin peroxidase complex (Vectasin ABC kit, Vector Laboratories). Antibody binding was visualized with 3-amino-9-ethylcarbazole (Sigma Chemical Co); then sections were counterstained with Gill's hematoxylin (Sigma Diagnostics).
Data Analysis
ANOVA (STATVIEW) was used to evaluate
the effect
of acute rejection or vessel size on the incidence and severity of
intimal thickening. A value of P<.05 was considered
statistically significant. Data are given as mean±SEM.
| Results |
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Interruption of Cyclosporine Therapy for 4 Days
Provokes Development of Variable Degrees of Myocardial
Rejection
We assessed myocardial histology after the initial 4-day
period of
cyclosporine withdrawal by examining hearts from 4
recipients killed at that point in the experimental protocol (acute
phase group). The degree of myocardial rejection varied widely in these
hearts (grades 1A, 1A, 3B, and 4). Because of this variability, we
monitored the blood concentration of cyclosporine in the
second pair of animals studied according to this protocol. Although we
administered the same dose of cyclosporine (5
mg · kg-1 · d-1) to both
animals, the
blood cyclosporine level in the animal with grade 1A
rejection was higher during the 4-day interruption than in the animal
with grade 3B rejection (Table 1
).
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Episodic Withdrawal of Cyclosporine Augments Myocardial
Rejection at 6 Weeks After Transplantation
In the control group,
examination of the grafted hearts 6 weeks
after transplantation showed that the continuous administration of
cyclosporine almost completely suppressed myocardial
rejection (no rejection in 4 of 5 hearts; the remaining heart had an
ISHLT rejection grade of 1A, Table 2
). In the animals
subjected to two 4-day periods of cyclosporine withdrawal
(the rejection group), the degree of myocardial rejection in the
grafted hearts 6 weeks after transplantation was higher than in the
control animals in 4 of 5 cases and varied from grade 1A to 3B (Table
2
).
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Episodes of Acute Myocardial Rejection Produced by
Cyclosporine Withdrawal Increased the Incidence and
Severity of Intimal Thickening in Graft Coronary Arteries
The
incidence of intimal thickening was determined in a binary
fashion, as explained above. The rejection group had a significantly
higher incidence of intimal lesions (
50% of the graft
coronary arteries had some degree of intimal thickening) than
did the control group (<10% of these arteries, Table 2
).
The majority of the arteries of the hearts in the control group showed
no intimal lesions (grade 0, Fig 1A
). Only 1 heart
(animal 5) that had grade 1A myocardial rejection showed relatively
advanced coronary artery lesions. The overall average lesion
grade of the control group was 0.10±0.04. In contrast, most of the
hearts in the rejection group had more advanced lesions and fewer
normal arteries. The average grade for the severity of intimal
thickening in the rejection group significantly exceeded that of the
control group by nearly eightfold (0.79±0.24, Table 2
).
|
Analysis of frozen sections revealed that most of these
arterial intimal lesions consisted of SMCs (Fig 2B
), but some
also contained T lymphocytes (Fig 2C
).
Macrophages were sparse in these lesions (Fig 2D
). Observations
on paraformaldehyde-fixed paraffin-embedded sections
were consistent with the findings on frozen sections. Some
intimal lesions contained mostly SMCs and had very few T lymphocytes
(Fig 3A
through 3D), but sometimes T cells were more
abundant (Fig 3E
through 3H) or accumulated in the
subendothelial portion of the intima (Fig 3I
through
3L) or in regional foci corresponding to the perivascular infiltration
(Fig 3M
through 3P). These histological features and
the heterogeneity of lesions resemble the findings in
human graft coronary disease.
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Lesions of Graft Vascular Disease Affected Both Large and Small
Coronary Arteries
Although large arteries tended to develop more
intimal
lesions of greater severity than small arteries, there was no
statistically significant difference in this regard, despite the large
number of individual arteries analyzed (Table 3
). This result
indicates that in this model, graft
vascular disease affects both epicardial and intramural
coronary arteries, as in the clinical situation.
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Vasculitis in Coronary Arteries of Hearts Subjected to
Episodes of Acute Rejection
Perivascular and interstitial leukocyte
infiltration, myocyte damage, and vascular injury are the cardinal
features of the histology of acute allograft rejection. Experimental
and clinical observations have documented other features of acute
vasculitis and vascular cell activation during acute rejection of
cardiac allografts. Indeed, we found intimal accumulation of leukocytes
and perivascular lymphocyte infiltration in some hearts undergoing
acute rejection in the animals from which cyclosporine had
been omitted for only 4 days (the acute phase group, Fig 1B
).
All
4 hearts in the acute phase group had a few arterial
intimal lesions.
It is possible that such perivasculitis or arteritis promotes the development of the more chronic fibroproliferative changes characteristic of graft vascular disease. One manifestation of healed vasculitis is disruption of the IEL, a finding we noted in many arteries with graft vascular disease in this study.
To examine the
possible relation between previous acute arteritis and
subsequent development of graft vascular disease, we assessed the
degree of IEL disruption according to the grade of intimal thickening
of each artery. This analysis revealed a clear correlation
between the disruption of IEL and the extent of intimal thickening (Fig
4
).
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Chronic Vascular Disease in Allografted Hearts Also Affects
Coronary Veins
In human cardiac allografts, veins can manifest signs
of graft
vascular disease as well as arteries, a finding compatible with our
pathogenic schema for this process. We therefore sought intimal
thickening in coronary veins in this model. Although some veins
were oval and resembled arteries, they have several features that
distinguish them from arteries: (1) a very thin or almost absent medial
smooth muscle layer, (2) a thicker adventitia or surrounding connective
tissue, and (3) a relatively indistinct IEL (Fig 5
).
Veins identified by these criteria had advanced concentric intimal
thickening in 2 of 5 hearts in the rejection group but in none of the
control group hearts. The histology of these venous lesions resembled
that of graft arterial disease in some respects, but these
lesions were less cellular than the arterial lesions. The
cellular population consisted primarily of SMCs with rare T lymphocytes
(Fig 5G
and 5H
). Collagen did not appear to be
the dominant
constituent of the abundant extracellular matrix of the
lesions, as indicated by scant reaction with Masson's trichrome
stain (Fig 5I
).
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| Discussion |
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Although many clinical reports suggested that acute rejection predicts the development of graft coronary arteriosclerosis, this association remains controversial.12 13 14 15 In view of the many variables that can confound such clinical analyses, we developed here an animal model to test whether episodes of acute rejection accelerate the development of the intimal lesions of graft vascular disease. Previous work16 and pilot trials verified that daily injection of cyclosporine (5 mg · kg-1 · d-1 sc) almost completely suppresses myocardial rejection in this rabbit allograft model. The engrafted hearts of rabbits treated in this manner show slight or no coronary arterial intimal lesion development within 6 weeks.
Deliberate withdrawal of cyclosporine for 5 to 8 days after an initial 1 week "induction" period evoked moderate to severe (grade 3 to 4) acute rejection. Reinstitution of cyclosporine at the maintenance dose "rescued" the hearts and permitted long-term graft survival. On the basis of pilot experiments, we chose a 4-day period of cyclosporine interruption to produce mild to moderate (grade 1 to 3) rejection. We produced two "rejection" episodes in this manner to mimic the clinical course of many patients who undergo several rejection episodes during the first year after transplantation.
As in the clinical situation, we found considerable variation in the
degree of rejection during these acute episodes. Individual rabbits may
differ in cyclosporine pharmacokinetics, as we showed
(Table 1
). The differing degree of MHC mismatch and thus the
intensity
of the allogenic response in each outbred donor-recipient pair also may
contribute to the range in degrees of rejection produced in this model.
This heterogeneity mimics that encountered in clinical
heart transplantation.
Despite the variability in the myocardial rejection grade, 4 of 5 animals in the rejection group developed substantial incidence and severity of coronary arterial intimal thickening. This result supports the link between acute rejection and chronic graft vascular lesion formation. However, the degree of myocardial acute rejection found at the time of postmortem examination did not necessarily predict the arterial lesion formation. An alternative and equally interesting explanation for our data would be that cyclosporine, by blocking T-cell interleukin-2 production, interrupts the cytokine cascade that we believe underlies the development of the intimal fibroproliferative response in transplanted vessels regardless of any effect on acute rejection. In fact, a combination of these two phenomena, difficult to distinguish experimentally, could account for the observed marked enhancement in intimal disease in the rejection group.
In the lesions of human graft coronary arteriosclerosis, the IEL was thought to be preserved until a very late stage.17 18 However, some recent studies suggested that the disruption of IEL is not so rare.19 As in other experimental models, we often observed IEL disruption; this finding correlated well with the grade of intimal thickening. This result suggests a potential mechanism for the potentiation of graft coronary arteriosclerosis by acute rejection. The acute endovasculitis and perivasculitis characteristic of acute parenchymal rejection may promote local leukocyte recruitment and activate vascular cells to express adhesion molecules and elaborate cytokines, chemoattractants, growth factors, and mediators that stimulate accumulation of extracellular matrix materials. Thus, shared cellular mechanisms could explain the accelerated formation of vascular fibroproliferative lesions in the hearts subjected to acute rejection, as in the more indolent development of intimal disease in chronically immunosuppressed animals.
By triggering aspects of the same "final common pathway" of a cytokine-dependent mediator cascade, acute rejection may simply hasten the development of a process that otherwise would occur more slowly in the allografted vessels. This overlap in effector mechanisms could explain why clinical graft vascular disease sometimes develops in hearts that have never experienced overt acute myocardial rejection. On the other hand, the discontinuities in the arterial IEL in our rabbits previously subjected to acute rejection suggests that this finding in certain other patients with graft coronary arteriosclerosis may represent the residue of arteritis produced during previous episodes of acute rejection.
If an allogenic response to histoincompatible endothelium plays a major role in the pathogenesis of the graft arterial lesion, one might expect a similar phenomenon in allografted veins. The obvious differences in shear stress and pressure in veins, in addition to their distinct structure, might modulate the manifestations of the allogenic response in veins. Because venous lesions have less ominous clinical consequences than arterial involvement, venous disease in transplanted organs has received little attention. Some studies of explanted or autopsied heart allografts have indeed suggested intimal proliferative lesions in veins.6 20 The finding of coronary venous lesions in the experiments reported here substantiates the relevance of this model to the clinical situation and supports our view on the role of the vascular allogenic response as a contributor to the pathogenesis of graft vascular disease. As stated above, these experiments do not establish a specific immunopathological mechanism for the accelerated vascular disease in the rejection group. Indeed, multiple factors probably contribute to this process.
The present finding that acute rejection episodes promote graft coronary artery disease does not necessarily imply that more aggressive immunosuppression with conventional drugs should be given to prevent the vascular disease, as suggested by Addonizio et al.8 However, further studies of the mechanism of activation of vascular wall cells and control of the arterial fibroproliferative response may aid the development of more specific approaches to the prevention of graft vascular disease, which currently limits the long-term outlook for recipients of organ allografts.
| Acknowledgments |
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Received November 7, 1994; revision received February 21, 1995; accepted February 28, 1995.
| References |
|---|
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|---|
2. Hosenpud JD, Shipley GD, Wagner CR. Cardiac allograft vasculopathy: current concepts, recent developments, and future directions. J Heart Lung Transplant. 1992;11:9-23. [Medline] [Order article via Infotrieve]
3. Tanaka H, Sukhova GK, Swanson SJ, Cybulsky MI, Schoen FJ, Libby P. Endothelial and smooth muscle cells express leukocyte adhesion molecules heterogeneously during acute rejection of rabbit cardiac allografts. Am J Pathol. 1994;144:938-951. [Abstract]
4.
Uretsky BF, Murali S, Reddy PS, Rabin B, Lee A,
Griffith BP, Hardesty RL, Trento A, Bahnson HT. Development of
coronary artery disease in cardiac transplant patients
receiving immunosuppressive therapy with cyclosporine and
prednisone. Circulation. 1987;76:827-834.
5. Narrod J, Kormos R, Armitage J, Hardesty R, Ladowski J, Griffith B. Acute rejection and coronary artery disease in long-term survivors of heart transplantation. J Heart Lung Transplant. 1989;8:418-421.
6. Liu G, Butany J. Morphology of graft arteriosclerosis in cardiac transplant recipients. Hum Pathol. 1992;23:768-773. [Medline] [Order article via Infotrieve]
7. Zerbe T, Uretsky B, Kormos R, Armitage J, Wolyn T, Griffith B, Hardesty R, Duquesnoy R. Graft atherosclerosis: effects of cellular rejection and human lymphocyte antigen. J Heart Lung Transplant. 1992;11:S104-S110. [Medline] [Order article via Infotrieve]
8. Addonizio LJ, Hsu DT, Douglas JF, Kichuk MR, Michler RE, Quaegebeur JM, Smith CR, Rose EA. Decreasing incidence of coronary disease in pediatric cardiac transplant recipients using increased immunosuppression. Circulation. 1993;88(part 2):224-229.
9. Billingham ME, Cary NRB, Hammond ME, Kemnitz J, Marboe C, MacCallister HA, Snovar DC, Winters GL, Zerbe A. A working formulation for the standardization of nomenclature in the diagnosis of heart and lung rejection: heart rejection study group. J Heart Lung Transplant. 1990;9:587-593.
10. Libby P, Salomon RN, Payne DD, Schoen FJ, Pober JS. Functions of vascular wall cells related to development of transplantation-associated coronary arteriosclerosis. Transplant Proc. 1989;21:3677-3684. [Medline] [Order article via Infotrieve]
11. Briscoe DM, Schoen FJ, Rice GE, Bevilaqua MP, Ganz P, Pober JS. Induced expression of endothelial-leukocyte adhesion molecules in human cardiac allografts. Transplantation. 1991;51:537-539. [Medline] [Order article via Infotrieve]
12. Russell ME, Fujita M, Masek MA, Billingham ME. Cardiac graft vascular disease. Transplantation. 1993;56:762-763.
13. Gao S, Schroeder JS, Hunt SA, Valantine HA, Hill IR, Stinson EB. Influence of graft rejection on incidence of accelerated graft coronary artery disease: a new approach to analysis. J Heart Lung Transplant. 1993;12:1029-1035. [Medline] [Order article via Infotrieve]
14. Stovin PGI, Sharples LD, Schofield PM, Cary NRB, Mullins PA, English TAH, Wallwork J, Large SR. Lack of association between endomyocardial evidence of rejection in the first six months and the later development of transplant-related coronary artery disease. J Heart Lung Transplant. 1993;12:110-116. [Medline] [Order article via Infotrieve]
15. Costanzo-Nordin MR. Cardiac allograft vasculopathy: relationship with acute cellular rejection and histocompatibility. J Heart Lung Transplant. 1992;11:S90-S103. [Medline] [Order article via Infotrieve]
16.
Tanaka H, Sukhova GK, Libby P. Interaction of
the allogeneic state and hypercholesterolemia in
arterial lesion formation in experimental cardiac
allografts. Arterioscler Thromb. 1994;14:734-745.
17. Hruban RH, Beschorner WE, Baumgartner WA, Augustine SM, Ren H, Reitz BA, Hutchins GM. Accelerated arteriosclerosis in heart transplant recipients is associated with a T-lymphocyte-mediated endothelialitis. Am J Pathol. 1990;137:871-882. [Abstract]
18. Schoen FJ, Libby P. Cardiac transplant graft arteriosclerosis. Trends Cardiovasc Med. 1991;1:216-223.
19. Paavonen T, Mennander A, Lautenschlager I, Mattila S, Häyry P. Endothelialitis and accelerated arteriosclerosis in human heart transplant coronaries. J Heart Lung Transplant. 1993;12:117-122. [Medline] [Order article via Infotrieve]
20. Oni AA, Ray J, Hosenpud JD. Coronary venous intimal thickening in explanted cardiac allografts. Transplantation. 1992;53:1247-1251. [Medline] [Order article via Infotrieve]
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