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Effects of cyclosporin, FK506, and rapamycin on graft-vessel disease
1297
breathing during sleep
causes
J Appl Physiol 1986; 61:
upper 1438-43.
airway obstruction
in
humans.
4. Henke HG, Arias A, Skatrud JB, Dempsey JA. Inhibition of inspiratory muscle activity during sleep: chemical and nonchemical influences. Am Rev Respir Dis 1988; 138: 8-15. 5. Rodenstein DO, Stanescu DC, Delguste P, Liistro G, Aubert-Tulkens G. Adaptation to intermittent positive pressure ventilation applied through the nose during day and night. Eur Respir J 1989; 2: 473-78. 6. Heckmatt JZ, Loh L, Dubowitz V. Night-time ventilation in neuromuscular disease. Lancet 1990; 335: 579-82. 7. Meduri GU, Conoscenti CC, Menashe P, Nair S. Noninvasive face mask ventilation in patients with acute respiratory failure. Chest 1989; 95:
865-70.
Rehabilitation PhD), (P. Delguste, Electrophysiology (G. Aubert-Tulkens, MD), and Pneumology (D. O. Rodenstein, MD) Units, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium. Correspondence to Dr D O Rodenstein, Service de Pneumologie, Cliniques Universitaires Saint-Luc, Avenue Hippocrate 10, B-1200 Brussels, Belgium
ADDRESSES:
Effects of cyclosporin, FK506, and rapamycin on graft-vessel disease
Graft-vessel disease (GVD) limits the long-term survival of heart-transplant patients, and this effect has not been altered by use of cyclosporin for immunosuppression. We compared the effects of the immunosuppressants cyclosporin, FK506, and rapamycin on GVD in a rat-heart transplantation model. Allografted hearts from rats treated with 1 mg/kg FK506 for 50 days showed the same degree of myocardial rejection but a significantly worse (p<0·05) grade of GVD compared with grafted hearts from rats treated with 1·5 mg/kg cyclosporin for the same time. 2 mg/kg FK506 for 50 days
prevented cellular rejection but GVD was as severe as that found with 1 mg/kg FK506. Moderate GVD was present in two of five allografted hearts after treatment with 4 mg/kg FK506. 1·5 mg/kg rapamycin for 50 days was an effective inhibitor of rejection and GVD. Based on our results in rats, the possibility that GVD may occur in human hearttransplant recipients treated with FK506 cannot be excluded.
Despite immunosuppression with cyclosporin, graftvessel disease (GVD) remains the principal complication limiting the long-term survival of heart-transplant patients. The cause and pathogenesis of GVD are not well understood. Early angiographic detection of GVD is difficult’ because, unlike atherosclerosis in native coronary arteries, GVD is diffuse and occurs in small vessels before large coronary arteries. The need for improved suppressants of graft rejection led to identification of the structurally related macrolides-FK506 and rapamycin. Although many immunosuppressive activities of cyclosporin, FK506, and rapamycin have been described, the relative potencies and efficacies of these drugs for control of GVD have not been compared. Because cyclosporin increases serum cholesterol concentrations2 and because FK506 and rapamycin cause vasculitis in dogs,3,4 these drugs may potentially exacerbate GVD. We used a rat-heart transplantation model, in which lesions are produced that resemble GVD in man,’ to compare the effects of cyclosporin, FK506, and rapamycin on GVD. Hearts from Brown Norway or Lewis rats were transplanted into the abdomens of Lewis rat recipients’ and groups of five animals were treated daily with immunosuppressants or saline as shown in the table.* The extent of myocardial cellular rejection was graded on a scale from 0 to 3 on the basis of the extent of lymphocyte infiltration and myocyte necrosis. GVD was graded on a scale from 0 to 4 according to the severity of vessel injury. Differences between groups in grades of cellular rejection and of GVD were analysed by the Mann-Whitney U test (1-tailed).
cellular rejection and only slight GVD in hearts from rats treated with saline. Allografted isografted hearts from rats treated with 1 -5 mg/kg cyclosporin showed There
was no
lymphocyte infiltration and GVD was not significantly worse than in grafts from the saline-treated group (p > 0’05) (table). Treatment with 6 mg/kg cyclosporin abolished cellular rejection and GVD. Rapamycin (1-5 mg/kg) prevented cellular graft rejection and GVD (figure) as effectively as did 6 mg/kg of cyclosporin (p > 0-05). Allografted hearts from rats treated with 1 mg/kg FK506 showed the same degree of myocardial rejection (p > 0-05) but significantly worse GVD (p <0’05) compared with grafts from rats treated with 1-5 mg/kg cyclosporin. Although 2 mg/kg FK506 completely prevented cellular rejection, GVD was as severe (figure) as in grafts from rats treated with 1 mg/kg FK506 (p > 0-05). sparse
mg/kg
FK506 abolished GVD in three of the five transplanted hearts and two hearts showed moderate GVD 4
(both grade 2-0). Isograft recipients treated with 2 mg/kg FK506 for the first 50 days after transplantation had GVD that was as *Details of the administration of drugs, preparation of sections of heart tissue, and the blinded histological grading are available from The Lancet.
SCHEDULE AND OUTCOME OF TREATMENT WITH IMMUNOSUPPRESANTS IN RATS AFTER CARDIAC TRANSPLANTATION
1298
Photomicrographs of rat heart allograft tissue after 50 days of treatment with rapamycin or FK506.
Top: 15 mg/kg per day rapamycin, GVD = grade 0 (magnification x 250). Bottom 2 0 mg/kg per day FK506; GVD -grade 3 and there is interruption of the lamina and severe intimal proliferation (magnification x 350) extensive as that found in allografted hearts from rats treated with the same dose of drug (p > 0-05). When treatment with 2 mg/kg FK506 was delayed until day 51, and continued for 50 days thereafter, GVD was reduced in three of five transplanted hearts, two hearts still showed moderate GVD (grades 1 ’5 and 2-0). The effect of FK506 on recipients’ own hearts was assessed. Despite varying degrees of GVD in the different treatment groups, all native hearts were histologically normal. This study showed that neither cyclosporin nor rapamycin exacerbated GVD. Rapamycin is known to prolong allograft survival in rodents more potently and effectively than cyclosporin or FK506,7 and the present study showed that rapamycin was the most potent inhibitor of GVD. Cyclosporin inhibits smooth-muscle-cell proliferation induced by immune cells after mechanical injury to the endothelium,s and rapamycin might have similar effects. FK506 causes coronary arteritis in canine renal allograft recipients,3but in our study it did not cause vascular disease in native rat hearts. In allografted hearts, however, treatment with 1 mg/kg FK506 was associated with a GVD score nearly three times greater than that found with treatment with 1-5 mg/kg cyclosporin. 2 mg/kg FK506 completely inhibited cellular rejection, but GVD remained severe. The highest dose of FK506 abolished GVD in some, but not all, hearts. Minimal GVD developed in coronary vessels from saline-treated isografted hearts. In the absence of rejection, GVD in isografts is probably initiated by non-immune mechanisms. Endothelial cell damage (due, for example, to preservation, ischaemia, and reperfusion) seems to be the initial event that ultimately leads to GVD. Since FK506 exacerbated GVD in isografted hearts only when it was given immediately after surgery, and none of the native
hearts from recipients treated with FK506 exhibited any GVD, endothelial cell damage may be a prerequisite for induction of GVD by FK506. After 50 days, when the endothelium had recovered from initial damage, the ability of FK506 to induce GVD was significantly reduced. Additional immunological mechanisms may have a role in the development of GVD in allografts. It seems that cytokines and growth factors (eg, interleukin-1, tumour necrosis factor, and platelet-derived growth factor) produced by activated vessel-wall cells and infiltrating cells are important in the pathogenesis of GVD. Interferon inhibits smooth-muscle-cell however, gamma, proliferation.9 FK506 inhibits selectively the expression in vitro of mRNAs for the genes of early T-cell activators, such as interferon gamma, but not the accumulation of mRNA for interleukin- 1. 10 Therefore, treatment with critical doses of FK506 may cause a predominance of growth stimulators resulting in proliferation of smooth-muscle cells after the vessel endothelium has been damaged. High doses of FK506 may almost completely inhibit stimulation by cytokines of growth of smooth-muscle cells, thus preventing an acceleration of GVD. Our results suggest that GVD may occur in human allograft recipients treated with FK506. This effect has been seen only in rats, and proliferative vasculitis has not been noted in heart grafts in human beings treated with FK506. However, we must await the results of long-term follow-up because the peak incidence of GVD is 3 to 5 years after heart
transplantation.’1 This work
was
supported by the Peyton Hawes and Hedco foundations. REFERENCES
1. Billingham
ME. Cardiac
transplant atherosclerosis. Transplant Proc
1987; 16: 19-25.
ML, Hastillo A, Thompson A, et al. Lipid mediators in organ transplantation: does cyclosporine accelerate coronary atherosclerosis? Transplant Proc 1987; 19: 71. 3. Ochiai T, Sakamoto K, Gunji Y, et al. Effects of combination treatment with FK506 and cyclosporine on survival time and vascular changes in renal-allograft-recipient dogs. Transplantation 1989; 48: 193-97. 4. Calne RY, Collier DStJ, Lim S, et al. Rapamycin for immunosuppression in organ allografting. Lancet 1989; ii: 227. 5. Laden AM, Sinclair RA, Ruskiewicz M. Vascular changes in experimental cardiac allografts. Transplant Proc 1973; 5: 737-39. 6. Meiser BM, Morris RE. The importance of the spleen for the immunosuppressive action of cyclosporine in transplantation. Transplantation 1991; 51: 690-96. 7. Morris RE, Meiser BM, Wu J, Shorthouse R, Wang J. Use of rapamycin for the suppression of alloimmune reactions in vivo: schedule dependence, tolerance induction, synergy with cyclosporine and FK506, and effect on host-versus-graft and graft-versus-host reactions. Transplant Proc 1991; 23: 521-24. 8. Jonasson L, Holm J, Hannson GK. Cyclosporin A inhibits smooth muscle cell proliferation in the vascular response in injury. Proc Natl Acad Sci USA 1988; 85: 2303-06. 9. 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: 3677-84. 10. Tocci MJ, Matkovich DA, Collier KA, et al. The immunosuppressant FK506 selectively inhibits expression of early T cell activation genes. J Immunol 1989; 143: 718-26. 2. Hess
ADDRESSES:
Laboratory for Transplantation Immunology, Department of Cardiothoracic Surgery (B M Meiser, MD, R. E Morris, MD), and Department of Pathology (Prof M . E Billingham, FRCPath), Stanford University School of Medicine, Stanford, California, USA. Correspondence to Dr Bruno M Meiser, Department of Cardiac Surgery, University of Munich, Klinikum Grosshadern, Marchioninistrasse 15, 8000 Munich 70, Germany.
breathing during sleep
causes
J Appl Physiol 1986; 61:
upper 1438-43.
airway obstruction
in
humans.
4. Henke HG, Arias A, Skatrud JB, Dempsey JA. Inhibition of inspiratory muscle activity during sleep: chemical and nonchemical influences. Am Rev Respir Dis 1988; 138: 8-15. 5. Rodenstein DO, Stanescu DC, Delguste P, Liistro G, Aubert-Tulkens G. Adaptation to intermittent positive pressure ventilation applied through the nose during day and night. Eur Respir J 1989; 2: 473-78. 6. Heckmatt JZ, Loh L, Dubowitz V. Night-time ventilation in neuromuscular disease. Lancet 1990; 335: 579-82. 7. Meduri GU, Conoscenti CC, Menashe P, Nair S. Noninvasive face mask ventilation in patients with acute respiratory failure. Chest 1989; 95:
865-70.
Rehabilitation PhD), (P. Delguste, Electrophysiology (G. Aubert-Tulkens, MD), and Pneumology (D. O. Rodenstein, MD) Units, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium. Correspondence to Dr D O Rodenstein, Service de Pneumologie, Cliniques Universitaires Saint-Luc, Avenue Hippocrate 10, B-1200 Brussels, Belgium
ADDRESSES:
Effects of cyclosporin, FK506, and rapamycin on graft-vessel disease
Graft-vessel disease (GVD) limits the long-term survival of heart-transplant patients, and this effect has not been altered by use of cyclosporin for immunosuppression. We compared the effects of the immunosuppressants cyclosporin, FK506, and rapamycin on GVD in a rat-heart transplantation model. Allografted hearts from rats treated with 1 mg/kg FK506 for 50 days showed the same degree of myocardial rejection but a significantly worse (p<0·05) grade of GVD compared with grafted hearts from rats treated with 1·5 mg/kg cyclosporin for the same time. 2 mg/kg FK506 for 50 days
prevented cellular rejection but GVD was as severe as that found with 1 mg/kg FK506. Moderate GVD was present in two of five allografted hearts after treatment with 4 mg/kg FK506. 1·5 mg/kg rapamycin for 50 days was an effective inhibitor of rejection and GVD. Based on our results in rats, the possibility that GVD may occur in human hearttransplant recipients treated with FK506 cannot be excluded.
Despite immunosuppression with cyclosporin, graftvessel disease (GVD) remains the principal complication limiting the long-term survival of heart-transplant patients. The cause and pathogenesis of GVD are not well understood. Early angiographic detection of GVD is difficult’ because, unlike atherosclerosis in native coronary arteries, GVD is diffuse and occurs in small vessels before large coronary arteries. The need for improved suppressants of graft rejection led to identification of the structurally related macrolides-FK506 and rapamycin. Although many immunosuppressive activities of cyclosporin, FK506, and rapamycin have been described, the relative potencies and efficacies of these drugs for control of GVD have not been compared. Because cyclosporin increases serum cholesterol concentrations2 and because FK506 and rapamycin cause vasculitis in dogs,3,4 these drugs may potentially exacerbate GVD. We used a rat-heart transplantation model, in which lesions are produced that resemble GVD in man,’ to compare the effects of cyclosporin, FK506, and rapamycin on GVD. Hearts from Brown Norway or Lewis rats were transplanted into the abdomens of Lewis rat recipients’ and groups of five animals were treated daily with immunosuppressants or saline as shown in the table.* The extent of myocardial cellular rejection was graded on a scale from 0 to 3 on the basis of the extent of lymphocyte infiltration and myocyte necrosis. GVD was graded on a scale from 0 to 4 according to the severity of vessel injury. Differences between groups in grades of cellular rejection and of GVD were analysed by the Mann-Whitney U test (1-tailed).
cellular rejection and only slight GVD in hearts from rats treated with saline. Allografted isografted hearts from rats treated with 1 -5 mg/kg cyclosporin showed There
was no
lymphocyte infiltration and GVD was not significantly worse than in grafts from the saline-treated group (p > 0’05) (table). Treatment with 6 mg/kg cyclosporin abolished cellular rejection and GVD. Rapamycin (1-5 mg/kg) prevented cellular graft rejection and GVD (figure) as effectively as did 6 mg/kg of cyclosporin (p > 0-05). Allografted hearts from rats treated with 1 mg/kg FK506 showed the same degree of myocardial rejection (p > 0-05) but significantly worse GVD (p <0’05) compared with grafts from rats treated with 1-5 mg/kg cyclosporin. Although 2 mg/kg FK506 completely prevented cellular rejection, GVD was as severe (figure) as in grafts from rats treated with 1 mg/kg FK506 (p > 0-05). sparse
mg/kg
FK506 abolished GVD in three of the five transplanted hearts and two hearts showed moderate GVD 4
(both grade 2-0). Isograft recipients treated with 2 mg/kg FK506 for the first 50 days after transplantation had GVD that was as *Details of the administration of drugs, preparation of sections of heart tissue, and the blinded histological grading are available from The Lancet.
SCHEDULE AND OUTCOME OF TREATMENT WITH IMMUNOSUPPRESANTS IN RATS AFTER CARDIAC TRANSPLANTATION
1298
Photomicrographs of rat heart allograft tissue after 50 days of treatment with rapamycin or FK506.
Top: 15 mg/kg per day rapamycin, GVD = grade 0 (magnification x 250). Bottom 2 0 mg/kg per day FK506; GVD -grade 3 and there is interruption of the lamina and severe intimal proliferation (magnification x 350) extensive as that found in allografted hearts from rats treated with the same dose of drug (p > 0-05). When treatment with 2 mg/kg FK506 was delayed until day 51, and continued for 50 days thereafter, GVD was reduced in three of five transplanted hearts, two hearts still showed moderate GVD (grades 1 ’5 and 2-0). The effect of FK506 on recipients’ own hearts was assessed. Despite varying degrees of GVD in the different treatment groups, all native hearts were histologically normal. This study showed that neither cyclosporin nor rapamycin exacerbated GVD. Rapamycin is known to prolong allograft survival in rodents more potently and effectively than cyclosporin or FK506,7 and the present study showed that rapamycin was the most potent inhibitor of GVD. Cyclosporin inhibits smooth-muscle-cell proliferation induced by immune cells after mechanical injury to the endothelium,s and rapamycin might have similar effects. FK506 causes coronary arteritis in canine renal allograft recipients,3but in our study it did not cause vascular disease in native rat hearts. In allografted hearts, however, treatment with 1 mg/kg FK506 was associated with a GVD score nearly three times greater than that found with treatment with 1-5 mg/kg cyclosporin. 2 mg/kg FK506 completely inhibited cellular rejection, but GVD remained severe. The highest dose of FK506 abolished GVD in some, but not all, hearts. Minimal GVD developed in coronary vessels from saline-treated isografted hearts. In the absence of rejection, GVD in isografts is probably initiated by non-immune mechanisms. Endothelial cell damage (due, for example, to preservation, ischaemia, and reperfusion) seems to be the initial event that ultimately leads to GVD. Since FK506 exacerbated GVD in isografted hearts only when it was given immediately after surgery, and none of the native
hearts from recipients treated with FK506 exhibited any GVD, endothelial cell damage may be a prerequisite for induction of GVD by FK506. After 50 days, when the endothelium had recovered from initial damage, the ability of FK506 to induce GVD was significantly reduced. Additional immunological mechanisms may have a role in the development of GVD in allografts. It seems that cytokines and growth factors (eg, interleukin-1, tumour necrosis factor, and platelet-derived growth factor) produced by activated vessel-wall cells and infiltrating cells are important in the pathogenesis of GVD. Interferon inhibits smooth-muscle-cell however, gamma, proliferation.9 FK506 inhibits selectively the expression in vitro of mRNAs for the genes of early T-cell activators, such as interferon gamma, but not the accumulation of mRNA for interleukin- 1. 10 Therefore, treatment with critical doses of FK506 may cause a predominance of growth stimulators resulting in proliferation of smooth-muscle cells after the vessel endothelium has been damaged. High doses of FK506 may almost completely inhibit stimulation by cytokines of growth of smooth-muscle cells, thus preventing an acceleration of GVD. Our results suggest that GVD may occur in human allograft recipients treated with FK506. This effect has been seen only in rats, and proliferative vasculitis has not been noted in heart grafts in human beings treated with FK506. However, we must await the results of long-term follow-up because the peak incidence of GVD is 3 to 5 years after heart
transplantation.’1 This work
was
supported by the Peyton Hawes and Hedco foundations. REFERENCES
1. Billingham
ME. Cardiac
transplant atherosclerosis. Transplant Proc
1987; 16: 19-25.
ML, Hastillo A, Thompson A, et al. Lipid mediators in organ transplantation: does cyclosporine accelerate coronary atherosclerosis? Transplant Proc 1987; 19: 71. 3. Ochiai T, Sakamoto K, Gunji Y, et al. Effects of combination treatment with FK506 and cyclosporine on survival time and vascular changes in renal-allograft-recipient dogs. Transplantation 1989; 48: 193-97. 4. Calne RY, Collier DStJ, Lim S, et al. Rapamycin for immunosuppression in organ allografting. Lancet 1989; ii: 227. 5. Laden AM, Sinclair RA, Ruskiewicz M. Vascular changes in experimental cardiac allografts. Transplant Proc 1973; 5: 737-39. 6. Meiser BM, Morris RE. The importance of the spleen for the immunosuppressive action of cyclosporine in transplantation. Transplantation 1991; 51: 690-96. 7. Morris RE, Meiser BM, Wu J, Shorthouse R, Wang J. Use of rapamycin for the suppression of alloimmune reactions in vivo: schedule dependence, tolerance induction, synergy with cyclosporine and FK506, and effect on host-versus-graft and graft-versus-host reactions. Transplant Proc 1991; 23: 521-24. 8. Jonasson L, Holm J, Hannson GK. Cyclosporin A inhibits smooth muscle cell proliferation in the vascular response in injury. Proc Natl Acad Sci USA 1988; 85: 2303-06. 9. 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: 3677-84. 10. Tocci MJ, Matkovich DA, Collier KA, et al. The immunosuppressant FK506 selectively inhibits expression of early T cell activation genes. J Immunol 1989; 143: 718-26. 2. Hess
ADDRESSES:
Laboratory for Transplantation Immunology, Department of Cardiothoracic Surgery (B M Meiser, MD, R. E Morris, MD), and Department of Pathology (Prof M . E Billingham, FRCPath), Stanford University School of Medicine, Stanford, California, USA. Correspondence to Dr Bruno M Meiser, Department of Cardiac Surgery, University of Munich, Klinikum Grosshadern, Marchioninistrasse 15, 8000 Munich 70, Germany.