LECTURE
Low toxicity immunosuppressive protocols inrenal transplantation
Ron Shapiro
Department of Surgery, Director, Renal Transplantation, Thomas E. Starzl, Transplantation Institute
University of Pittsburgh, Pittsburgh, PA, USA(Received for publication on February 7, 2003)

Abstract. With the development of increasingly potent new immunosuppressive agents, the outcomes
after renal transplantation have continued to improve. However, patients continue to require long term
chronic immunosuppression. The toxicities associated with cyclosporine, azathioprine, prednisone, andanti-lymphocyte antibodies are well known; those associated with the newer agents, tacrolimus, mycophenolate mofetil, and sirolimus, have also been described. In an attempt to minimize these side
effects, a number of low toxicity protocols have been developed. They can be categorized into thosethat withdraw, minimize, or avoid calcineurin inhibitors, those that withdraw or avoid steroids, andthose that withdraw adjunctive (third) agents. This presentation will review the various low toxicity
protocols that have been utilized in clinical renal transplantation. While there are a number of combinations that have been tried, it is not yet clear which regimen(s) will prove to be the most efﬁcaciousand least toxic. In addition, the presentation will also describe preliminary outcomes with a new tolerogenic protocol developed at the University of Pittsburgh. This regimen combines steroid avoidancewith low doses and gradual tapering of calcineurin inhibitors, and has shown considerable promise in
kidney, pancreas, liver, and intestine recipients. (Keio J Med 53 (1): 18–22, March 2004)
Key words: low-toxicity, immunosuppression, renal transplant

mofetil, and sirolimus, all have well described toxicitiesof their own.5–18 The only two recently introduced
agents that seem to have few, if any toxicities, are theanti-IL2 receptor monoclonal antibodies, daclizumab
and basiliximab; however, both of these are useful for
induction only, and neither is being used as a maintenance immunosuppressive agent.19–24 Given these wellunderstood toxicities, there have been a number ofstudies over the years that have utilized regimens thathave attempted to minimize toxicity in transplant recipients. This review will focus on renal transplantation,
and will look at the ﬁve main areas that can be put into
the category of ‘‘low toxicity’’: calcineurin inhibitor
withdrawal, calcineurin inhibitor avoidance, steroid
withdrawal, steroid avoidance, and third agent withdrawal. These studies will be described chronologicallyin each group, and an attempt will be made to identify
the risks and beneﬁts associated with each particularregimen.

Introduction
Transplantation is fundamentally an unnatural act; atsome level, we were not meant to take an organ from
one individual and place it into another, with a reasonable expectation that it would function indeﬁnitely. The
modern reality, of course, is that we have been rather
successful in doing just that with a large number of different organs, and in spite of an imperfect understanding of the immune system. We have been successful
because of the development of effective chemical andbiological immunosuppressive agents. Although someof these agents have been relatively selective, all are
non-speciﬁc, and virtually all have side effects. The
toxicities associated with the conventional agents,
namely cyclosporine, steroids, azathioprine, and antilymphocyte preparations, are well understood and havebeen extensively described.1–5 Similarly, the newer
immunosuppressive agents, tacrolimus, mycophenolate

Presented at the 1304th Meeting of the Keio Medical Society in Tokyo, December 14, 2002.
Reprint requests to: Dr. Ron Shapiro, Department of Surgery, Director, Renal Transplantation, Thomas E. Starzl, Transplantation Institute,
University of Pittsburgh, Pittsburgh, PA 15260, USA
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Keio J Med 2004; 53 (1): 18–22

Calcineurin Inhibitor-Sparing
Calcineurin inhibitor withdrawal
The ﬁrst major study on calcineurin inhibitor withdrawal came early in the development of cyclosporine.
In Oxford, England, Peter Morris’ group took patients who had initially been placed on cyclosporineand converted them three months after transplantation
to azathioprine/prednisone. Sixty-four patients werestudied. While there was improvement in renal functionin this group of patients, there was also a 32% incidenceof acute rejection, with 2 graft losses. Thus, this earlyexperience was not favorable.25–27 A subsequent
randomized trial, from Glasgow, in 102 patients,
randomized patients to conversion to azathioprinebased therapy one year after transplantation. With 10
years of follow up, there was no difference in the 10year patient or graft survival, although there was an
early increased incidence of rejection in the patients
converted to azathioprine. Advantages in the azathioprine group included lower serum creatinine levels anda lower requirement for antihypertensive medication.28
Kasiske in Minnesota performed a meta-analysis of
cyclosporine withdrawal studies, looking at 10 randomized and 7 non-randomized trials. He found an increased incidence of rejection after conversion to azathioprine, but no difference in short-term patient orgraft survival.29
With regard to the newer third agents, at least two
trials of conversion from cyclosporine to MMF havebeen performed, in the Netherlands and in France; bothhave shown reasonably good outcomes in small numbers of patients.
A large, prospective, randomized trial looking at the
combination of cyclosporine, sirolimus, and steroids,
was performed. Patients were randomized to continue
with this regimen or to undergo cyclosporine withdrawal beginning three months after transplantation.
With one-year follow up, patient survival, graft survival,
and the incidence of rejection were similar between thetwo groups. The patients randomized to cyclosporine
withdrawal had better renal function.
Reduced Dose Calcineurin Inhibitor
An additional category of studies has looked at reducing cyclosporine dosages as opposed to complete
withdrawal. The group in Barcelona studied patientswith cyclosporine nephrotoxicity and looked at the impact of reducing the dosage by nearly half, with theconcomitant introduction of mycophenolate mofetil.
Renal function improved, as did blood pressure and
TGF beta levels, and no rejection was noted.

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Another study looked at the impact of reduced dose
cyclosporine with sirolimus and steroids, and compared
the outcomes to those in patients receiving full dose
cyclosporine with sirolimus and steroids. Although theoverall incidence of rejection was somewhat higher,
increasing from 8.5% to 19.5%, much of the impact of
this increased incidence of rejection was in African
Americans. The incidence of rejection in non-African
Americans receiving reduced dose cyclosporine withsirolimus was 11%, whereas in African-Americans it
was 39%. This study had 149 patients.
A smaller, non-randomized study looking at the
combination of basiliximab, sirolimus, and steroids withthe delayed introduction of low dose cyclosporine,
found, in 40 patients, excellent patient and graft survival rates, an incidence of rejection of 16%, and an
incidence of steroid-resistant rejection of 2%.
A few studies have been performed looking at the
combination of low dose tacrolimus with sirolimus andsteroids, from Halifax, Cleveland, and Pittsburgh. In
general these trials have shown excellent patient andgraft survival rates, with relatively low incidences ofrejection, and reasonable renal function; cholesterollevels in the Pittsburgh study were under 200 mg/dl.
Calcineurin Inhibitor Avoidance
A number of studies have been performed in thiscategory, looking at combinations of antibody andmycophenolate mofetil, sirolimus and azathioprine,
sirolimus and mycophenolate mofetil, antibody withsirolimus and mycophenolate mofetil, and antibody
with sirolimus monotherapy.
The ﬁrst study performed looked at the combinationof daclizumab, mycophenolate mofetil, and prednisone,in 98 patients. Although excellent patient and graft
survival was seen, the incidence of rejection was 48%,and 62% of the patients in the trial were started on
calcineurin inhibitors.
A smaller trial, utilizing antithymocyte globulin,
mycophenolate mofetil, and steroids in 17 patients,from Barcelona, had excellent patient and graft survival, with a need for calcineurin inhibitors in 30% of
the patients.
Two European randomized trials utilizing sirolimus
as the main maintenance immunosuppressive agent
have been performed. One compared sirolimus, azathioprine, and steroids with cyclosporine, azathioprine,and steroids. The other compared sirolimus, mycophenolate mofetil, and steroids with cyclosporine, mycophenolate mofetil, and steroids. In both trials, comparable patient and graft survival was noted between thesirolimus and the cyclosporine groups, and a comparable incidence of rejection was noted. Renal function
was better in the patients treated with sirolimus, and20

Shapiro R: A tolerogenic regimen for renal transplants

less hypertension was noted, but cholesterol levels andtriglyceride levels were elevated, and platelet counts
were also lower.
A recent study from Cleveland looked at basiliximab, sirolimus, mycophenolate mofetil, and steroids in
31 patients, with excellent patient and graft survival andan incidence of rejection of less than 10%. Cholesterollevels were elevated, as were triglyceride levels.
Two small trials have been performed utilizing the
combination of Campath 1-H with sirolimus monotherapy; 15 patients have been studied at the NIH and
24 at the University of Wisconsin. This combination
certainly appears to be promising, although one allograft has been lost to rejection in the Wisconsin series.
Rejection of an atypical type has been seen routinely in
the NIH series, and histologically typical rejection has
been seen in 25% of the Wisconsin series. This research, avoiding both calcineurin inhibitors and steroids, is quite promising.

adults and over 90% of children. Predictably, over 20%of the patients withdrawn from steroids had to havesteroids resumed because of late rejection. Five year
patient survival has not been different in the adults
withdrawn from and restarted on steroids, although
graft survival has been worse, compared to the group
discontinuing steroids and not needing to resume them.
In pediatric patients there has been no difference in ﬁve
year patient or graft survival between the children
withdrawn from steroids or those who had resume steroids, although renal function was worse in the patients
who resumed steroids. In both adults and children, theworst outcomes were in the patients who were neverwithdrawn from steroids; they obviously represented ahigher risk group, and had more early rejection anddelayed graft function than the groups withdrawn fromsteroids.

Steroid Sparing Regimens

In this category, one of the early studies was performed over 20 years ago in Europe, comparing patients randomized to cyclosporine monotherapy or toazathioprine and prednisone. Five-year graft survival
was 55% in cyclosporine patients and 40% in the azathioprine patients; however, 47% of the cyclosporinetreated patients had steroids added to the maintenanceimmunosuppression. A randomized trial in Englandcomparing cyclosporine monotherapy, cyclosporine/
steroids, and azathioprine/prednisone in 465 patients,
with a follow up of seven years, showed no differencesin patient or graft survival between the two cyclosporine groups; 15% of the cyclosporine monotherapy
group had steroids added to the immunosuppressive
regimen.
More recent studies, out of Minnesota, have looked
at a 5 day course of Thymoglobulin, cyclosporine,
mycophenolate mofetil, and six days of steroids postoperatively, in 51 patients, with excellent patient andgraft survival, and an incidence of rejection of less than10%.
In a trial from Cambridge, England, 31 patients were
given two doses of campath 1-H and low dose cyclosporine monotherapy, with excellent patient and graft
survival and a relatively low incidence of rejection of
19%. A three-year analysis of this series has continued
to show excellent medium term outcomes, with 97%
patient survival and 85% graft survival.
Studies with tacrolimus-based therapy have lookedat the combination of tacrolimus, mycophenolate mofetil, and one week of steroids, with excellent three-year
outcomes; the incidence of rejection was 25%, and 85%of the patients remained off prednisone. This study was
performed on 52 patients and was from the Universityof Chicago.

Steroid withdrawal
A number of trials have looked at steroid withdrawal
in renal transplant recipients. One of the early important, and somewhat discouraging studies, was a Canadian randomized multicenter trial, which randomized
patients to withdrawal three months after transplantation (n ¼ 260) or to alternate day steroids (n ¼ 263).
Patient survival at ﬁve years was comparable, butallograft survival in the group randomized to steroid
withdrawal was signiﬁcantly inferior, 73%, compared to
the group that remained on every other day steroids,
85% (p ¼ .03). A more recent randomized multicenter
trial of steroid withdrawal under cyclosporine andmycophenolate mofetil based therapy (n ¼ 266) was
stopped by its Data Safety and Monitoring Board, because of the increased incidence of rejection in thepatients randomized (beginning three months after
transplantation) to steroid withdrawal. Again, a moredetailed analysis suggests that while the patientsrandomized to continue on steroids had an incidence ofrejection of 10%, and the group randomized to steroid
withdrawal had an incidence rejection of 31%, within
the group of patients randomized to steroid withdrawal,
non African-Americans had an incidence of rejection of
16%, and African-Americans had an incidence of rejection of 40%. There was no difference in one year
patient or graft survival between the steroid withdrawal
and steroid continuation group.
Under tacrolimus-based therapy, retrospective nonrandomized studies from the University of Pittsburgh in
795 adults and 82 pediatric patients have demonstrated
an ability to withdraw steroids routinely in 71% of

Steroid Avoidance/Near-AvoidanceKeio J Med 2004; 53 (1): 18–22

Another study, looking at 192 patients at randomized to daclizumab, tacrolimus, MMF, and just threedoses of steroids, was associated with nearly perfectpatient and graft survival and an incidence of rejectionof 14%. Subsequent studies from this group havelooked at six days of steroids with Thymoglobulin induction, tacrolimus, and MMF or sirolimus, with excellent outcomes and essentially no rejection, in kidneypancreas recipients.
Two studies in pediatric patients have been performed, one from Denmark, and one from Stanford.
The Danish study included 14 patients who received
antithymocyte globulin, cyclosporine, and in half ofthe patients, mycophenolate mofetil. There were threepatients who experienced rejection, for an incidence of
21%. The initial Stanford study looked at 10 patients
receiving daclizumab, tacrolimus, and either MMF or
sirolimus; the daclizumab was continued for an extended period of time. No clinical rejection was seen inthese patients, and a 20% incidence of sub-clinical rejection was noted.
A ﬁnal study has been initiated in Pittsburgh, looking at Thymoglobulin preconditioning with tacrolimus
monotherapy and steroid avoidance post transplantation, in a number of different organ recipients. The follow up on these patients is quite short, but the majorityof the patients appear to be able to tolerate this regimen well, and tapering of tacrolimus dosing to as low as
twice a week has been attempted in some patients. Thislatter experience, obviously, will require more follow up.
Third Agent Sparing
Azathioprine withdrawal
In this section there are two studies, one from
Knoxville, Tennessee (n ¼ 103), and one from Iowa
City, Iowa (n ¼ 129). In both studies azathioprine was
successfully withdrawn from stable renal transplantpatients, without an increased incidence of acute or
chronic rejection or deterioration in graft survival.
Conclusions
There have been a large number of studies that haveattempted to look at reduced toxicity immunosuppressive regimens. A number of combinations have been
tried, and many of them have been extremely successful, particularly in low risk recipients. Ultimately, it is
not yet clear which regimen(s) will be the most effectivefrom the point of view of maximizing patient and graft
survival, minimizing rejection, and minimizing adverse
events. It is likely that there will be several reasonablecandidate regimens that will emerge over the next several years. Important questions will be long-term out-

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comes, looking especially at half-lives and chronic
rejection on the one hand and the development of adverse side effects on the other. What is encouraging
from the point of view of both transplant patients andthose caring for them is that a number of low toxicity
options exist, as increasing numbers of agents become
available.
References
1. Fung JJ: Conventional immunosuppressive agents, In: Shapiro
R, Simmons RL, Starzl TE, eds, Renal Transplantation, Stamford, Appleton & Lange, 1997; 183–194
2. McCauley J: Medical complications, In: Shapiro R, Simmons RL,
Starzl TE, eds, Renal Transplantation, Stamford, Appleton &Lange, 1997; 299–314
3. Myers BD, Sibley R, Newton L, Tomlanovich SJ, Boshkos C,
Stinson E, Luetscher JA, Whitney DJ, Krasny D, Coplon NS,
et al: The long-term course of cyclosporine-associated chronic
nephropathy. Kidney Int 1988; 33: 590–600
4. Kasiske BL, Tortorice KL, Heim-Duthoy KL, Awni WM, Rao
KV: The adverse impact of cyclosporine on serum lipids in renaltransplant recipients. Am J Kidney Dis 1991; 17: 700–707
5. Porter GA, Bennett WM, Sheps SG: Cyclosporine-associatedhypertension. National High Blood Pressure Education Program. Arch Intern Med 1990; 150: 280–283
6. Shapiro R: Clinical experience with new immunosuppressive
agents in renal transplant recipients. In: Shapiro R, Simmons
RL, Starzl TE, eds, Renal Transplantation, Stamford, Appleton& Lange, 1997; 195–218
7. Pirsch JD, Miller J, Deierhoi MH, Vincenti F, Filo RS: A comparison of tacrolimus (FK506) and cyclosporine for immunosuppression after cadaveric renal transplantation. FK506 Kidney
Transplant Study Group. Transplantation 1997; 63: 977–983
8. Mayer AD, Dmitrewski J, Squifﬂet JP, Besse T, Grabensee B,
Klein B, Eigler FW, Heemann U, Pichlmayr R, Behrend M, et al:Multicenter randomized trial comparing tacrolimus (FK506) andcyclosporine in the prevention of renal allograft rejection: a report of the European Tacrolimus Multicenter Renal Study
Group. Transplantation 1997; 64: 436–443
9. Jensik SC: Tacrolimus (FK506) in kidney transplantation: threeyear survival results of the US multicenter, randomized, comparative trial. FK506 Kidney Transplant Study Group. Transplant Proc 1998; 30: 1216–1218
10. Neylan JF: Racial differences in renal transplantation after immunosuppression with tacrolimus versus cyclosporine. FK506
Kidney Transplant Study Group. Transplantation 1998; 65: 515–
523
11. European Mycophenolate Mofetil Cooperative Study Group:
Placebo-controlled study of mycophenolate mofetil combinedwith cyclosporin and corticosteroids for prevention of acute rejection. Lancet 1995; 345: 1321–1325
12. Sollinger HW: Mycophenolate mofetil for the prevention of
acute rejection in primary cadaveric renal allograft recipients.
U.S. Renal Transplant Mycophenolate Mofetil Study Group.
Transplantation 1995; 60: 225–232
13. The Tricontinental Mycophenolate Mofetil Renal Transplantation Study Group: A blinded, randomized clinical trial of mycophenolate mofetil for the prevention of acute rejection in
cadaveric renal transplantation. Transplantation 1996; 61: 1029–
1037
14. Wiesel M, Carl S: A placebo controlled study of mycophenolate
mofetil used in combination with cyclosporine and cortico-

22

15.

16.

17.

18.

19.
20.

21.

Shapiro R: A tolerogenic regimen for renal transplants
steroids for the prevention of acute rejection in renal allograft
recipients: 1-year results. The European Mycophenolate Mofetil
Cooperative Study Group. J Urol 1998; 159: 28–33
Mathew TH: A blinded, long-term, randomized multicenter
study of mycophenolate mofetil in cadaveric renal transplantation: results at three years. Tricontinental Mycophenolate Mofetil Renal Transplantation Study Group. Transplantation 1998;
65: 1450–1454, Erratum in: Transplantation 1998; 66: 817
Kim YS, Moon JI, Kim SI, Park K: Clear beneﬁt of mycophenolate mofetil-based triple therapy in reducing the incidence ofacute rejection after living donor renal transplantations. Transplantation 1999; 68: 578–581
van Gelder T, Hilbrands LB, Vanrenterghem Y, Weimar W, deFijter JW, Squifﬂet JP, Hene RJ, Verpooten GA, Navarro MT,
Hale MD, Nicholls AJ: A randomized double-blind, multicenterplasma concentration controlled study of the safety and efﬁcacy
of oral mycophenolate mofetil for the prevention of acute rejection after kidney transplantation. Transplantation 1999; 68: 261–
266
Kahan BD, Julian BA, Pescovitz MD, Vanrenterghem Y, Neylan
J: Sirolimus reduces the incidence of acute rejection episodes
despite lower cyclosporine doses in caucasian recipients of mismatched primary renal allografts: a phase II trial. Rapamune
Study Group. Transplantation 1999; 68: 1526–1532
Nashan B: The interleukin-2 inhibitors and their role in lowtoxicity regimens. Transplant Proc 1999; 31: 23S–26S
Vincenti F, Kirkman R, Light S, Bumgardner G, Pescovitz M,
Halloran P, Neylan J, Wilkinson A, Ekberg H, Gaston R, Backman L, Burdick J: Interleukin-2-receptor blockade with daclizumab to prevent acute rejection in renal transplantation. Daclizumab Triple Therapy Study Group. N Engl J Med 1998; 338:
161–165
Nashan B, Moore R, Amlot P, Schmidt AG, Abeywickrama K,
Soulillou JP: Randomised trial of basiliximab versus placebo for

22.

23.

24.

25.

26.

27.

28.

29.

control of acute cellular rejection in renal allograft recipients.
CHIB 201 International Study Group. Lancet 1997; 350: 1193–
1198, Erratum in: Lancet 1997; 350: 1484
Nashan B, Light S, Hardie IR, Lin A, Johnson JR: Reduction of
acute renal allograft rejection by daclizumab. Daclizumab Double Therapy Study Group. Transplantation 1999; 67: 110–115
Hengster P, Pescovitz MD, Hyatt D, Margreiter R: Cytomegalovirus infections after treatment with daclizumab, an anti IL-2
receptor antibody, for prevention of renal allograft rejection.
Roche Study Group. Transplantation 1999; 68: 310–313
Kahan BD, Rajagopalan PR, Hall M: Reduction of the occurrence of acute cellular rejection among renal allograft recipientstreated with basiliximab, a chimeric anti-interleukin-2-receptor
monoclonal antibody. United States Simulect Renal Study
Group. Transplantation 1999; 67: 276–284
Morris PJ, French ME, Dunnill MS, Hunnisett AG, Ting A,
Thompson JF, Wood RF: A controlled trial of cyclosporine inrenal transplantation with conversion to azathioprine and prednisolone after three months. Transplantation 1983; 36: 273–277
Chapman JR, Morris PJ: Cyclosporine nephrotoxicity and theconsequences of conversion to azathioprine. Transplant Proc
1985; 17 (4 Suppl 1): 254–260
Morris PJ, Chapman JR, Allen RD, Ting A, Thompson JF,
Dunnill MS, Wood RF: Cyclosporin conversion versus conventional immunosuppression: long-term follow-up and histologicalevaluation. Lancet 1987; 1: 586–591
MacPhee IA, Bradley JA, Briggs JD, Junor BJ, MacPherson SG,
McMillan MA, Rodger RS, Watson MA: Long-term outcome ofa prospective randomized trial of conversion from cyclosporine
to azathioprine treatment one year after renal transplantation.
Transplantation 1998; 66: 1186–1192
Kasiske BL, Heim-Duthoy K, Ma JZ: Elective cyclosporine
withdrawal after renal transplantation. A meta-analysis. JAMA
1993; 269: 395–400