De fi ning a Steroid Withdrawal Protocol in a newly established Kidney Transplantation Unit

Chitungwiza Central Hospital, a 500 bedded tertiary teaching hospital located in the city of Harare in the Southern African country of Zimbabwe, is at an advanced stage of establishing a kidney transplantation unit with the guidance of International Society of Nephrology. It is anticipated that the unit will initially perform at least fi ve (5) kidney transplant operations per month when it becomes fully functional. The recommended immunosuppression protocol includes induction by rabbit anti-thymocyte globin (rATG) and maintenance on prednisolone, tacrolimus (TAC) and mycophenolate mofetil (MMF), and does not consider steroid withdrawal. This review is aimed to critically review our unit’s recommended policy of maintaining steroids as part of immunosuppression versus steroid withdrawal strategies implemented by other kidney transplant units. The review considers the advantages and disadvantages of various steroid withdrawal or avoidance protocols using published evidence.


Introduction
Chitungwiza Central Hospital, a 500 bedded tertiary teaching hospital located in the city of Harare in the Southern African country of Zimbabwe, is at an advanced stage of establishing a kidney transplantation unit with the guidance of International Society of Nephrology.It is anticipated that the unit will initially perform at least fi ve (5) kidney transplant operations per month when it becomes fully functional.The recommended immunosuppression protocol includes induction by rabbit anti-thymocyte globin (rATG) and maintenance on prednisolone, tacrolimus (TAC) and mycophenolate mofetil (MMF), and does not consider steroid withdrawal.This review is aimed to critically review our unit's recommended policy of maintaining steroids as part of immunosuppression versus steroid withdrawal strategies implemented by other kidney transplant units.The review considers the advantages and disadvantages of various steroid withdrawal or avoidance protocols using published evidence.

Abstract
As a key step in setting up the immunosuppression protocols for our kidney transplantation unit, still in its infancy, consideration of the choice of the steroid withdrawal strategy is important.We conducted a review of literature to ascertain a safe steroid withdrawal protocol that would be able to achieve a high allograft survival and function rate, low acute allograft rejection (AR) rate and advantageous in reducing a wide range of adverse effects associated with corticosteroids such as cardiovascular risks, growth retardation in pediatric patients, osteoporosis and other steroid-related complications.
Based on this review, steroid withdrawal was associated with high rates of AR in comparison to steroids maintenance.Specifi cally, late steroid withdrawal was related to poor outcomes in comparison to total steroid avoidance or very early withdrawals.High immunological risk patients with delayed graft function, prolonged cold ischemia time, donation after cardiac death, black race and those with a history of glomerulonephritis are not recommended for steroid avoidance.
Due to the unclear reduction of adverse effects and co-morbidities through steroid withdrawal or avoidance and inconclusive results and outcomes surrounding this subject which still needs further refi nement, the decision taken by our unit was to retain, taper and maintain a very low dosage of corticosteroids on a long term basis with combined use of lymphocyte depleting induction agents coupled with calcineurin inhibitors and anti-proliferative agents for maintenance.Transplant recipients with low immunological risk are ideal candidates for early steroid withdrawal.
since the early sixties.Irrespective of their capability in preventing acute rejection, steroids are known to be associated with adverse effects including weight gain, osteoporosis, cataracts, glaucoma, skin atrophy, diabetes mellitus, hyperlipidaemia, avascular necrosis, myopathy and increased infection risk [1,2,3].In order to reduce the adverse effects, clinicians tended to reduce the dosages of steroids in immunosuppression.Steroid-free immunosuppression was possible since the introduction of calcineurin inhibitors (CNI) such as cyclosporine A (CsA) [3].

Immunosuppression
protocols include induction, maintenance regimen and rescue regimen.Induction immunosuppression might include lymphocyte depletion therapy or through supplementary immunosuppressive agents like interleukin-2 (IL-2) receptor antibody.Induction has been shown to reduce AR.The maintenance immunosuppression includes a calcineurin inhibitor such as CsA or TAC, antiproliferative agent such as MMF or azathioprine (AZA) and a corticosteroid [1].Steroids promote the activity of uridine diphosphate in mycophenolic acid metabolism.This activity is, however, reversed when steroids are withdrawn thus leading to an accumulation of mycophenolic acid due to its poor clearance resulting in the untoward effects on the recipient's immunosuppression due to steroid discontinuation [4,5].Corticosteroids have been considered to inhibit T cell signals, which are responsible for apoptosis.As they reduce the cytokine release, corticosteroids possibly amplify cytokine receptors expression on T Cells.Therefore, a later withdrawal after an initial treatment with steroids may cause a T Cell activation rebound, resulting in AR due to the release of cytokine as a result of upregulated cytokine receptors [6].By this review we aim to establish the most suitable steroid withdrawal protocol for renal transplant recipients.

Defi nitions
Reducing exposure to steroids can be accomplished through steroid avoidance where the steroids are withdrawn very early within the fi rst few days up to 14 days following transplantation or through steroid withdrawal wherein the steroids are discontinued at a particular time well after the transplantation.Steroid withdrawal at 3-6 months after transplantation is categorized as early withdrawal while withdrawal after 6 months and above after transplantation is considered as late withdrawal [1,7].

Early steroid withdrawal
Reports emanating from the CsA era confi rm a high AR rates in renal transplant patients on CsA and AZA when early steroid withdrawal was applied [4,8,9].A random Canadian placebo controlled trial of 523 renal transplant patients recommended for a 5 year follow up to have an in depth assessment of steroidfree protocols.That study showed a reduction in graft survival rates to 73% in patients on CsA therapy who had stopped steroid intake at 3 months after transplantation as compared to a higher fi gure of 85% survival in study cases who did not discontinue prednisolone intake [4,10].Hricik et al., in 1993 demonstrated in a meta analysis that avoidance of steroids at transplantation or withdrawing post transplantation intensifi ed AR risk, however with no adverse effect on graft survival [11].
In a double-blinded European multicentre random study of 500 kidney transplant recipients, corticosteroids were administered to one group at half the dose for 3 months from the transplantation date and then stopped while standard doses were maintained in a control group.CsA and MMF were administered to both groups and after the 6 and 12 months the group on half dosage had a relatively higher percentage of AR proven by biopsy (23% and 25%, respectively) than the control group (14% and 15%, respectively).At 12 months, the graft loss rate in the half dose group was 5% in comparison to 4% in the control group, please see table 1 [9].A similar study in the USA in contrast experienced a massive increase in AR rate in the half dose group.The AR mostly affected African American recipients in the study [12].
Hricik et al., also noted risk of AR in recipients of black race and early withdrawal as risks associated [13].In a follow up uncontrolled study by Hricik et al., prednisolone was withdrawn at 3 months post transplantation from those African-American patients who had been commenced on sirolimus, tacrolimus, and corticosteroid as the initial treatment and had not experienced any AR.In this study there was AR in 7% of patients that raised concerns.It was concluded that there is need to be cautious about withdrawal of steroids in African-American patients irrespective of them being on strong immunosuppression [14].
Vanrenterghem et al., set up a multicenter Random Clinical Trial (RCT) of 556 low risk renal transplant recipients who were maintained on TAC and MMF.In a group of patients steroids were withdrawn at 3 months.On review of the cases at 6 months, an increased AR rate and reduced cholesterol and low density lipoprotein (LDL) were noted in the steroid withdrawal group commencing from the period 3 up to 6 months post transplantation, refer to table 1 [7,15].Pascual et al. in 2011, showed that steroid avoidance or early withdrawal within the fi rst 14 days after transplant was safe in recipients who are on an anti-interleukin T receptor antibodies or ATG induction and TAC and MMF treatment [16].In another systematic review of 1820 study cases with no induction, where steroids withdrawn at 3 and 6 months post transplantation, Pascual et al., deduced that for at least 3 years following transplantation, renal graft and patient survival were not infl uenced by steroid withdrawal, however, where patients were on CsA maintenance treatment, the incidence of AR were increased, please see table 1 [17].

Late steroid withdrawal
In a study by Reisman et  Group, where steroids were withdrawn beyond 6 months post transplantation demonstrated that it was more benefi cial to withdraw steroids as graft and patient survival were improved.
There was no variation in AR between patients who continued on steroids and those who where withdrawn.Cardiovascular risk was notably reduced [23].
Late stage steroid withdrawal at 5 to 6 months in patients on TAC and MMF maintenance, was reviewed after a 5 year follow up and recommended as being safe with a low risk of allograft failure and AR following studies in 50 patients by Loucaidou et al (2005) [24].
In 2017 Haller et al., carried out a retrospective study on the optimal period for steroid withdraw post transplantation.They evaluated 6070 patients who had received kidney transplants for the fi rst time in the Austrian Dialysis and Transplant Registry.1131 patients had graft loss, 821 study cases had deceased following withdrawal of steroids within 18 months subsequent to transplantation after induction with anti-IL2.There was a confi rmed link to high graft loss in comparison to steroid maintenance [25].

Steroid avoidance
The combined use of polyclonal anti-T cell antibodies, biological agents and CNIs has seen a marked reduction of AR.In order to withdraw steroids at an early stage after transplantation, a strong induction immunosuppression is necessary in order to avoid increased rates of AR.The justifi cation for early withdrawal or avoidance being that if steroid withdrawal is effected several weeks or months after transplantation the likelihood of provoking acute rejection would be increased, please read table 3 [15,26].

Kuypers et al., in a comparison of daclizumab induction, low
dose TAC and MMF and steroid withdrawal against standard regime of TAC, MMF and steroids, the patients who were withdrawn from steroids at 5 months had less AR and their graft function was better in study group than in the patients on standard regimen [27].
Polyclonal rabbit antithymocyte globulin was used together with MMF and CsA in living related donor graft where steroids were stopped 5 days after transplantation.87% of the patients in this study by Mattas et al (2004) did not experience any AR at 12 months post transplantation and kidney function was comparable to control patients on standard therapy without induction [28].This steroid-free immunosuppressive protocol also demonstrated a high patient and graft survival rates and high acute and chronic rejection free graft survival rates [29].
The rate of AR proven by biopsy at 12 months insignifi cantly varied in a steroid withdrawal patient study pool (20%) and those on standard immunosuppression (16%) when the effectiveness of basiliximab added to a CsA and MMF was checked in early corticosteroid withdrawal 4 days post transplantation by Vincenti et al., in a study comprising 83 patients.Graft survival was 100% in the steroid withdrawal group [30].on alemtuzumab induction, and maintenance with low dose TAC, MMF and no steroids while an equal number was assigned to basiliximab treatment and maintenance with standard dose TAC, MMF and steroids.At 6 months, there was a reduction by 58% of biopsy proven AR in the alemtuzumab group, please note fi gure 1. Graft failure and patient survival did not vary in the two study groups [7,34].
In a similar study utilizing 335 low risk patients, Hanaway et al (2011) carried out a clear cut comparison between alemtuzumab and basiliximab where steroids were withdrawn at day 5.The outcome of this study showed a low biopsy proven acute rejection rate in the alemtuzumab participants after 3 years [7,35].
ter Meulen et al., studied the possibility of withdrawing steroids as early as 3 days following transplantation and while using anti 1L-2R induction with TAC and MMF.At 12 months the study revealed no difference in AR confi rmed by biopsy between daclizumab group (15%) and control group (14%) [23].The survival of grafts in the 2 groups was not different at 12 months [2,36].
Complete steroid avoidance was studied by Birkeland et al., in 100 children following a 10 day induction with ATG and CsA and maintenance with MMF.From this study AR was low at 13% and graft survival was 82% at 4 years [37].
Where daclizumab was used by Sarwal et al., instead of steroids in a TAC and MMF protocol, in paediatric graft recipients, no acute rejection or signs of chronic rejection were recorded [38].
In .This protocol accordingly also has a low rate of acute rejection including in African-Americans.The rate at which early steroid withdrawal was being applied, emphasized the importance of safety and in which patient group it should be applied [2].
In addition to the unclearness of the current data, the strategies of steroid withdrawal are now strongly established at most kidney transplant centres and the trend of steroid free protocols started being prominent since 2000 where at least 5% of patients were discharged after transplantation without steroids.This fi gure increased to at least 23% by 2004 [39].The issue of timing of steroids withdrawal and how long the outcomes be observed are critical factors in evaluating the advantages and harms of steroid withdrawal in kidney transplant recipients.A cut off of 14 days was common in steroid withdrawal and steroid avoidance, however, most of the steroid avoidance groups administered steroids for at least seven days or less while the bulk of withdrawal studies phased out steroids from three to six months post transplantation.Most studies had a short follow up period following steroid withdrawal or avoidance thus inhibiting fi nalization concerning lifelong complications for recipient and graft survival.AR has a major infl uence on graft survival and it is well known that recurrence of AR in most cases leads to allograft loss.In this review, AR occurred generally in the fi rst year after transplantation, however, the harms of steroid withdrawal may stay undetected for up to fi ve years.Therefore, the harmful after effects following steroid withdrawal on lifelong graft survival could not be dismissed on the basis of these studies.Equally so there is a need to build more evidence on adverse effects including infections.There is a general agreement amongst 3 studies on steroid withdrawal and 4 studies on steroid avoidance in patients on CsA with or without AZA that there is a high rate of AR in recipients withdrawn from steroids in comparison to those who were not taken off steroids [1].Mudge in 2016 commented on the Haller et al 2016 review, that both steroid avoidance and withdrawal result in higher rate of AR [41].In this study 68% of the patients were on ATG induction while 32% were on IL-2 receptor blocking monoclonal antibodies.All patients were on TAC and MMF maintenance.There results of the study after 5 years showed no variation in patient and graft survival with the group that continued steroid intake having a low biopsy proven AR.In the steroid withdrawal arm, the patients inducted with ATG had an insignifi cant reduction of AR rate than with IL-2 receptor blocking monoclonal antibodies.

Low steroid dose maintenance
While creatinine clearances were the same between the two study groups at 5 years, there was a very high prevelance of chronic allograft nephropathy in the steroid withdrawal group than in the patients that continued with steroid treatment.
Very early withdrawal had an insignifi cant variation in new onset diabetes mellitus, hypertension total cholesterol and low density lipoprotein but had a signifi cant improvement in serum triglycerides.Bone fractures and avascular necrosis were lowered while subcapsular cataracts were increased [7,42].
The conclusion that patients on steroid avoidance or withdrawal had a statistically high AR rate compared to those patients maintained on steroids was reached in a meta-analysis study by Knight et al., comprising of 5637 patients.In this study allograft function was improved in patients on steroid continuation.Hypertension, new onset diabetes mellitus and hypercholesterolemia were decreased with steroid avoidance [7,43].high immunological risk studies, the AR rates were moderate at 13-14% with a remarkably improved graft and patient survival being recorded.However, there is still need for further verifi cation on the consistence of this type of management protocol [44][45][46][47].

Steroid minimization and high immunological risk
Another trial included high immunological risk patients who Outcomes were not different between two comparative groups [1].
Citation: Moyo  function or donor reactive cellular immunity to be identifi ed at the time of transplantation for steroid maintenance [49][50][51].Recurrence of some glomerulopathies following steroid avoidance has been noted to be higher than with steroid continuation.Patient and graft survival was not affected in patients inducted on rATG and maintained on TAC and MMF [44,52].In a study comprising 124 kidney transplant recipients, of whom 91% were on rATG induction Visger et al., also had the same results as shown by Kuklan [44,53].Generally in patients where the initial cause of kidney disease is IgA nephropathy, steroid avoidance is not recommended.

Steroid minimization in the elderly and other conditions
Steroid minimization is considered as being non-benefi cial to elderly patients since the rates of AR are already reduced in elderly persons.Steroid withdrawal in the elderly needs to be cautiously and carefully applied as it may lead to bad outcomes including harsh AR.Additionally, due to their limited life expectancy steroid minimization advantages on cardiovascular disease becomes irrelevant [7,59].In their review Yarlagadda et al (2009) reported that ischemic injury in kidney transplant recipients with delayed graft function and prolonged cold ischemia time is linked to acute rejection.This makes this category of patients not attractive for steroid minimization [7,60].

Novel immunotherapy and steroid avoidance
A few trials have been carried out on novel immunosuppresion protocols that do not include steroids and CNI.89 low to moderate immunological risk patients were placed randomly under three study categories of differing immunosuppression regimens consisting of either belatacept with MMF, belatacept with sirolimus and TAC with MMF while they were all on rATG induction with intravenous steroids to 4 days post transplantation.After a 12 months study the biopsy proven AR rate for belatacept/MMF was 14%; for belatacept/sirolimus this fi gure was 4% and for control TAC/MMF this incidence was 3%.Steroid-free immunosuppression may, therefore, not be achieved through CNI-free protocols [61][62][63].

Conclusions
The goal of this evaluation was to provide an up to date evidence of steroid avoidance and withdrawal in kidney transplant recipients for our newly established kidney transplantation unit.Earlier reports from the CsA era on steroid free immunosuppression were adverse due to increased rates of AR, however, this old information is no longer applicable since strategies have been refi ned with more potent medications for induction and maintenance.While the use of steroid free strategies has now been applied extensively, the review has confi rmed total steroid avoidance or very early withdrawal protocols as the most preferred and is considered to be effective by using lymphocyte depleting induction which reduce the immunological risk of graft failure and AR.Most RCTs registered high AR rates in cases where steroids were withdrawn in comparison to where steroids were maintained.
Early AR, however, have no effect on patient and graft survival.
In practice patient selection is most critical for successful outcomes and steroid avoidance is not appropriate for high immunological risk patients, recipients with delayed graft function, prolonged cold ischemia time, cardiac death donation, black patients and those with a history of glomerulonephritis.
Low immunological risk recipients like fi rst transplant cases with low panel reactive antibodies are more appropriate candidates for steroid minimization.The adverse effects of steroids are well documented, however, steroid minimization has been associated with an unclear reduction of these adverse effects.The main argument to be addressed is whether the harmful effects of AR that can be reversed in a small number of patients to maintain the gains associated with steroid avoidance.This review has given an insight on the way forward in choosing a suitable steroid withdrawal protocol for our unit in view of the complexity, unclearness and incompleteness surrounding the issue of steroid avoidance or withdrawal.
It is, therefore, relevant to apply a strategy which utilizes effective induction agents like rATG or alemtuzumab along with intraoperative intravenous steroids, and postoperative maintenance therapy of a low steroid dose tapered at 4 weeks and then further reduced to a very small dose for an indefi nite period in combination with a calcineurin inhibitor TAC and MMF.Transplant recipients with low immunological risk are ideal candidates for early steroid withdrawal.
Pascual et al. in 2009, managed to systematically review all these RCTs to analyze their impact on short and longlived consequences.The steroid sparing techniques had no impact on graft loss or mortality inclusive of death.Patients on conventional steroid therapy had a lower graft loss risk in comparison to those of steroid sparing protocols.There was a high AR rate in the steroid-sparing groups.The frequency of acute rejection was even higher following steroid withdrawal or avoidance than with conventional CsA treatment.As a result of steroid sparing and withdrawal strategies a decrease in the drug requirement for hypertensives, hyperlipidaemia, cholesterol, new onset diabetes after transplantation (NODAT) and cataract.Steroid avoidance managed to reduce cardiovascular episodes.Patients on TAC and CsA had the same antihypertensive and cholesterol reduction need while the need to use medication to treat hyperlipidaemia was prominent with TAC.NODAT reduction for treatment was only noticeable with CsA.Steroid sparing patients on CsA had a reduced infection rate.TAC has been suggested to be more protective than CsA since there was an increased AR rate in the studies utilizing CsA.Patients on steroid avoidance showed less prevalence of NODAT requiring any treatment than those on steroid withdrawal [40].A review by Haller et al., evaluated the benefi t and harms of steroid withdrawal or avoidance for kidney transplant recipients.They reviewed data from 48 RCTs (n= 7803 kidney transplant recipients) of which 3 RCTs (n=346) were children.The review compared steroid withdrawal against steroid maintenance in 24 out of 45 studies in adults, steroid avoidance against steroid maintenance in 18 out of 45 studies in adults, and steroid avoidance against steroid withdrawal in 3 out of 45 studies in adults.Under the steroid withdrawal against steroid maintenance strategy, steroids were withdrawn at 3 months (8 studies), at 6 months (8 studies) at 12 months (1 study) and past 12 months after transplantation (1 study).In the steroid avoidance against steroid maintenance strategy, no steroids were administered before and after the transplantation (2 studies), steroids were withdrawn until day seven after transplantation(12 studies), and between day 8 and 14 (2 studies).Finally in the steroid avoidance against steroid withdrawal strategy (3 studies), there was steroid withdrawal up till the seventh day after transplantation in the avoidance group and steroid withdrawal within 3 and 6 months subsequent to transplantation in the steroid withdrawal group.Patient mortality and graft loss was not signifi cantly different in the steroid withdrawal versus steroid maintenance study and in the steroid avoidance versus steroid maintenance group.The chances of AR were highly increased in recipients who received steroid therapy for less than 14 days following transplantation (fi gure 2) and also in patients who were taken off steroid treatment at a subsequent time after transplantation (fi gure 3).No evidence was established to show any difference in the comparative groups for adverse or harmful events like malignancy and infection.The outcomes were measured within year one up to fi ve years post kidney transplantation.In this review, most of the studies compared steroid withdrawal against steroid maintenance.Pediatric transplantation studies consisted of steroid withdrawal versus steroid maintenance with death, graft loss and rejection.There were limited studies for the comparison of steroid avoidance against steroid withdrawal with death, graft loss and AR (fi gure 4).

Figure 1 :
Figure 1: Incidence of biopsy-proven acute rejection (BPAR) in 852 unselected kidney transplant patients randomized to alemtuzumab induction with lowexposure tacrolimus, low-dose mycophenolic acid and no steroids, or to basiliximab induction with standard tacrolimus, standard mycophenolic acid and standard steroids.HR, hazard ratio; CI, confi dence interval [45].
Vlachopanos et al., proposed giving the recipient intravenous methylprednisolone in three doses of 500, 250 and 250 mg daily during the kidney transplant operation, and postoperatively on day 1 and 2. This is followed by an accelerated reduction of the methylprednisolone to 20mg oral per day for up to 2-4 weeks.Finally, the steroid dose is decreased to achieve 4 mg per day at 3 months and maintained at the same dose if no acute rejection is experienced [7].Maintenance therapy is still commonly practiced in kidney transplant recipients.Woodle et al in the Astellas Corticosteroid Withdrawal Study comprising of 386 patients with Panel reactive antibodies of less than 25%, designed a strategy where one study group had steroids discontinued at 7 days following transplantation and the second group gradually reduced to 5mg per day at 6 months.
Information relating to application of steroid avoidance in patients who are at an increased immunological risk is still scares.Outcomes on the basis of rATG induction with steroid withdrawal at day 4 post transplantation in African Americans maintained on TAC and Sirolimus or MMF have been analysed in two studies by Saull et al., and Haririan et al.For these

Figure 4 :
Figure 4: Comparison of Steroid avoidance versus steroid withdrawal, Outcome -Rejection.Only 3 studies working on this topic were compared.Outcomes were not different between two comparative groups [1].

Table 4 :
[7,54]aclizumab or alemtuzumab induction with steroid avoidance in high-risk or pediatric kidney transplant populations[44].BPAR, biopsy-proven acute rejection; CSA, cyclosporine; DAC, daclizumab; i.v., intravenous; MMF, mycophenolate mofetil; rATG, rabbit antithymocyte globulin; SRL, sirolimus; TAC, tacrolimus.a.At end of study (see study duration in column 3) unless otherwise stated.b.Panel reactive antibodies >20% or retransplantation.c.Signifi cantly improved growth in steroid-free group (mean standard height deviation score −0.9 versus −1.9 [p=0.003]).Body mass index was similar in both groups.d.Signifi cantly improved growth after transplantation (mean standard height deviation score increased from −1.7 to −1.1 [p=0.007]).Body mass index remained stable.Adapted and Modifi ed from Naesens M, Berger S, Biancone L et al.Nefrologia 2016;36(5): 469-480.6 months post transplantation.The survival rates of patients and allograft including graft function were not divergent in the study arms[7,54].Hocker et al., also achieved identical results in a study involving 42 moderate to high risk children on CsA, MMF immunosuppression maintenance and had steroid withdrawal at 12 months post transplantation, please refer to