Steroid withdrawal in pancreas transplant recipients

Minimization of steroids in liver transplantation

Because of the markedly improved short-term results of liver transplantation (LT) and persistently high number of long-term complications, the attention of transplant physicians should be focused on minimizing immunosuppressive therapy as much as possible. Steroid-based immunosuppression is responsible for a substantial post-LT morbidity and mortality, hence, minimization of its use is of utmost importance to improve the quality of life of the successfully transplanted liver recipient. This literature review shows that LT can be performed safely with steroid-minimal immunosuppression without compromising graft and patient survival. The tendency in clinical practice is to move more and more from steroid withdrawal to steroid avoidance protocols.

Minimization and withdrawal of steroids in pancreas and islet transplantation

For reducing the corticosteroid (CS)-related side-effects, especially cardiovascular events, CS-sparing protocols have become increasingly common in pancreas transplantation (PT). Lympho-depleting induction antibodies, such as rabbit anti-thymocyte globulin (rATG) or alemtuzumab, have been widely used in successful trials. The results of various CS-sparing protocols combining calcineurin inhibitors (CNI) and mycophenolate or sirolimus, have been mixed for rejection and survival rates. Most of the studies were uncontrolled trials of low-risk patients, therefore the grade of evidence is limited. Large-scale prospective studies with long-term follow up are necessary to assess risks and benefits of CS-sparing regimens in PT before recommending such strategies as standard practice. Islet allo-transplantation for patients with brittle type 1 diabetes mellitus, less invasive and safer procedure than PT, has been attempted since late 1980s, but diabetogenic immunosuppressants at maintenance, mainly CS and high-dose CNI, prevented satisfactory results (10% insulin-independence at 1-year post-transplant). Since 2000, CS-free and CNI-reducing protocols, including more potent induction [daclizumab, OKT3gamma1(ala-ala) anti-CD3 antibody, rATG] and maintenance (sirolimus, mycophenolate) agents, have significantly improved short-term outcomes whereas long-term are still inadequate (from 80% to 20% insulin-independence from 1- to 5-year post-transplant). Main limitations are allo- and autoimmunity, immunosuppression-related islet and systemic toxicity and transplant site unsuitability, which tolerogenic protocols and biotechnological solutions may solve.

Early steroid withdrawal in solitary pancreas transplantation results in equivalent graft and patient survival compared with maintenance steroid therapy

Although steroid withdrawal in simultaneous kidney pancreas transplantation has been shown to be feasible, the results of early steroid withdrawal in immunologically solitary pancreas transplantation are not well known. This study evaluated an early steroid withdrawal protocol in this group. The results of steroid withdrawal at 21 d post-transplant in solitary pancreas transplant recipients was compared with a control group consisting of solitary pancreas transplant recipients maintained on steroids (MG). Additional immunosuppression consisted of rabbit anti-thymocyte globulin induction followed by tacrolimus and mycophenolate mofetil in both groups. The withdrawal group (WG, n = 22) consisted of 11 pancreas transplant alone (PTA), six pancreas after kidney (PAK), and five simultaneous cadaveric pancreas living kidney (SPLK) recipients. The steroid maintenance group (MG, n = 32) consisted of 8 PTA, 11 PAK, and 13 SPLK recipients. Recipient and donor demographic characteristics were similar. Seventy eight percent of MG patients had infection-related complications in the first year compared with 50% of the WG patients (p = 0.04). The one-yr rejection, pancreas graft, and patient survival rates were 27.3% 95.5%, and 100% in the WG, and 37.5%, 81.3%, and 93.8% in the MG respectively and not significantly different. We conclude that early corticosteroid withdrawal in isolated pancreas transplantation results in fewer infections and can be achieved without an increased risk of rejection or graft loss over the first year.

Successful steroid withdrawal in lung transplant recipients: result of a pilot study

OBJECTIVE

Corticosteroids play a key role in immunosuppression after transplantation. However, because chronic steroid treatment may cause significant morbidity and mortality, steroid-free immunosuppression remains a desirable goal. To the best of our knowledge, there are no reports on successful steroid withdrawal (SW) in lung transplant recipients.

METHODS

The study group included 35 patients who underwent heart-lung, double-lung or single-lung transplantation. Criteria for initiation of SW were stable pulmonary function tests and absence of clinical or bronchoscopic evidence of acute or chronic rejection in the last 6 months. Pulmonary function, blood pressure and metabolic parameters were compared between the patients who underwent SW and those who did not.

RESULTS

Eight patients (23%) underwent SW. Median follow-up was 19 months (range 11-23 months). Compared to the non-withdrawal group, the withdrawal group was older (60+/-6 vs. 52+/-13 years, P=0.01, r=0.49), had higher rates of emphysema (88% vs. 18%, P=0.01) and use of a cyclosporine-based regimen (62% vs. 26%, P=0.0001), and had longer time from transplantation to the withdrawal attempt (70+/-13 vs. 29+/-26 months, P=0.0002). The SW group showed no adverse effects in graft function and no deterioration on pulmonary function tests. SW had a beneficial metabolic effect, with a decrease in mean cholesterol level from 229+/-45 to 194+/-25 mg/dl (P=0.02) and no significant change in weight, systolic blood pressure or glucose level. In the non-withdrawal group, mean cholesterol levels increased from 175+/-34 to 209+/-57 mg/dl (P=0.0005), weight increased from 72+/-15 to 80+/-14 kg (P=0.0001), and systolic blood pressure increased from 125+/-15 to 139+/-16 mmHg (P=0.001); glucose levels did not change. There was a significant correlation between total cholesterol level and weight in both groups (P=0.0006, r=-0.56 and P=0.01, r=-0.46, respectively).

CONCLUSIONS

Late SW is safe in stable patients after lung transplantation. There was no evidence of rejection or a deterioration in pulmonary function. Lipid profile improvement and blood pressure stabilization accompanied the termination of steroid therapy.

Tailored immunosuppression and steroid withdrawal in pancreas-kidney transplantation

BACKGROUND

Recent improvements in simultaneous pancreas-kidney transplantation (SPK) and the striking decrease in acute rejection lead us to focus on the effects of long-term immunosuppression.

AIM OF THIS STUDY

Evaluation of a policy of steroid withdrawal and tailored immunosuppression in pancreas-kidney patients treated in a single center.

METHODS

review of the clinical charts in 9 SPK recipients (male/female = 5/4, median age 41 years, median follow-up 42 months), by the same operator, under supervision of the two usual caregivers. Therapeutic protocols. Induction phase: all patients received mycophenolate mophetil (starting dose: 2 grams), tacrolimus and steroids, 8 received Simulect, 1 received thymoglobulins. Maintenance therapy was slowly reduced, with the goal of steroid withdrawal.

RESULTS

The therapeutic adjustments were mainly determined by two almost opposing elements: 1. Rapid adjustments in the case of side-effects (gastrointestinal problems, infections and neoplasia); 2. Slow tapering off in the case of good organ function. On the other hand, a switch to cyclosporine A and to rapamycine was considered in the case of chronic organ malfunction. By these means, over a median of 42 months follow-up, steroid withdrawal was slowly obtained in 6/9 patients (at a median time of 25 months).

CONCLUSIONS

Within the limits of this small-scale study, a tailored immunosuppressive policy allows at least some "positively selected" patients to reach the "dream" of steroid withdrawal after SPK.

New immunosuppressive drugs: an update

An increasing number of immunosuppressive drugs became available for clinical use over the past few decades. These include substances with recently recognized immunosuppressive properties, which needed careful evaluation in various trials before they could be approved for use in different diseases. The effectiveness of other agents was already established, but knowledge about their modes of action or the mechanisms that lead to side effects was acquired much later. This understanding also contributed to the development of new drugs that display synergistic effects or lack certain adverse effects. The greater choice afforded by such research endeavours allows us to select the best therapeutic strategy for an individual patient; however, this requires a comprehensive knowledge of the available options. The present review provides an update of current knowledge of the most important substances (including calcineurin and target of rapamycin inhibitors, regulators of gene expression, and inhibitors of purine and pyrimidine synthesis) and surveys some of the novel agents that are expected to play an important role in the future.

Current treatment practice in immunosuppression

New drugs have recently been added that may eventually replace the two-decade dominance of cyclosporin in solid organ transplantation. This cornerstone of immunosuppression was introduced by Borel [1] and Calne [2] in the mid-70s. In 1989, Starzl et al., after 2 years of preclinical experimentation, introduced tacrolimus (originally designated as FK506 by the Fujisawa Pharmaceutical Company of Japan) as a potent immunosuppressant for liver transplants [3]. Also, in recent years, a variety of novel purine and pyrimidine biosynthesis inhibitors have been tested for transplantation therapy. The leading agent which appears to be replacing the 35-year position occupied by azathioprine is the semi-synthetic morpholinoethyl ester of mycophenolic acid (MPA), mycophenolate mofetil (MMF), introduced by Allison [4] and Sollinger [5], and developed by the Syntex Corporation (now Roche Pharmaceuticals). Others, affecting different intra- or intercellular messages amplifying immunity, are in the pipeline.