Two-dose Daclizumab Induction Therapy in 209 Liver Transplants: A Single-Center Analysis

A randomized controlled trial of daclizumab versus anti-thymocyte globulin induction for heart transplantation

Background

The purpose of this study was to test the efficacy and safety of daclizumab (DZM) versus anti-thymocyte globulin (ATG) as a component of induction therapy in heart transplant recipients.

Methods

Thirty heart transplant patients were randomized to receive either ATG or DZM during induction therapy. Patients in the DZM group received an initial dose of 2 mg/kg intravenous (IV) at the time of transplant and 1 mg/kg IV on postoperative day 4.

Discussion

Recipient, donor, and intraoperative variables did not differ significantly between groups. The cost of induction therapy, total drug cost, and hospital ward costs were significantly less for the DZM group. Average absolute lymphocyte and platelet counts were significantly higher in the DZM group. There were no significant differences in the incidence of rejection, infection, malignancy, or steroid-induced diabetes. One year survival was excellent in both groups (87%, P = 0.1). Daclizumab is a safe component of induction therapy in heart transplantation.

Risk of serious opportunistic infections after solid organ transplantation: interleukin-2 receptor antagonists versus polyclonal antibodies. A meta-analysis

BACKGROUND

We aimed to evaluate and quantify the risk of serious opportunistic infections after induction with polyclonal antibodies versus IL-2 receptor antagonists (IL-2RAs) in randomized clinical trials.

METHODS

PRISMA guidelines were followed and random-effects models were performed.

RESULTS

70 randomized clinical trials (10,106 patients) were selected: 36 polyclonal antibodies (n = 3377), and 34 IL-2RAs (n = 6729). Compared to controls, polyclonal antibodies showed higher risk of serious opportunistic infections (OR: 1.93, 95% CI: 1.34-2.80; p < 0.0001); IL-2RAs were associated with lower risk of serious opportunistic infections (OR: 0.80, 95% CI: 0.68-0.94; p = 0.009). Polyclonal antibodies were associated with higher risk of bacterial (OR: 1.58, 95% CI: 1.00-2.50; p = 0.049) and viral infections (OR: 2.37, 95% CI: 1.60-3.49; p < 0.0001), while IL-2RAs were associated with lower risk of cytomegalovirus (CMV) disease (OR: 0.73, 95% CI: 0.56-0.97; p = 0.032). Adjusted indirect comparison: compared to polyclonal antibodies, IL-2RAs were associated with lower risk of serious opportunistic infections (OR: 0.41, 95% CI: 0.34-0.49; p < 0.0001), bacterial infections (OR: 0.51, 95% CI: 0.39-0.67; p < 0.0001) and CMV disease (OR: 0.58, 95% CI: 0.34-0.98; p = 0.043). Results remained consistent across allografts.

CONCLUSION

The risk of serious opportunistic infections, bacterial infections and CMV disease were all significantly decreased with IL-2RAs compared to polyclonal antibodies.

Induction immunosuppression in liver transplantation: a review

Antibody therapy for induction is seldom used in liver transplantation in the United States, but continues to be used in approximately 10% of patients. The most commonly used antibody at the current time is basiliximab (Simulect, Novartis) and is used in adults with renal dysfunction at the time of liver transplantation with the intention of delaying introduction of calcineurin-inhibitors. In children, the same antibody is commonly used in order to reduce rates of acute rejection. Most patients, adult and pediatric, are treated with initially higher levels of tacrolimus rather than antibody induction.

Outcomes and native renal recovery following simultaneous liver-kidney transplantation

With the increase in patients having impaired renal function at liver transplant due to MELD, accurate predictors of posttransplant native renal recovery are needed to select candidates for simultaneous liver-kidney transplantation (SLK). Current UNOS guidelines rely on specific clinical criteria for SLK allocation. To examine these guidelines and other variables predicting nonrecovery, we analyzed 155 SLK recipients, focusing on a subset (n = 78) that had post-SLK native GFR (nGFR) determined by radionuclide renal scans. The 77 patients not having renal scans received a higher number of extended criteria donor organs and had worse posttransplant survival. Of the 78 renal scan patients, 31 met and 47 did not meet pre-SLK UNOS criteria. The UNOS criteria were more predictive than our institutional criteria for all nGFR recovery thresholds (20-40 mL/min), although at the most conservative cut-off (nGFR ≤ 20) it had low sensitivity (55.3%), specificity (75%), PPV (67.6%) and NPV (63.8%) for predicting post-SLK nonrecovery. On multivariate analysis, the only predictor of native renal nonrecovery (nGFR ≤ 20) was abnormal pre-SLK renal imaging (OR 3.85, CI 1.22-12.5). Our data support the need to refine SLK selection utilizing more definitive biomarkers and predictors of native renal recovery than current clinical criteria.

Basiliximab induction and delayed calcineurin inhibitor initiation in liver transplant recipients with renal insufficiency

BACKGROUND

Renal insufficiency (RI) is common after liver transplantation (LT) and may worsen due to calcineurin inhibitor (CNI) use. We compared LT outcomes using basiliximab induction and delayed CNI initiation to controls with a standard CNI regimen in patients with peri-LT RI.

METHODS

All adults transplanted January 2004 to December 2007 with peri-LT RI (hemodialysis or creatinine ≥1.5 within 1 week of LT) were included in a retrospective nonrandomized cohort. Outcomes including 30-day and 1-year patient and graft survival and renal function were compared between basiliximab and control groups.

RESULTS

Two hundred twenty-nine patients (102 basiliximab, 127 controls) were analyzed, mean age 54 years, 72% men, 54% with hepatitis C virus. Mean model for end-stage liver disease (28.2 vs. 20.0; P<0.001) and creatinine (1.9 vs. 1.6; P=0.001) were higher and more patients were on hemodialysis at LT (29% vs. 6%; P<0.001) in the basiliximab group. 30-day patient (99% vs. 97%; P=0.26) and graft survival (98% vs. 95%; P=0.17), 1-year patient (87% vs. 87%; P=0.89) and graft survival (86% vs. 82%; P=0.37), mean creatinine at 1-year (1.5 vs. 1.5 mg/dL; P=0.82), and treated acute rejection (6% vs. 6%; P=0.90) were similar between basiliximab and control groups, respectively. In multivariable logistic regression, basiliximab was not significantly associated with 30-day (odds ratio, 0.10; P=0.11) or 1-year (odds ratio, 0.97; P=0.94) survival, controlling for age, previous LT, model for end-stage liver disease, and hepatitis C virus.

CONCLUSIONS

Basiliximab induction resulted in 30-day and 1-year patient, graft and renal outcomes comparable with a control group receiving standard CNI-based immunosuppression. Antibody induction with delayed CNI should be further studied prospectively.

Immunosuppression with low-dose daclizumab in liver transplant recipients with impaired kidney function: a single-center experience

BACKGROUND

Nephrotoxicity of calcineurin inhibitors (CNI) may exert detrimental effects, particularly in orthotopic liver transplantation (OLT) patients with impaired kidney function. Immunosuppression with daclizumab permits delayed introduction of CNI, and may be preferred for patients with kidney dysfunction. This retrospective analysis of our experience using daclizumab was performed among patients who underwent transplantation with impaired kidney function.

METHODS

We analyzed 168 patients. A serum creatinine (Cr) level >1.5 mg/dL was the indication for a protocol with low-dose daclizumab (50 mg intravenous [IV], day 0 and day 4), mycophenolate mofetil (MMF; 500 mg twice daily IV/orally), and tapering doses of prednisolone from day 0 after OLT. CNI were introduced at day 4-15 after OLT. Patients with a Cr level <1.5 mg/dL received immunosuppression with CNI+MMF+steroids or CNI+steroids.

RESULTS

Fourteen patients fulfilled the criterion for daclizumab immunosupression. Their Cr and creatinine clearance (CrCl) values at OLT were 2.85 +/- 1.22 mg/dL and 19 +/- 11 mL/min, respectively. In the remaining 154 patients, Cr and CrCl results were 0.88 +/- 0.3 mg/dL and 107 +/- 82 mL/min, respectively. At discharge, the daclizumab group showed Cr and CrCl estimates of 0.97 +/- 0.45 mg/dL and 86 +/- 34 mL/min (P < .0001 for both, when compared with prior to OLT). Both Cr and CrCl levels at discharge were not different from those values of patients who underwent transplantation with normal kidney function. The incidence of acuterejection was 14% in the daclizumab group and 18% in the other recipients (P = not significant [NS]).

CONCLUSIONS

Immunosuppression with low-dose daclizumab and delayed introduction of CNI was safe and did not increase the risk of an acute rejection episode, thus offerring an excellent therapeutic option for patients who undergo transplantation with impaired kidney function.

Two-dose daclizumab induction in pediatric renal transplantation

DCZ, an IL-2 receptor antagonist, has been widely used for induction therapy in pediatric and adult solid organ transplantation. Originally, it was recommended as a five-dose regimen; however, fewer doses may be efficacious and less costly for prevention of rejection. There is limited experience with the use of fewer doses in pediatric renal transplantation. We retrospectively reviewed the outcomes of 26 primary pediatric renal transplants performed at a single center between June 2004 and May 2007 receiving induction therapy with two-dose DCZ (1.5 mg/kg preoperatively and day seven post-transplant). Maintenance immunosuppression included tacrolimus, MMF, and prednisone in all patients. Forty-six percent were African American and 92% were deceased-donor transplants. After a mean follow-up of 17.8 +/- 7.5 months, acute rejection was noted in 11.5% and graft survival was 92.3%. CMV infection occurred in 11.5%, but no case of BK nephropathy or post-transplant lymphoproliferative disorder was observed. Our preliminary results suggest that induction therapy with two-dose DCZ was convenient, economical, and effective in preventing rejection episodes without an increase in adverse events or hospital stay. Larger randomized clinical trials with longer duration of follow-up are needed to more fully validate the use of this regimen in pediatric renal transplantation.

Tacrolimus monotherapy in liver transplantation: one-year results of a prospective, randomized, double-blind, placebo-controlled study

BACKGROUND

Minimal immunosuppression (IS) is desirable in organ transplantation to reduce side effects and to promote the process of tolerance induction.

MATERIAL AND METHODS

Between February 2000 and September 2004, 156 adults (>15 years old) receiving a primary liver graft were enrolled in a prospective, randomized, double-blind, placebo-controlled, investigator-driven single-center study comparing tacrolimus (TAC)-placebo (PL) and TAC-low-dose, short-term (64 days) steroid (ST) IS. There were no exclusion criteria at moment of randomization. All patients had a 12-month follow-up (range, 12-84).

RESULTS

Three- and 12-month patient survival rates were 93.6% and 87.2% in the TAC-PL group and 98.7% and 94.7% in TAC-ST group (P = 0.096 and P = 0.093, respectively). Three- and 12-month graft survival rates were 92.3% and 85.9% versus 97.4% and 92.3% (P = 0.14 and 0.13, respectively). By 3 and 12 months, rejection treatment had been given in 20.5% (16 pts) and 23% (18 pts) of TAC-PL patients and in 12.7% (10 pts) and 20.5% (16 pts) of TAC-ST patients (P = 0.20 and 0.54). Corticosteroid-resistant rejection (CRR) at 3 and 12 months was recorded in 12.8% (10 pts) of TAC-PL patients and 3.8% (3 pts) of TAC-ST patients (P = 0.04). When considering the 145 patients transplanted without artificial organ support (n = 145), CRR at 3 and 12 months was recorded in 8.8% (6/68 pts) of TAC-PL patients and in 3.9% (3/77 pts) of TAC-ST patients (P = 0.22). Vanishing bile duct syndrome was diagnosed in 1 (1.2%) TAC-PL patient and 4 (5.1%) TAC-ST patients (P = 0.17). By 1 year, 78.2% (61/78) of TAC-PL patients and 82% (64/78) of TAC-ST patients were on TAC monotherapy (P = 0.54). When considering 67 TAC-PL and 74 TAC-ST survivors, rates of monotherapy were 91% (61 pts) and 86.5% (64 pts) (P = 0.39). At 1 year, 62.5% (42 pts) of TAC-PL survivors and 64.9% (48 pts) of TAC-ST survivors were on low-dosage (<6 ng/mL) TAC monotherapy (P 0.79).

CONCLUSION

TAC monotherapy can be achieved safely without compromising graft nor patient survival in a primary, even unselected, adult liver transplant population. The higher incidence of early CRR in the TAC-PL group related to the significantly higher number of patients transplanted while being on artificial organ support. In such condition, this monodrug immunosuppressive strategy needs to be adapted. TAC monotherapy strategy should lay the basis for further large scale minimization studies in liver transplantation.

Following-up of a four-dose daclizumab induction therapy without calcineurin inhibitors in a liver transplantation recipient with severe renal dysfunction: a case report

BACKGROUND

There is debate on the dose schedule and pharmacokinetics of daclizumab in liver transplant recipients.

METHODS

A four-dose course of daclizumab was administered to a patient with severe renal dysfunction. Calcineurin inhibitor therapy initiation was delayed to 86 days posttransplantation.

RESULTS

The patient is well as 480 days after transplantation. No rejection was observed.

CONCLUSIONS

The result suggested the efficacy of our dose schedule, but it will be necessary to confirm it with further pharmacokinetic studies and more cases.

Calcineurin inhibitor-sparing regimens in solid organ transplantation: focus on improving renal function and nephrotoxicity

BACKGROUND

The calcineurin inhibitors (CNIs), cyclosporine and tacrolimus, have had a revolutionary effect on the overall success of renal transplantation through reduction in early immunologic injury and acute rejection rates. However, the CNIs have a significant adverse impact on renal function and cardiovascular disease, and extended long-term graft survival has not been achieved. The recognition of these effects sparked interest in CNI-sparing strategies. Strategies to limit CNI exposure include CNI minimization, avoidance, and withdrawal. We sought to review the impact of CNI-sparing strategies in kidney, liver, and heart transplantation.

MATERIALS AND METHODS

A PubMed search 1966 to August 2006 was conducted to identify relevant research articles, and the references of these articles as well as the authors' personal files were reviewed.

RESULTS

Calcineurin inhibitor minimization using mycophenolate mofetil or sirolimus may be associated with a modest increase in creatinine clearance (CrCl) and a decrease in serum creatinine (SCr) in the short term. Despite improvement in CrCl or SCr, CNI nephrotoxicity and chronic allograft nephrotoxicity are progressive over time when CNI exposure is maintained. In kidney transplantation, the tubulo-interstitial and glomerular damage are irreversible. Mycophenolate mofetil may improve renal outcomes during CNI minimization more than sirolimus, and antibody induction may be effective to limit CNI exposure, but longer-term follow-up data are required. Use of sirolimus with mycophenolate mofetil or azathioprine to avoid CNI exposure de novo has improved glomerular filtration rate for at least two yr in most studies in kidney transplantation; however, experience is limited in liver and heart transplantation, and reports of delayed graft function and wound healing with sirolimus may have dampened enthusiasm for de novo use. Late CNI withdrawal has achieved variable results, possibly because withdrawal was attempted after the kidney damage was too extensive. Early CNI withdrawal, prior to significant graft damage, has generally improved CrCl and markers of fibrosis and decreased chronic allograft lesions, a finding also observed with sirolimus in most CNI avoidance studies. Successful withdrawal appears to be more effective than CNI minimization.

CONCLUSIONS

Calcineurin inhibitors are associated with significant nephrotoxicity and chronic kidney damage. Minimization is associated with a modest increase in renal function, but persistent damage is observed on biopsies as long as the CNIs are continued. Avoidance is hampered by lack of experience and possible sirolimus-induced side effects. CNI withdrawal may be the best option by delivering CNIs during the early period of immunologic graft injury and then converting them to less nephrotoxic agents before significant renal damage occurs.

Preserving renal function in liver transplant recipients with rabbit anti-thymocyte globulin and delayed initiation of calcineurin inhibitors

Early renal dysfunction following liver transplantation is associated with increased morbidity and mortality. To evaluate the impact of delayed initiation of calcineurin inhibitor on renal function, we conducted a retrospective study comparing 118 liver transplant recipients who received rabbit anti-thymocyte globulin and delayed initiation of calcineurin inhibitor with 80 liver transplant recipients who received no antibody and early initiation of calcineurin inhibitor (control group). All patients received mycophenolate mofetil and steroids. Delayed calcineurin inhibitor initiation with anti-thymocyte globulin was associated with significant improvement in renal function throughout the first year post-transplant. At 12 months post-transplant, patients treated with this regimen experienced lower serum creatinine (1.4 +/- 0.5 versus 1.7 +/- 0.5 mg/dL, P < 0.001), a higher estimated glomerular filtration rate (57.4 +/- 20.5 versus 43.7 +/- 14.4 mL/min/1.73 m(2), P < 0.001), and less dependence on dialysis (0.8% versus 13%, P < 0.001) in comparison with no antibody and early calcineurin inhibitor initiation. Patient survival and graft survival were similar between groups; however, there was a trend of a lower incidence of early biopsy-proven acute rejection with anti-thymocyte globulin. Overall infection and cytomegalovirus infection were significantly lower in anti-thymocyte globulin-treated patients, and there was no increased incidence of hepatitis C recurrence in comparison with controls. In conclusion, delayed initiation of calcineurin inhibitor with anti-thymocyte globulin in liver transplant recipients is safe and is associated with improvements in renal function and a lower incidence of early acute rejection in comparison with no antibody and early initiation of calcineurin inhibitor.

Daclizumab

Daclizumab is a humanized monoclonal antibody which binds to the IL-2 receptor on activated lymphocytes and blocks the production of IL-2. Its use is well established in solid organ transplantation as induction therapy, especially in high-risk patients where reduction or delayed dose of standard immunosuppression would be beneficial. It has been used effectively in both 2-dose and 5-dose regimens in conjunction with other standard immunosuppressive agents. The incidence of acute rejection appears reduced without increasing the rates of infection or post-transplant lympho-proliferative disorders. The agent is generally well tolerated in adults and children and there is no need for additional monitoring. Daclizumab has also been used outside the transplant arena in a variety of immune-mediated diseases with limited success.

Avoiding calcineurin inhibitors in the early post-operative course in high-risk liver transplant recipients: The role of extracorporeal photopheresis

The aim of this work is to report on the results of a single-center, prospective study on the feasibility of calcineurin-inhibitor (CNI)-staggered immunosuppression by use of extracorporeal photopheresis (ECP) in liver transplant (LT) recipients at risk of renal and neurological complications. Patients were matched on a 1:1 basis with historical controls on standard CNI immunosuppression. ECP patients were treated with ECP plus antimetabolites and/or steroids, while CNIs were withheld until clinically indicated. Thirty-six patients were evaluated: 18 ECP patients and 18 controls. ECP was tolerated in 100% of cases. CNI were introduced at a median of 8 days (4-55) in 17 ECP patients, while one patient was on a fully CNI-sparing regimen 22 months after LT. Acute rejection occurred in 27.7% patients in ECP (5/18) versus 16.7% in controls (3/18) (P = ns) with a shorter time to rejection in ECP (36 +/- 31.3 days vs. 83.6 +/- 65.6 days; P = ns). All rejection episodes were amenable to medical treatment. Neurological and renal complications occurred in 22.2% (4/18) of patients in either group, but led to in-hospital mortality in 3 patients among controls versus 1 in ECP (P = ns). One-, 6-, and 12-month survival rates were 94.4, 88.1, and 88.1% in ECP versus 94.4, 77.7, and 72.2% among controls (P < 0.0001). ECP seems to allow for management of high-risk LT recipients in the early post-transplant course and reduction of CNI-related mortality. Continued data validation is favored to assess the impact of ECP on long-term graft and patient survival.

Two-dose basiliximab compared with two-dose daclizumab in renal transplantation: a clinical study

BACKGROUND

Addition of the interleukin-2 receptor (IL-2R) antagonists basiliximab or daclizumab to a calcineurin inhibitor-based regimen significantly reduces risk of acute rejection with a tolerability profile similar to a placebo. Use of a truncated two-dose regimen of daclizumab has been reported, but till date, there has been no controlled study of two-dose daclizumab vs. two-dose basiliximab.

METHODS

Deceased-donor renal transplant recipients were randomized to basiliximab (20 mg on days 0 and 4) or daclizumab (50 mg on days 1 and 14) with cyclosporine, mycophenolate mofetil and corticosteroids. Flow cytometry was used to calculate the proportion of CD25(+) T cells in peripheral blood.

RESULTS

Thirty patients were randomized to basiliximab and 28 to daclizumab. There was one patient death in each group, with no other graft losses. By six months, the incidence of biopsy-proven acute rejection was 0% with basiliximab vs. 21.4% with daclizumab (p < 0.05). Three patients in the daclizumab group required OKT3 for steroid-resistant rejection. There were no between-group differences in the incidence of infection. The proportion of CD25(+) T cells declined markedly during the first two wk in both groups, but was significantly lower in the basiliximab group during weeks six to eight.

CONCLUSION

Two doses of basiliximab are more effective than two 1 mg/kg doses of daclizumab in preventing acute rejection in de novo renal transplant patients receiving cyclosporine, mycophenolate mofetil and corticosteroid maintenance therapy. In patients receiving relatively low-level immunosuppression in order to minimize toxicity, basiliximab may be preferable to a truncated daclizumab regimen.

Daclizumab induction and maintenance steroid-free immunosuppression with mycophenolate mofetil and tacrolimus to prevent acute rejection of hepatic allografts

Steroid-free immunosuppressive regimens reduce corticosteroid-related side effects in liver transplant recipients although their efficacy is very variable. We evaluated the efficacy and safety of a steroid-free regimen in a 6-month, open-label, multicenter, pilot study, which involved 102 liver transplant patients treated with daclizumab (2 mg/kg within 6 h following transplant and 1 mg/kg on day 7), mycophenolate mofetil (MMF, 1 g b.i.d) and tacrolimus (trough levels of 5-15 ng/ml in the first month and 5-10 ng/ml thereafter). One intra-operative dose of methylprednisolone was administered. At 6 months, the acute rejection rate was 9.8%, and patient and graft survival rates were 96% and 95%, respectively. Acute rejection rates were similar for hepatitis C-positive patients (8.6%) and hepatitis C-negative patients (10.4%). Infections occurred in 22% of patients; most cases were considered mild or moderate. Post-transplantation hypertension and diabetes mellitus developed in 37% and 14% of patients, respectively, during the study period, but were markedly less frequent (8% and 6%, respectively) at 6 months. Hypercholesterolemia was observed in only 2% of patients. In conclusion, the steroid-free immunosuppressive regimen of daclizumab, MMF, and tacrolimus effectively prevents acute rejection after liver transplantation without decreasing safety.

Five-year follow-up after clinical islet transplantation

Islet transplantation can restore endogenous beta-cell function to subjects with type 1 diabetes. Sixty-five patients received an islet transplant in Edmonton as of 1 November 2004. Their mean age was 42.9 +/- 1.2 years, their mean duration of diabetes was 27.1 +/- 1.3 years, and 57% were women. The main indication was problematic hypoglycemia. Forty-four patients completed the islet transplant as defined by insulin independence, and three further patients received >16,000 islet equivalents (IE)/kg but remained on insulin and are deemed complete. Those who became insulin independent received a total of 799,912 +/- 30,220 IE (11,910 +/- 469 IE/kg). Five subjects became insulin independent after one transplant. Fifty-two patients had two transplants, and 11 subjects had three transplants. In the completed patients, 5-year follow-up reveals that the majority ( approximately 80%) have C-peptide present post-islet transplant, but only a minority ( approximately 10%) maintain insulin independence. The median duration of insulin independence was 15 months (interquartile range 6.2-25.5). The HbA(1c) (A1C) level was well controlled in those off insulin (6.4% [6.1-6.7]) and in those back on insulin but C-peptide positive (6.7% [5.9-7.5]) and higher in those who lost all graft function (9.0% [6.7-9.3]) (P < 0.05). Those who resumed insulin therapy did not appear more insulin resistant compared with those off insulin and required half their pretransplant daily dose of insulin but had a lower increment of C-peptide to a standard meal challenge (0.44 +/- 0.06 vs. 0.76 +/- 0.06 nmol/l, P < 0.001). The Hypoglycemic score and lability index both improved significantly posttransplant. In the 128 procedures performed, bleeding occurred in 15 and branch portal vein thrombosis in 5 subjects. Complications of immunosuppressive therapy included mouth ulcers, diarrhea, anemia, and ovarian cysts. Of the 47 completed patients, 4 required retinal laser photocoagulation or vitrectomy and 5 patients with microalbuminuria developed macroproteinuria. The need for multiple antihypertensive medications increased from 6% pretransplant to 42% posttransplant, while the use of statin therapy increased from 23 to 83% posttransplant. There was no change in the neurothesiometer scores pre- versus posttransplant. In conclusion, islet transplantation can relieve glucose instability and problems with hypoglycemia. C-peptide secretion was maintained in the majority of subjects for up to 5 years, although most reverted to using some insulin. The results, though promising, still point to the need for further progress in the availability of transplantable islets, improving islet engraftment, preserving islet function, and reducing toxic immunosuppression.