Kaija Salmela

Islet Surface Heparinization Prevents the Instant Blood-Mediated Inflammatory Reaction in Islet Transplantation

OBJECTIVE—In clinical islet transplantation, the instant blood-mediated inflammatory reaction (IBMIR) is a major factor contributing to the poor initial engraftment of the islets. This reaction is triggered by tissue factor and monocyte chemoattractant protein (MCP)-1, expressed by the transplanted pancreatic islets when the islets come in contact with blood in the portal vein. All currently identified systemic inhibitors of the IBMIR are associated with a significantly increased risk of bleeding or other side effects. To avoid systemic treatment, the aim of the present study was to render the islet graft blood biocompatible by applying a continuous heparin coating to the islet surface. RESEARCH DESIGN AND METHODS—A biotin/avidin technique was used to conjugate preformed heparin complexes to the surface of pancreatic islets. This endothelial-like coating was achieved by conjugating barely 40 IU heparin per full-size clinical islet transplant. RESULTS—Both in an in vitro loop model and in an allogeneic porcine model of clinical islet transplantation, this heparin coating provided protection against the IBMIR. Culturing heparinized islets for 24 h did not affect insulin release after glucose challenge, and heparin-coated islets cured diabetic mice in a manner similar to untreated islets. CONCLUSIONS—This novel pretreatment procedure prevents intraportal thrombosis and efficiently inhibits the IBMIR without increasing the bleeding risk and, unlike other pretreatment procedures (e.g., gene therapy), without inducing acute or chronic toxicity in the islets.

A randomized multicenter trial of the anti-ICAM-1 monoclonal antibody (enlimomab) for the prevention of acute rejection and delayed onset of graft function in cadaveric renal transplantation: a report of the European Anti-ICAM-1 Renal Transplant Study Group.

BACKGROUND T-cell activation through T-cell receptor engagement requires co-stimulatory molecules and also adhesion molecules such as ICAM-1. Moreover ICAM-1 mediates leukocyte invasion from the blood into tissue during inflammatory processes. In animal studies using mouse monoclonal antibodies against ICAM-1 (enlimomab), renal allograft survival has been improved and reperfusion damage from ischemia reduced. The European Anti-ICAM-1 Renal Transplant Study (EARTS) was a randomized, double-blind, parallel-group, placebo-controlled study lastingl year and performed in 10 transplant centers in Europe. METHODS A total of 262 recipients of cadaveric kidneys were given either enlimomab or a placebo for 6 days and were given triple immunosuppressive therapy of cyclosporine, azathioprine, and prednisolone. The primary efficacy endpoint was the incidence of the first acute rejection within 3 months, and each event was assessed by a committee including investigators and independent pathologists. RESULTS There was no significant difference in the incidences of first acute rejection at 3 months between the placebo and enlimomab groups (39% vs. 45%), and enlimomab did not reduce the risk of delayed onset of graft function (DGF) (26% vs. 31%). Neither was there a difference in patient survival (95% vs. 91%) or graft survival (89% vs. 84%) at 1 year. Fatal events occurred in 19 (7%) patients (7 placebo, 12 enlimomab). Clinically, the most important non-fatal adverse events were infections; however, there was no statistically significant difference between the incidences in the two groups (70% vs. 79%). CONCLUSION Short term enlimomab induction therapy after renal transplantation did not reduce the rate of acute rejection or DGF.

A randomized, double-blind trial of basiliximab immunoprophylaxis plus triple therapy in kidney transplant recipients

BACKGROUND A double-blind, placebo-controlled, randomized study was performed to assess whether immunoprophylaxis with basiliximab (Simulect) could reduce the incidence of acute rejection in kidney transplant recipients treated with cyclosporine (Neoral), steroids, and azathioprine. METHODS Three hundred forty patients received either placebo or basiliximab at a dose of 20 mg, given intravenously on days 0 and 4. All patients received cyclosporine, steroids, and azathioprine. The primary endpoint was the incidence of acute rejection at 6 months. Secondary endpoints included the safety and tolerability of basiliximab and placebo, 1-year patient and graft survival, and significant medical events up to 12 months. RESULTS During the first 6 months posttransplantation, acute rejection occurred in 20.8% of patients given basiliximab versus 34.9% of patients administered placebo (P=0.005). Similarly, there was a reduction in biopsy-proven acute rejection at 6 months in the patients receiving basiliximab (P=0.023). One-year patient survival was 97.6% with basiliximab and 97.1% with placebo, graft survival was 91.5% versus 88.4%, respectively (NS). The adverse-events profile of patients treated with basiliximab was indistinguishable from that of patients treated with placebo. The number of patients with infections was similar (65.5% for basiliximab vs. 65.7% for placebo), including cytomegalovirus infections (17.3% vs. 14.5%, P=0.245). Nine neoplasms (three in the basiliximab group, six in the placebo arm) were recorded up to 1 year from transplantation. CONCLUSIONS Basiliximab in combination with cyclosporine, steroids, and azathioprine triple therapy was highly effective in reducing the incidence of acute renal allograft rejection without increasing the incidence of infections and other side effects.

Optimising islet engraftment is critical for successful clinical islet transplantation

Clinical islet transplantation is currently being explored as a treatment for persons with type 1 diabetes and hypoglycaemia unawareness. Although ‘proof-of-principle’ has been established in recent clinical studies, the procedure suffers from low efficacy. At the time of transplantation, the isolated islets are allowed to embolise the liver after injection in the portal vein, a procedure that is unique in the area of transplantation. A novel view on the engraftment of intraportally transplanted islets is presented that could explain the low efficacy of the procedure.

Minimization of Immunosuppressive Therapy After Renal Transplantation: Results of a Randomized Controlled Trial

Modern immunosuppressive regimens reduce the acute rejection rate by combining a cornerstone immunosuppressant like tacrolimus or cyclosporine with adjunctive agents like corticosteroids, mycophenolate mofetil (MMF) or azathioprine, often associated with untoward side effects.

Two corticosteroid-free regimens-tacrolimus monotherapy after basiliximab administration and tacrolimus/mycophenolate mofetil-in comparison with a standard triple regimen in renal transplantation : results of the Atlas study.

Background. The side effects associated with corticosteroids have led to efforts to minimize their use in renal transplant patients. In this study we compared two corticosteroid-free tacrolimus-based regimens with a standard triple therapy. Methods. This was a 6-month, phase III, open-label, parallel-group, multicenter study. The total analysis set comprised 451 patients, randomized (1:1:1) to receive tacrolimus (Tac) monotherapy following basiliximab (Bas) administration (n=153), Tac/mycophenolate mofetil (MMF) (n=151), or, Tac/MMF/corticosteroids triple therapy as a control (n=147). Results. The study was completed by 91.2% (triple therapy), 94.7% (Tac/MMF), and 82.4% (Bas/Tac) of patients. Patient baseline characteristics were similar in all groups. The incidences of biopsy-proven acute rejection were 8.2% (triple therapy), 30.5% (Tac/MMF), and 26.1% (Bas/Tac), p<0.001 (multiple test for comparison with triple therapy); Bas/Tac vs. Tac/MMF, p=ns. The incidences of corticosteroid-resistant acute rejection were 2.0%, 4.0%, and 5.2%, p=ns. Graft survival (95.9%, 96.7%, and 94.7%, p=ns) and patient survival (100%, 99.3%, and 99.3%, p=ns) were similar in all groups. Median serum creatinine at month 6 was 123.0 &mgr;mol/L (triple therapy), 134.7 &mgr;mol/L (Tac/MMF) and 135.8 &mgr;mol/L (Bas/Tac). The overall safety profiles were similar; differences (p<0.05) were reported for anaemia (24.5% vs. 12.6% vs. 14.5%), diarrhoea (12.9% vs. 17.9% vs. 5.9%), and leukopenia (7.5% vs. 18.5% vs. 5.9%) for the triple therapy, Tac/MMF, and Bas/Tac group, respectively. The incidences of new-onset diabetes mellitus were 4.6%, 7.1%, and 1.4%, respectively. Conclusion. Corticosteroid-free immunosuppression was feasible with the Bas/Tac and the Tac/MMF regimens. Both corticosteroid-free regimens were equally effective in preventing acute rejection, with the Bas/Tac therapy offering some safety benefits.

Urine neutrophil gelatinase-associated lipocalin is a marker of graft recovery after kidney transplantation

Delayed graft function (DGF), especially long-lasting DGF, complicates kidney transplant outcome. Neutrophil gelatinase-associated lipocalin (NGAL) is an acute kidney injury marker; therefore, we tested whether urine NGAL could predict DGF, prolonged DGF (lasting over 14 days), or the quality of kidney function in transplant recipients without DGF (non-DGF). We collected urine samples from 176 recipients transplanted with deceased donor kidneys before and various days after transplantation. A total of 70 transplantations had DGF, of which 26 were prolonged. Patients who developed DGF had a significantly slower decrease in urinary NGAL compared with those without DGF, such that day 1 NGAL predicted DGF (area under the curve (AUC) 0.75) and predicted DGF in 15 of 112 cases with day 1 urine output over 1 l (AUC 0.70) and in 19 of 86 cases with a day 1 decrease in creatinine over 50 μmol/l (AUC 0.74). The urinary NGAL level on day 1 predicted prolonged DGF (AUC 0.75), which had significantly worse 1-year graft survival (73%), compared with shorter DGF (100%). In non-DGF, high day 3 NGAL (greater than the mean) was associated with significantly worse kidney function at 3 weeks compared with low NGAL, but not at 3 months and 1 year. NGAL did not correlate with long-term function in DGF. Hence, day 1 urinary NGAL predicted DGF even when it was not clinically expected early on, and importantly, it predicted prolonged DGF that led to worse graft survival.

Persistent cytomegalovirus infection in kidney allografts is associated with inferior graft function and survival

The long‐term effects of cytomegalovirus (CMV) infections on kidney allografts are unknown. We examined the impact of persistent intragraft CMV infection on long‐term kidney allograft function and survival. CMV was diagnosed in 82/172 renal transplant recipients by antigenemia test and viral cultures. Biopsies from 48 of 82 patients taken after CMV infection and from 15 patients with no previous CMV infection detected were available for the immunohistochemical demonstration of CMV antigens and DNA hybridization in situ. Five‐year follow‐up data from these 63 patients were analysed. In 17 patients, CMV antigens and/or DNA persisted in the biopsy >2 months after the last positive finding in blood or urine. Patients with persistent intragraft CMV had reduced graft survival (P = 0.041) and Cox regression analysis showed persistent CMV as a risk factor for reduced graft survival (RR: 3.5). Recipients with persistent intragraft CMV had reduced creatinine clearance 1 and 2 years after transplantation (P = 0.007) and in multivariate logistic regression analyses including several potential pre‐ and posttransplant risk factors, persistent CMV was an independent risk factor for lower clearance at 1 and 2 years (OR: 4.4 and 4.9). Our novel findings show that persistent intragraft CMV infection was associated with reduced kidney allograft function and survival.

Cytokine Gene Polymorphisms and Risks of Acute Rejection and Delayed Graft Function after Kidney Transplantation

Background. Pretransplantation identification of patients at an increased risk for adverse events would allow more individualized treatment strategies possibly improving long-term outcome. We studied cytokine gene polymorphisms of kidney allograft recipients and their donors to identify factors predisposing for acute rejection (AR) and delayed graft function (DGF). Methods. A total of 291 adult cadaver kidney recipients transplanted at a single transplantation centre between 1999 and 2002 were investigated. Recipients and donors were typed for TNF-&agr;(-308G/A), TGF-&bgr;1(codon 10T/C, codon 25C/G), IL-10(-1082G/A, -819C/T, -592C/A), IL-6(-174C/G), and IFN-&ggr;(+874T/A) polymorphisms using a SSP-PCR kit. An AR episode was defined based on clinical and histological findings (Banff criteria). Results. The incidence of AR was 17%. In univariate statistical analyses recipients with TNF-&agr; -308AA-genotype were found to be at a significantly increased risk for rejection (odds ratio [OR] 5.0, 95% CI 3.0–8.3, P=0.003). The association was independent from the patient-donor HLA-mismatch status. In addition, patients with IL-10 ACCACC, ATAATA, GCCATA (-1082A/G, -819C/T, -592C/A, respectively) haplotypes were predisposed to rejection (OR 1.9, 95% CI 1.1–3.1, P=0.016). Further, the combination of recipient TGF-&bgr;1 25GG-genotype and donor IL-10 -819T-allele was associated with rejection (OR 1.8, 95% CI 1.1–3.0, P=0.027). These variables remained significant risk factors also in a multivariate logistic regression analysis. The incidence of DGF was 22%. The risk was increased by a donor TNF-&agr; -308GA-genotype (OR 1.6, 95% CI 1.1–2.6, P=0.040). Conclusions. Our results confirm that cytokine gene polymorphisms influence the outcome of kidney transplantation. Our data especially identify the TNF-&agr; -308AA-genotype as a factor predisposing for AR episodes.

Time Course of Serum Prolactin and Sex Hormones following Successful Renal Transplantation

Background: Chronic renal failure is commonly associated with disturbances in hypothalamic-pituitary-gonadal function. Methods: The gonadotrophins, prolactin and estradiol or testosterone levels were measured immediately before renal transplantation, at discharge from the transplantation unit (19 ± 8 days after Tx) and 6 months after transplantation in 21 patients, 7 females and 14 males, age range 21–60 years. Results: The mean prolactin level was high during uremia and decreased rapidly after transplantation, from 441 to 167 mU/l in males and from 1,057 to 521 mU/l in females. Hypergonadotrophism was seen in most uremic patients, with the mean LH and FSH levels of 14.2 and 6.0 U/l in males and 14.7 and 4.0 U/l in females, respectively. A temporary change to hypogonadotrophic hypogonadism took place 2–3 weeks after transplantation and was followed by normalization of the hypothalamic-gonadal function. The levels of circulating sex steroids were suppressed when the patients were discharged from the transplantation unit but returned to the normal range at 6 months. Conclusions: We conclude that renal transplantation corrects the hyperprolactinemia induced by uremia and is followed by rapid onset of restoration of the hypothalamic-pituitary-gonadal axis.