Dimitri Mikhalski

Cold ischemia is a major determinant of acute rejection and renal graft survival in the modern era of immunosuppression.

Background. The aim of our study was to examine, in a recent cohort of kidney transplant recipients who have received modern immunosuppressive therapy, the respective role of cold ischemia time (CIT) and delayed graft function (DGF) on acute rejection (AR) rates and long-term graft survival. Methods. We retrospectively reviewed the charts of 611 renal transplantations between 1996 and 2005. Most patients received a calcineurin inhibitor as maintenance therapy, either cyclosporine (43%) or tacrolimus (52%) and 76% of the patients received an antilymphocyte induction therapy. Study endpoints were DGF, first-year AR, and long-term graft survival. Uni- and multivariate analyses were performed to determine factors that may have influenced the study outcomes. Results. DGF was observed in 16.2% of patients. Both older donor age and longer CIT were significant risk factors for DGF. DGF rates were similar whether patients received a calcineurin inhibitor before transplantation or not. AR occurred in 16.5% of grafts during the first year. Independent predictors of AR by multivariate analysis were duration of dialysis, CIT, current panel-reactive lymphocytotoxic antibody more than 5%, and the number of human leukocyte antigen-A, B, and DR mismatches. Each hour of cold ischemia increases the risk of rejection by 4%. With respect to death-censored graft survival, three pretransplant parameters emerged as independent predictors of graft loss: younger recipient age, peak panel-reactive lymphocytotoxic antibody more than 5% and longer CIT. The detrimental effect of CIT on graft survival was entirely because of its propensity to trigger AR. When AR was added to the multivariate Cox model, CIT was no longer significant whereas first-year AR became the most important predictor of graft loss (Hazards ratio, 4.6). Conclusion. Shortening CIT will help to decrease not only DGF rates but also AR incidence and hence graft loss. Patients with prolonged CIT should receive adequate immunosuppression, possibly with antilymphocyte preparations, to prevent AR occurrence.

Conversion From Prograf to Advagraf Among Kidney Transplant Recipients Results in Sustained Decrease in Tacrolimus Exposure

Background. Advagraf is a slow release form of tacrolimus with once-daily formulation. The potential advantages of Advagraf are better adherence and a safer profile by avoiding toxic peak concentrations. In this study, we evaluated the required daily doses of tacrolimus and subsequent blood levels on conversion from Prograf to Advagraf among kidney transplant recipients. Methods. We retrospectively reviewed data from 55 patients for whom a switch from Prograf to Advagraf was identified. Tacrolimus daily doses and concomitant blood levels were analyzed at several time points ranging from 3 months before to 6 months after conversion. Results. We observed a significant increase in tacrolimus daily doses, starting with a dose of 0.063 mg/kg of Prograf, increasing up to 0.081 mg/kg of Advagraf at 6 months (P<0.0001). After conversion, we observed a quick and sustained decrease in trough tacrolimus levels, decreasing from 8.05 ng/mL at day 0 to 6.30 ng/mL at day 180 (P=0.0009). At 6 months, 35% of patients experienced a decrease in trough levels of more than 30%. Creatinine values remained stable over time, and no patient experienced an acute rejection episode. Conclusions. Contrary to the manufacturer instructions, we found a significant decrease in tacrolimus exposure after switching to Advagraf. Therefore, the switch from Prograf to Advagraf should be performed under close medical supervision.

HLA mismatches remain risk factors for acute kidney allograft rejection in patients receiving quadruple immunosuppression with anti-interleukin-2 receptor antibodies.

Background. New immunosuppressive drugs such as anti-interleukin-2 receptor antibodies (aIL2R) and mycophenolate mofetil (MMF) have reduced the incidence of acute rejection after renal transplantation. Whether matching donor and recipient human leukocyte antigen (HLA) antigens is still relevant in patients receiving modern immunosuppression has been questioned. Methods. We retrospectively analyzed the incidence and risk factors of acute rejection during the first posttransplant year and the impact of acute rejection on long-term graft survival in a cohort of 208 renal transplant patients treated with aIL2R (basiliximab, n=166; daclizumab, n=42), calcineurin inhibitors (tacrolimus, n=180; cyclosporin, n=28), mycophenolate mofetil, and steroids. Graft and patient survival were calculated by the Kaplan-Meier method. Risk factors for acute rejection were analyzed by logistic regression modeling. Results. Twenty-seven patients were treated for acute rejection (26 biopsy-proven) during the first posttransplant year. The Kaplan-Meier estimate of first-year acute rejection was 13.2%. The number of HLA mismatches (odds ratio [OR] 1.65 per HLA mismatch) and long periods of dialysis before transplantation (OR 3.1 for more than 4 years of dialysis) were the only independent risk factors for first-year acute rejection. First-year acute rejection was associated with a significant reduction in overall and death-censored graft survival at 5 years after transplantation. Conclusions. Although infrequent in patients receiving modern immunosuppressive drugs, acute rejection remains an important risk factor for graft loss after renal transplantation. Our results suggest that better HLA matching and shorter periods of dialysis before transplantation could reduce acute rejection rates and further improve outcomes under current immunosuppressive regimens.

Thrombophilic Factors Do Not Predict Outcomes in Renal Transplant Recipients Under Prophylactic Acetylsalicylic Acid

A cohort of recipients of renal transplant after 2000 (N = 310) was prospectively screened on the day of transplantation and 1 month later for a panel of 11 thrombophilic factors to assess their effect on posttransplant outcomes. All patients received prophylactic acetylsalicylic acid, started before transplantation.

A New HLA Allocation Procedure of Kidneys From Deceased Donors in the Current Era of Immunosuppression

INTRODUCTION It has recently been proposed to replace the current Eurotransplant kidney allocation based primarily on mismatches (MM) at the 3 HLA loci by a simpler system based on full HLA-DR compatibility. The present study analyzes this system in the current era of immunosuppression. METHODS From 1999 to 2012, 723 renal grafts were performed on 586 patients who were treated with a calcineurin inhibitor, mycophenolate mofetil, and in most cases antilymphocyte globulins. Four groups of HLA MM were compared: (A) A+B 2-4/DR 1-2 MM (n = 397), (B) A+B 2-4 MM/DR 0 MM (n = 106), (C) A+B 0-1 MM/DR 1-2 MM (n = 138), and (D) A+B 0-1/DR 0 MM (n = 82). RESULTS Acute rejection episodes were less frequent during the first post-transplantation year in group D than in the other groups (P = .018). Patient survival was lower in group A than in the other groups (P = .008). Immunologic graft survival was higher in group D than in the other groups in univariate (P = .015) and multivariate analyses (P = .033; 96.4% vs 90.1% at 10 years). CONCLUSIONS In the current era of immunosuppression, allocation of kidneys from deceased donors could be performed primarily according to full DR compatibility then to the best A+B matching, affording excellent graft outcome to most recipients.

Ineligibility for renal transplantation: prevalence, causes and survival in a consecutive cohort of 445 patients.

Kianda MN, Wissing KM, Broeders NE, Lemy A, Ghisdal L, Hoang AD, Mikhalski D, Donckier V, Vereerstraeten P, Abramowicz D. Ineligibility for renal transplantation: prevalence, causes and survival in a consecutive cohort of 445 patients.
Clin Transplant 2011: 25: 576–583.

Patient and graft outcome in current era of immunosuppression: a single centre pilot study

Abstract Objectives: The present single centre study aims at analyzing the impact on renal allograft outcome of the important changes which occurred in the transplant population and immunosuppressive therapy during the last two decades. Methods: From 2000 to 2013, 779 single kidney transplantations were performed on 635 patients who all received on an intent-to-treat basis steroids, a calcineurin inhibitor, mycophenolate mofetil and an induction therapy with either antithymocyte globulin or an antagonist directed to the interleukin (IL)-2 receptor. Uni- and multivariate analyses of patient and immunologic graft survival were conducted. Results: The sole factor predicting patient survival is recipient’s age: 10-year survival rates are 94·7, 81·6 and 57·9% for the <45, 45–60 and >60 years age groups, respectively (P<0·001). Peak (>50% panel reactive antibodies) anti-human leucocyte antigens (HLA) sensitization, cold ischaemia time and HLA-B and -DR mismatches (MM) influence graft outcome: at 10 years, the difference in 10-year survival rates is 5·9% between grafts from sensitized and not sensitized patients (90·9 vs 96·8%, P = 0·002), 3·8% between grafts with <18 and ≧18 hours cold ischaemia (96·6 vs 92·8%, P = 0·003), 7·3% between grafts with no MM and either B or DR MM versus those with B and DR MM (96·8 vs 89·5%, P = 0·002). Conclusion: In our single centre experience, graft survival was most strongly determined by HLA matching, offering excellent long term graft outcome to most patients.

Ticlopidine and clopidogrel, sometimes combined with aspirin, only minimally increase the surgical risk in renal transplantation: a case–control study

BACKGROUND Patients undergoing kidney transplantation are sometimes being treated with antiplatelet agents such as ticlopidine or clopidogrel. Some teams refuse to wait-list these patients for fear of bleeding during transplant surgery. METHODS We retrospectively reviewed the records of 702 adult patients with a kidney transplant alone between 2000 and 2010. Nineteen (2.7%) patients were taking clopidogrel or ticlopidine when called in for transplantation. Furthermore, 10 of these 19 patients were also taking low-dose aspirin (ASA). We compared the risk of bleeding peri- and postoperatively, and the occurrence of cardiovascular complications within 30 days after renal transplantation between 19 cases and 39 controls randomly selected within the cohort. RESULTS Platelets were administered to 7 cases (37%) versus 0 controls (P<0.001). A single case (5.3%) presented with significant bleeding during surgery following an implantation biopsy, and required 4 red bood cell (RBC) units. During the first day, 3 of the 19 cases (16%) and 1 of the 39 controls required RBC (P=0.1). No reoperation was performed for bleeding. After the transplant, clopidogrel or ticlopidine was resumed in only two patients. The platelet count and haemoglobin were similar between cases and controls at Day 30. No cardiovascular event occurred in cases or controls during the first month post-transplantation. At 5 years, graft and patient survival was similar in cases and controls. CONCLUSIONS Clopidogrel and ticlopidine, sometimes in combination with ASA, are associated with a low risk of bleeding during renal transplantation and does not seem to be a contraindication for renal transplant surgery.

Shipping donor kidneys within Eurotransplant: outcomes after renal transplantation in a single-centre cohort study.

BACKGROUND Shipment of organs during the allocation process aims to improve human leucocyte antigen (HLA) matching but can also have a detrimental effect by prolonging cold ischaemia. The overall effect of organ exchange on post-transplant outcomes in the Eurotransplant (ET) region has not been investigated. METHODS This is a retrospective single-centre cohort study to investigate the effect of shipment of renal allografts on cold ischaemia times and the incidence of acute rejection (AR) and graft survival in 661 transplantations of deceased donor kidneys. RESULTS Forty-six per cent (N = 301) of the patients received a locally procured and 54% (N = 360) a shipped donor kidney. Locally procured donors tended to be older, more often hypertensive and had less frequently died from trauma. Recipients of shipped kidneys were at higher immunological risk, being younger, more frequently retransplanted and immunized against HLA antigens. Shipped kidneys had a 2.2-h prolongation of cold ischaemia time (18.0 versus 20.2 h; P < 0.0001) but significantly less HLA A, B and DR mismatches (2.20 versus 2.84; P < 0.0001). Recipients of shipped kidneys had an increased incidence of first-year AR [19 versus 13%; odds ratio 1.62 (1.06-2.49); P = 0.026] and death-censored graft loss [hazard ratio 1.6 (1.1-2.4); P = 0.01] that was no longer statistically significant after adjustments for risk factors by multivariable modelling. CONCLUSIONS Shipment of kidneys in the ET region is associated with a modest increase in cold ischaemia time and significantly better HLA matching. This allows for successful transplantation of higher risk patients with no significant penalty with regard to AR rates or death-censored graft survival.

Outcomes of kidney transplantations in children weighing 15 kilograms or less: a retrospective cohort study

Kidney transplantation (KT) is often delayed in small children because of fear of postoperative complications. We report early‐ and long‐term outcomes in children transplanted at ≤15 kg in the two largest Belgian pediatric transplant centers. Outcomes before (period 1) and since the introduction of basiliximab and mycophenolate‐mofetil in 2000 (period 2) were compared. Seventy‐two KTs were realized between 1978 and 2016: 38 in period 1 and 34 in period 2. Organs came from deceased donors in 48 (67%) cases. Surgical complications occurred in 25 KTs (35%) with no significant difference between the two periods. At least one acute rejection (AR) occurred in 24 (33%) KTs with significantly less patients experiencing AR during period 2: 53% and 12% in period 1 and, period 2 respectively (P < 0.001). Graft survival free of AR improved significantly in period 2 compared with period 1: 97% vs. 50% at 1 year; 87% vs. 50% at 10 years post‐KT (P = 0.003). Graft survival tended to increase over time (period 1: 74% and 63% at 1 and 5 years; period 2: 94% and 86% at 1 and 5 years; P = 0.07), as well as patient survival. Kidney transplantation in children ≤15 kg remains a challenging procedure with 35% of surgical complications. However, outcomes improved and are nowadays excellent in terms of prevention of AR, patient and graft survival.