Influence of number of retransplants on renal graft outcome

Predictors of graft function and survival in second kidney transplantation: A single center experience

BACKGROUND

The increasing kidney retransplantation rate has created a parallel field of research, including the risk factors and outcomes of this advanced form of renal replacement therapy. The presentation of experiences from different kidney transplantation centers may help enrich the literature on kidney retransplantation, as a specific topic in the field of kidney transplantation.

AIM

To identify the risk factors affecting primary graft function and graft survival rates after second kidney transplantation (SKT).

METHODS

The records of SKT cases performed between January 1977 and December 2014 at a European tertiary-level kidney transplantation center were retrospectively reviewed and analyzed. Beside the descriptive characteristics, the survivals of patients and both the first and second grafts were described using Kaplan-Meier curves. In addition, Kaplan-Meier analyses were also used to estimate the survival probabilities at 1, 3, 5, and 10 post-operative years, as well as at the longest follow-up duration available. Moreover, bivariate associations between various predictors and the categorical outcomes were assessed, using the suitable biostatistical tests, according to the predictor type.

RESULTS

Out of 1861 cases of kidney transplantation, only 48 cases with SKT were eligible for studying, including 33 men and 15 women with a mean age of 42.1 ± 13 years. The primary non-function (PNF) graft occurred in five patients (10.4%). In bivariate analyses, a high body mass index (P = 0.009) and first graft loss due to acute rejection (P = 0.025) were the only significant predictors of PNF graft. The second graft survival was reduced by delayed graft function in the first (P = 0.008) and second (P < 0.001) grafts. However, the effect of acute rejection within the first year after the first transplant did not reach the threshold of significance (P = 0.053). The mean follow-up period was 59.8 ± 48.6 mo. Censored graft/patient survival rates at 1, 3, 5 and 10 years were 90.5%/97.9%, 79.9%/95.6%, 73.7%/91.9%, and 51.6%/83.0%, respectively.

CONCLUSION

Non-immediate recovery modes of the first and second graft functions were significantly associated with unfavorable second graft survival rates. Patient and graft survival rates of SKT were similar to those of the first kidney transplantation.

Iterative renal transplantation: our experience on third transplants

PURPOSE

To report our experience on third kidney transplantation, analyzing the complications and graft survival rates as compared to previous transplants.

METHODS

Retrospective study of third renal transplants performed at our center. Outcomes were compared with a cohort of first and second transplants.

RESULTS

Of a total of 4143, we performed 72 third transplants in 46 men and 26 women with an average age of 46 years and mean time on dialysis of 70 months. Thirty-seven patients were hypersensitized [panel-reactive antibody (PRA) > 50%]. They were all from deceased donors, with a mean cold ischemia time of 19.2 h. The extraperitoneal heterotopic approach was used in 88.8%, transplantectomy was performed in 80.6% and vascular anastomoses were realized mostly to external iliac vessels, using the common iliac artery in 15 cases, and the inferior vena cava in 16. The main ureteral reimplantation technique was the Politano-Leadbetter (76.4%). Third transplantation reported a significantly higher incidence of lymphocele (13.9% vs. 3.2% in first and 4.5% in second transplants; p < 0.001), rejection (34.7% vs. 14.9% and 20.5%, p < 0.001) and urinary obstruction (11.1% vs. 3.6% and 6.3%, p 0.002). Graft survival rates for first, second and third transplants were 87%, 86% and 78% at 1 year, 83%, 82% and 74% at 3 years and 80%, 79% and 65% at 5 years, respectively.

CONCLUSION

Iterative transplantation constitutes a valid therapeutic option with adequate surgical and survival results compared to previous transplants. It is a challenging procedure which must be performed by experienced surgeons.

Eplet-based virtual PRA increases transplant probability in highly-sensitized patients

BACKGROUND

The reduced access of highly-sensitized (HS) patients to kidney transplantation (KTx) is one of the major challenges for transplant community. Therefore, the aim of our study was to estimate the impact of three different vPRA calculations, assessed traditionally and using eplet-based analysis, in donor offers.

METHODS

At 01-01-2020, 157 HS patients are waitlisted for deceased donor KTx and were included in this study. Total vPRA (vPRAt) was calculated considering all patient allosensitization history, using 1 k MFI cut-off. Current vPRA (vPRAc) refers only to the last year SAB assays, using 1 k MFI cut-off. For eplet vPRA (vPRAe) every SAB assay was analyzed by HLAMatchmaker and HLAfusion software. Matching runs have been performed taking vPRA calculation as unacceptable antigens (UAs).

RESULTS

All patients had at least one previous sensitizing event and patients with 100% vPRA were predominantly candidates for retransplantation (P < 0.001), had higher PRA-CDC (P < 0.001), and longer dialysis vintage waiting time (P < 0.001). Inter-group movement analysis between vPRA measures showed that 70 (45%), 124 (79%) and 80 (51%) patients were reclassified to a lower group when considering vPRAt to vPRAc, vPRAt to vPRAe and vPRAc to vPRAe, respectively. The median percentage of change in estimated number of match runs needed for 95% probability of finding an acceptable donor was significantly more pronounced by increasing vPRAt intervals, when considering the reclassification from vPRAt to vPRAe (P < 0.001) or vPRAc to vPRAe (P = 0.045), while from vPRAt to vPRAc it was not (P = 0.899).

CONCLUSIONS

Our study demonstrated that the use of total or current vPRA calculations are impairing HS patients, by decreasing transplant probability, leading to dramatically longer waiting times, when compared to eplet based vPRA.

The management of lower limb arteriovenous grafts in the perioperative period following renal transplantation

BACKGROUND

The presence of a lower limb arteriovenous graft (LL-AVG) is indicative of a group of complex hemodialysis patients who have precarious long-term vascular access. The aim of this study is to describe our experience of the clinical decisions and interactions between LL-AVG and renal transplantation.

METHODS

The records of 23 patients who received a transplant in the presence of a LL-AVG between 2010 and 2018 were analyzed: firstly, to determine whether patients with a LL-AVG received extended criteria transplants, the implantation procedure, and the management of the LL-AVG in the post-operative period.

RESULTS

Seventeen patients (74%) had "end-stage access" and were thus considered for all offer stratified by the kidney donor profile index (KDPI) and donor type (DBD or DCD). In eleven patients (48%), a kidney with a high risk of delayed graft function was transplanted. Same-sided renal transplantation occurred in only 35% of cases, and of these, only one LL-AVG was ligated immediately to improve transplant perfusion.

CONCLUSION

A patient-based approach applied in decision-making on management of the LL-AVG post-transplantation should include (a) the likelihood of delayed graft function, (b) the need for post-operative hemodialysis, (c) the side of proposed transplant compared to the LL-AVG, and (d) local complications.

Clinical Prognosis of Renal Retransplant Patients: A Single-Center Experience

BACKGROUND

Retransplantation is a treatment option in patients with end-stage renal failure due to graft loss. Outcomes of these patients due to high immunologic risk remain unclear. The aim of this study was to evaluate outcomes of renal retransplantation patients retrospectively.

METHODS

Renal retransplant patients in our unit were evaluated retrospectively between 2010 and 2018. Patients' demographic characteristics, primary diseases, the causes of prior graft loss, immunologic status, desensitization protocols, the induction and maintenance treatments, the complications during the follow-up period, numbers of acute rejections, and the clinical prognosis were all detected from the patients' files.

RESULTS

We retrospectively evaluated 17 patients who underwent a second or third renal allograft. Of these, 16 received a second and the remaining 1 patient received a third renal allograft. Immunologically, all of the 17 patients had negative flow cytometry crossmatch, 1 patient had a positive complement-dependent cytotoxicity crossmatch (Auto 12%), 16 patients had positive panel reactive antibody, the median HLA-mismatch was 3.5, and the score of donor-specific antibody relative intensity score (RIS) was 6.4 ± 6.3. Ten pretransplant patients had desensitization treatment. While scores for HLA-MM and HLA-RIS in the patients who had a desensitization therapy were determined higher, no statistical difference was observed (respectively, P = .28 and .55). No acute rejection episode developed. BK virus DNA viremia was detected in 4 patients during the posttransplant 6th month. We observed no patient death or no graft loss during the follow-up period.

CONCLUSION

Although the retransplant patients who had a graft loss previously have high immunologic risks, retransplantation is reliable in these patients, but they should be followed up carefully in terms of BKV nephropathy.

Surgical Safety and Efficacy of Third Kidney Transplantation in the Ipsilateral Iliac Fossa

BACKGROUND Kidney re-transplantation is a relevant option for patients who are returning to dialysis after graft failure. However, evidence is lacking to what extend a third kidney transplantation in the ipsilateral iliac fossa is safe and effective. The aim of this study was to investigate the outcomes of third kidney transplantations in the ipsilateral iliac fossa compared to first and second ipsilateral fossa kidney transplantations. MATERIAL AND METHODS There were 2074 kidneys transplanted at the Erasmus MC Rotterdam and at the University Medical Centre Groningen. Donor, recipient, and surgical data were collected. The cohort was divided into 3 groups: recipients of a first graft (I KTx; n=1744), recipients of a second graft (II KTx; n=44), and recipients of a third graft (III KTx; n=7). RESULTS Recipients from the II KTx group had a significantly higher rate of primary non-function (PNF) compared to recipients in the I KTx group and recipients in the III KTx group (4.5% versus 0.7% and 0% respectively; P=0.006). The 1-year graft survival did not differ between groups: 96% for I KTx, 91% for II KTx, and 85% for III KTx (P=0.214). The 5-year graft survival did differ significantly between groups: 89% for I KTx, 82% for II KTx, and 68% for III KTx (P=0.029). There were no differences regards hospital stay and rate of complications between groups. CONCLUSIONS Third kidney transplantation in the ipsilateral iliac fossa is feasible and viable. Short-term results are comparable to the first and the second kidney transplantation, however, long-term results are inferior but acceptable compared to dialysis.

Retransplant Outcomes Compared With First Kidney Transplants: Important Observations Not Reported in the Scientific Registry of Transplant Recipients Annual Report

OBJECTIVES

Twice per year, the Scientific Registry of Transplant Recipients provides risk-adjusted center-specific reports of 1- and 3-year outcomes. In addition, the Registry reports 10-year aggregate survival outcomes for kidney transplant recipients. However, in this annual report, no distinction is made between outcomes of patients with a first transplant versus those with retransplants.

MATERIALS AND METHODS

We analyzed data from the Scientific Registry of Transplant Recipients between 1992 and 2015 to determine outcomes after a 1st, 2nd, or ≥ 3rd kidney transplant. Recipients were stratified by donor source (living vs deceased) and transplant number, and rates of graft failure, death-censored graft failure, and death with functioning graft were determined.

RESULTS

From 1992 to 2015, rates of graft failure and death-censored graft failure at 6 months, 1 year, 3 years, 5 years, and 10 years decreased; however, long-term rates of death with functioning graft were unchanged. Outcomes for 1st and 2nd kidney transplant were better than outcomes for ≥ 3rd transplant.

CONCLUSIONS

It would be extremely valuable if the Scientific Registry of Transplant Recipients could present stratified analyses that would account for a host of factors, including organ sequence, which tend to vary by center. The presentation of risk-adjusted outcomes in the annual Registry report could include a more comprehensive assessment of program performance. Such information would be extremely useful for transplant centers, patients, and their support networks, organ procurement organizations, and other transplant stakeholders.

Survival of Kidney Retransplant Compared With First Kidney Transplant: A Report From Southern Iran

OBJECTIVES

Kidney retransplant is increasingly performed, but patient survival is controversial. The aim of this study was to evaluate the outcomes of patients with second kidney grafts and compare survival rates of recipients with first and second kidney transplant procedures.

MATERIALS AND METHODS

This was a retrospective study analyzing records from the Shiraz University of Medical Sciences transplant ward. Survival rates of retrans?lanted patients were compared with a randomly selected group of first kidney recipients. Factors related to retransplant survival were evaluated. Data were analyzed by SPSS version 16.0, and P < .05 was consi?ered as significant.

RESULTS

This study included 200 patients with first kidney transplants and 68 patients with kidney retransplants. We found that 1-, 3-, 5-, and 7-year graft survival rates were 91.9%, 87.2% ,86.3%, and 86.3% among retransplanted patients versus 98.3%, 95.4%, 90.2%, and 88.7% among the first transplant group (P = .130). Hospital stay duration after transplant, kidney rejection rate during hospitalization, delayed graft function, and creatinine levels at discharge were significantly associated with survival in retransplanted patients (P < .05).

CONCLUSIONS

Kidney retransplants can yield desirable outcomes and is the treatment of choice in patients who have lost their graft. Careful screening for risk factors should be consider for obtaining better results in second kidney transplant procedures.

Re-transplants compared to primary kidney transplants recipients: a mate kidney paired analysis of the OPTN/UNOS database

Outcomes of kidney re-transplant recipients (RTR) were compared to primary recipients (FTR) from paired donor kidneys. Organ Procurement and Transplantation Network (OPTN) database was used to identify deceased donors (n = 6266) who donated one kidney to an RTR and the mate kidney to an FTR between January 2000 to December 2010. As compared to FTR, RTR were younger (45 vs. 52 yr, p < 0.001) and had higher proportion of plasma reactive antibody >80 (25% vs 7%, p < 0.001). There were higher 0 mismatches in RTR (19% vs. 16%, p < 0.001). There were more pre-emptive transplants in RTR (24% vs. 21%, p = 0.002). Delayed graft function (28% vs. 25%, p = 0.007) was higher in RTR. Patient survival was similar in FTR and RTR groups at one, three, and five yr (95.7%, 90.2%, and 82.5% vs. 95.2%, 89.8% and 82.7%). Allograft survival rates were higher in FTR group compared to RTR group at one, three, and five yr (91.1%, 82.4%, and 70.9% vs. 87.8%, 77.4%, and 66.1% p < 0.001). Death-censored allograft survival rates were higher in FTR group at one, three, and five yr (91.3%, 82.7% and 71.4% vs. 88%, 77.7% and 66.5% p < 0.001). In today's era of modern immunosuppression, graft survival in RTR has improved but remains inferior to FTR when controlling for donor factors.

The inferior impact of antibody-mediated rejection on the clinical outcome of kidney allografts that develop de novo thrombotic microangiopathy

BACKGROUND

Antibody-mediated rejection (AMR) can induce and develop thrombotic microangiopathy (TMA) in renal allografts. A definitive AMR (dAMR) co-presents three diagnostic features. A suspicious AMR (sAMR) is designated when one of the three features is missing.

METHODS

Thirty-two TMA cases overlapping with AMR (AMR+ TMA) were studied, which involved 14 cases of sAMR+ TMA and 18 cases of dAMR+ TMA. Thirty TMA cases free of AMR features (AMR- TMA) were enrolled as control group.

RESULTS

The ratio of complete response to treatment was similar between AMR- TMA and AMR+ TMA group (23.3% vs. 12.5%, p = 0.33), or between sAMR+ TMA and dAMR+ TMA group (14.3% vs. 11.1%, p = 0.79). At eight yr post-transplantation, the death-censored graft survival (DCGS) rate of AMR- TMA group was 62.8%, which was significantly higher than 28.0% of AMR+ TMA group (p = 0.01), but similar between sAMR+ TMA and dAMR+ TMA group (30.0% vs. 26.7%, p = 0.92). Overall, the intimal arteritis and the broad HLA (Human leukocyte antigens) mismatches were closely associated with over time renal allograft failure.

CONCLUSION

The AMR+ TMA has inferior long-term graft survival, but grafts with sAMR+ TMA or dAMR+ TMA have similar characteristics and clinical courses.

Semiparametric methods to contrast gap time survival functions: Application to repeat kidney transplantation

Times between successive events (i.e., gap times) are of great importance in survival analysis. Although many methods exist for estimating covariate effects on gap times, very few existing methods allow for comparisons between gap times themselves. Motivated by the comparison of primary and repeat transplantation, our interest is specifically in contrasting the gap time survival functions and their integration (restricted mean gap time). Two major challenges in gap time analysis are non-identifiability of the marginal distributions and the existence of dependent censoring (for all but the first gap time). We use Cox regression to estimate the (conditional) survival distributions of each gap time (given the previous gap times). Combining fitted survival functions based on those models, along with multiple imputation applied to censored gap times, we then contrast the first and second gap times with respect to average survival and restricted mean lifetime. Large-sample properties are derived, with simulation studies carried out to evaluate finite-sample performance. We apply the proposed methods to kidney transplant data obtained from a national organ transplant registry. Mean 10-year graft survival of the primary transplant is significantly greater than that of the repeat transplant, by 3.9 months (p=0.023), a result that may lack clinical importance.

Long-term outcome on kidney retransplantation: a review of 100 cases from a single center

Renal transplantation has become an effective form of treatment for end-stage renal failure. Unfortunately, as a consequence of immunological and nonimmunological pathogenic mechanisms, chronic allograft nephropathy is responsible for the loss of a large proportion of kidney grafts after several years and return to dialysis. We have reported herein our 24 years of experience with second kidney transplantations. Of 1,302 kidney transplantations between January 1983 and June 2007 performed in our transplantation center, 100 were second transplantations. Kidney retransplantation was performed in 74 men and 26 women of overall mean age of 35.4 +/- 12.6 years. Cadaveric donor grafts were transplanted in 92 patients, whereas the remaining 8 were living-related donor kidneys. At 1, 5, and 10 years after kidney transplantation, patient survival rates were 100%, 96%, and 92%, respectively, whereas graft survival rates were 85%, 72%, and 53%, respectively. Immunosuppressive therapy included induction therapy with polyclonal anti-lymphocyte antibodies (ALG/ATG) or (starting from 1999) monoclonal anti CD 25 antibody. Our results demonstrated good outcomes for kidney retransplantations with allocation based on anti- HLA antibody identification together with induction immunosuppression.

The Kidney Transplant Morbidity Index (KTMI): A Simple Prognostic Tool to Help Determine Outcome Risk in Kidney Transplant Candidates

Background

The Kidney Transplant Morbidity Index (KTMI) is a novel prognostic morbidity index to help determine the impact that pretransplant comorbid conditions have on transplant outcome.

Objective

To use national data to validate the KTMI.

Design

Retrospective analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing database.

Setting and Participants

The study sample consisted of 100 261 adult patients who received a kidney transplant between 2000 and 2008.

Main Outcome Measure

Kaplan-Meier survival curves were used to demonstrate 3-year graft and patient survival for each KTMI score. Cox proportional hazards regression models were created to determine hazards for 3-year graft failure and patient mortality for each KTMI score.

Results

A sequential decrease in graft survival (0 = 91.2%, 1 = 88.2%, 2 = 85.4%, 3 = 81.7%, 4 = 77.8%, 5 = 74.0%, 6 = 69.8%, and ≥7 = 68.7) and patient survival (0 = 98.2%, 1 = 96.6%, 2 = 93.7%, 3 = 89.7%, 4 = 84.8%, 5 = 80.8%, 6 = 76.0%, and ≥7 = 74.7%) is seen as KTMI scores increase. The differences in graft and patient survival between KTMI scores are all significant ( P < .001) except between 6 and ≥7. Multivariate regression analysis reveals that KTMI is an independent predictor of higher graft failure and patient mortality rates and that risk increases as KTMI scores increase.

Conclusion

The KTMI strongly predicts graft and patient survival by using pretransplant comorbid conditions; therefore, this easy-to-use tool can aid in determining outcome risk and transplant candidacy before listing, particularly in candidates with multiple comorbid conditions.

Risk-adjusted analysis of relevant outcome drivers for patients after more than two kidney transplants

Renal transplantation is the treatment of choice for patients suffering end-stage renal disease, but as the long-term renal allograft survival is limited, most transplant recipients will face graft loss and will be considered for a retransplantation. The goal of this study was to evaluate the patient and graft survival of the 61 renal transplant recipients after second or subsequent renal transplantation, transplanted in our institution between 1990 and 2010, and to identify risk factors related to inferior outcomes. Actuarial patient survival was 98.3%, 94.8%, and 88.2% after one, three, and five years, respectively. Actuarial graft survival was 86.8%, 80%, and 78.1% after one, three, and five years, respectively. Risk-adjusted analysis revealed that only age at the time of last transplantation had a significant influence on patient survival, whereas graft survival was influenced by multiple immunological and surgical factors, such as the number of HLA mismatches, the type of immunosuppression, the number of surgical complications, need of reoperation, primary graft nonfunction, and acute rejection episodes. In conclusion, third and subsequent renal transplantation constitute a valid therapeutic option, but inferior outcomes should be expected among elderly patients, hyperimmunized recipients, and recipients with multiple operations at the site of last renal transplantation.

Genetically modified porcine split-thickness skin grafts as an alternative to allograft for provision of temporary wound coverage: preliminary characterization

Temporary coverage of severely burned patients with cadaver allograft skin represents an important component of burn care, but is limited by availability and cost. Porcine skin shares many physical properties with human skin, but is susceptible to hyperacute rejection due to preformed antibodies to α-1,3-galactose (Gal), a carbohydrate on all porcine cells. Our preliminary studies have suggested that skin grafts from α-1,3-galactosyltransferase knock out (GalT-KO) miniature swine might provide temporary wound coverage comparable to allografts, since GalT-KO swine lack this carbohydrate. To further evaluate this possibility, eight non-human primates received primary autologous, allogeneic, GalT-KO, and GalT+xenogeneic skin grafts. Additionally, secondary grafts were placed to assess whether sensitization would affect the rejection time course of identical-type grafts. We demonstrate that both GalT-KO xenografts and allografts provide temporary coverage of partial- and full-thickness wounds for up to 11 days. In contrast, GalT+xenografts displayed hyperacute rejection, with no signs of vascularization and rapid avulsion from wounds. Furthermore, secondary GalT-KO transplants failed to vascularize, demonstrating that primary graft rejection sensitizes the recipient. We conclude that GalT-KO xenografts may provide temporary coverage of wounds for a duration equivalent to allografts, and thus, could serve as a readily available alternative treatment of severe burns.

Risk factors for retransplant kidney recipients: relisting and outcomes from patients' primary transplant

As of November 2013, 14.5% of the waitlist for a donor kidney comprised patients awaiting a retransplant. We performed a retrospective cohort study of 11,698 adult solitary kidney recipients using national Scientific Registry of Transplant Recipients data transplanted between 2002 and 2011. The aim was to investigate whether outcomes from patients' initial transplants are significant risk factors for patients' repeat transplants or for likelihood of relisting after a failed primary transplant. Retransplant recipients were more likely to be treated for acute rejection [adjusted odds ratio (AOR), 95% confidence interval (CI) = 1.26 (1.07-1.48), p = 0.0053] or hospitalized (AOR = 1.19, 95% CI 1.08-1.31, p = 0.0005) within a year of retransplantation if these outcomes were experienced within a year of primary transplant. Delayed graft function following primary transplants was associated with 35% increased likelihood of recurrence (AOR = 1.35, 95% CI = 1.18-1.54, p < 0.0001). An increase in 1-year GFR after primary transplant was associated with GFR 1 year postretransplant (β = 6.82, p < 0.0001), and retransplant graft failure was inversely associated with 1-year primary transplant GFR (adjusted hazard ratio = 0.74, 95% CI = 0.71-0.76 per 10 mL/min/1.73 m(2) ). A decreased likelihood for relisting was associated with hospitalization and higher GFR following primary transplantation. The increasing numbers of individuals requiring retransplants highlights the importance of incorporating prior transplant outcomes data to better inform relisting decisions and prognosticating retransplant outcomes.

Long-term outcome of kidney retransplantation in comparison with first kidney transplantation: a report from the Thai Transplantation Registry

INTRODUCTION

Kidney retransplantation is a high-risk procedure that is increasingly performed because of previous graft failure. The aim of this study was to determine the long-term outcomes of kidney retransplantations compared with first kidney transplantations under the current era of immunosuppression.

METHODS

Since the first retransplantation in Thailand was performed in 1993, this study included all consecutive cases registered in the Thai Transplantation Registry database from January 1993 to December 2011. A total of 3337 kidney transplantations were available for the analysis. Graft loss was defined as a return to dialysis or graft removal. Death with a functioning graft was censored.

RESULTS

Of 3337 kidney transplantations during the study period, 113 were second and 3 were third transplantations. Among these 116 retransplantations, the most common identified causes of end-stage renal disease were chronic glomerulonephritis (38.8%), followed by hypertensive nephropathy (13.0%), diabetic nephropathy (6.0%), and lupus nephritis (1.7%). The retransplantation recipients were older (mean age, 46.2 ± 12.8 years) than the first transplantation group (mean age, 42.2 ± 12.8 years). The proportion of living-related kidney transplantations and male sex were similar between first and retransplantation recipients. Fourteen percent of retransplantation recipients showed high immunologic risk as defined by current panel reactive antibodies ≥30% compared with 3% of those in the first transplantation group (P < .001). The percentages of induction therapy with antithymocyte globulin and anti-interleukin-2 antibody in the retransplantation and first transplantation groups were 18.3% versus 4.3% and 60.0% versus 32.6%, respectively. The graft survival rates (95% confidence interval [CI]) at 1, 5, and 10 years were 88.6% (80.7-93.3), 87.3% (79.1-92.5), and 74.4% (53.7-86.9) among retransplantation, versus 95.0% (94.1-95.7), 87.0% (85.5-88.5), and 70.7% (67.4-73.8) among first transplantation groups, respectively (P = .63). Patient survival rates were not different between first and retransplantation groups (P = .42). The leading cause of graft loss in the retransplantation group was chronic allograft nephropathy (22%), whereas infection (57%) was the major cause of death in this group.

CONCLUSION

The 10-year patient and graft survival rates of kidney retransplantation were acceptable. The combination of induction therapy with a calcineurin inhibitor and a mycophenolate mofetil/mychophenolic acid-based regimen lead to outcomes comparable to first kidney transplantations among our cohort of 3337 patients.

Predicting the outcome of renal transplantation

OBJECTIVE

Renal transplantation has dramatically improved the survival rate of hemodialysis patients. However, with a growing proportion of marginal organs and improved immunosuppression, it is necessary to verify that the established allocation system, mostly based on human leukocyte antigen matching, still meets today's needs. The authors turn to machine-learning techniques to predict, from donor-recipient data, the estimated glomerular filtration rate (eGFR) of the recipient 1 year after transplantation.

DESIGN

The patient's eGFR was predicted using donor-recipient characteristics available at the time of transplantation. Donors' data were obtained from Eurotransplant's database, while recipients' details were retrieved from Charité Campus Virchow-Klinikum's database. A total of 707 renal transplantations from cadaveric donors were included.

MEASUREMENTS

Two separate datasets were created, taking features with <10% missing values for one and <50% missing values for the other. Four established regressors were run on both datasets, with and without feature selection.

RESULTS

The authors obtained a Pearson correlation coefficient between predicted and real eGFR (COR) of 0.48. The best model for the dataset was a Gaussian support vector machine with recursive feature elimination on the more inclusive dataset. All results are available at http://transplant.molgen.mpg.de/.

LIMITATIONS

For now, missing values in the data must be predicted and filled in. The performance is not as high as hoped, but the dataset seems to be the main cause.

CONCLUSIONS

Predicting the outcome is possible with the dataset at hand (COR=0.48). Valuable features include age and creatinine levels of the donor, as well as sex and weight of the recipient.

Single-center experience with third and fourth kidney transplants

Kidney retransplantation is often associated with a higher immunological risk than is primary renal transplantation. Faced with increasing organ shortage and growing waiting lists, results of kidney retransplantation are of particular interest. Fifty-six third and fourth kidney transplants were analyzed retrospectively. Parameters included patient and donor demographics, operative details, incidence of surgical, immunological and infectious complications and patient and graft survival. Patients receiving third kidney grafts had 1- and 5-year patient/graft survival rates of 97.4%/72.9% and 88.9%/53.6%, respectively. Episodes of acute rejection and delayed graft function were observed in 44% and 49% of these patients. Fourth kidney transplantation was associated with 1- and 2-year patient/graft survival rates of 84.8%/68.5% and 63.6%/47%, respectively. Acute rejection and delayed graft function occurred in 33% and in 60% of cases. Acceptable patient and graft survival may be achieved after third and fourth kidney transplantation. Graft losses in this sensitized population are mainly because of rejection. Profound immunosuppression may lead to major infectious problems.

Early steroid withdrawal in repeat kidney transplantation

BACKGROUND AND OBJECTIVES

Kidney re-transplantation (KRT) candidates are considered at high risk for graft failure. Most of these patients are kept on a chronic steroid maintenance (CSM) regimen. The safety of early steroid withdrawal (ESW) remains unanswered in KRT.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study was aimed at comparing the outcomes of ESW and CSM in KRT. Retrospective analysis of 113 KRT patients (ESW, n=59; CSM, n=54) was performed. All patients received rabbit anti-thymocyte globulin/steroid induction and were maintained on mycophenolate/tacrolimus (±steroids).

RESULTS

One- and 5-year patient survival for the ESW and the CSM group were not significantly different (98 versus 96% and 91 versus 88%, respectively; P=0.991). No significant difference was seen in the graft survival for both groups at 1 and 5 years (98 versus 93% and 80 versus 74%, respectively; P=0.779). Mean 1- and 5-year estimated GFR was not statistically different between the groups (P=0.773 and 0.790, respectively). The incidence of acute rejection at 1 year was 17 and 22% in ESW and CSM patients, respectively (P=0.635). Compared with the ESW group, patients in the CSM group were more likely to be hyperlipidemic (P=0.044), osteoporotic (P=0.010), post-transplant diabetics (P=0.051) and required more medications to control BP (P=0.004).

CONCLUSIONS

ESW seems to be a reasonable approach in KRT recipients because the short and intermediate patient survival, graft survival, and graft function is comparable to CSM immunosuppression.

Equivalent outcomes with primary and retransplantation in African-American deceased-donor renal allograft recipients

BACKGROUND

Graft survival following renal retransplantation has been inferior to that following primary allografting, particularly in African Americans (AAs) receiving deceased-donor (DD) kidneys.

METHODS

Among 166 AA DD renal allograft recipients transplanted from July 2001 through July 2007, we compared the outcomes of 26 (16%) receiving a second graft with those of 140 primary cases. All patients received either thymoglobulin (ATG) or an IL-2 receptor antagonist for induction, and were maintained on either tacrolimus or sirolimus + mycophenolate mofetil +/- prednisone.

RESULTS

When compared with primary transplants, regrafts received kidneys from older donors, were younger, more sensitized, more likely to receive ATG and to be maintained on prednisone, received more doses of ATG, and were less likely diabetic. There was no difference between primary and retransplant groups in overall patient or graft survival; incidence of acute rejection, CMV infection, BK nephropathy, or new-onset diabetes mellitus; and serum creatinine at 1 year.

CONCLUSION

AA renal allograft recipients can undergo a second DD transplant with intermediate-term outcomes comparable to that of a primary graft, despite the presence of multiple immunologic and non-immunologic high-risk factors, by extending the course of ATG induction and continuing prednisone therapy in the vast majority of cases.

Repeat renal allografts treated with sirolimus, cyclosporine, anti-thymocyte globulin induction and continuous steroids achieve similar immunosuppressive efficacy as primary transplants

OBJECTIVE

We sought to examine repeat versus primary renal transplantations using sirolimus-based regimens.

METHODS

We compared 98 repeat versus 200 matched primary recipients treated de novo with sirolimus plus cyclosporine. Every repeat case received polyclonal antibody induction and continuous steroids. Outcomes were evaluated over a mean five-year follow-up by univariate and multivariate techniques. Kaplan-Meier plots were analyzed with using log-rank statistics with significance at P < or = 0.05.

RESULTS

Significant differences in demographic features included greater panel reactive antibody (PRA), younger age, fewer HLA-mismatches and more pre-emptive repeat versus primary grafts. Neither graft and patient survivals, nor incidences of biopsy-proven acute rejection (BPAR), chronic vasculopathy or tubular atrophy/interstitial fibrosis among biopsies performed for cause were significantly different at 1 and 5 years. Younger recipients, better HLA matches and absence of diabetes promoted repeat graft survival; whereas older age, longer cold ischemia time and BPAR reduced primary transplant outcomes. Renal function was similar at 1, 3, 12, 24, 48 and 60 months.

CONCLUSION

At 5 years this sirolimus regimen achieved similar efficacy for repeat versus primary transplantations.

Rationale and criteria of eligibility for calcineurin inhibitor interruption following kidney transplantation

PURPOSE OF REVIEW

To summarize predictive low-risk parameters of renal allograft recipients for purposes of improving the initiation of calcineurin inhibitor withdrawal protocols.

RECENT FINDINGS

Clinical trials have demonstrated the potential global benefit of calcineurin inhibitor interruption protocols on graft survival despite being associated with an increased rate of acute rejection episodes, thus underlying a number of risk factors. Recent identification or confirmation of variables updating the list of parameters and molecular markers that can be used to predict graft outcome are described.

SUMMARY

The effect of calcineurin inhibitor withdrawal on long-term graft and recipient survival patterns is assessed in relation to the large number of calcineurin inhibitor-related side-effects. However, current protocols are based on empirical observations and there is a clear requirement for reliable parameters to define patient eligibility for calcineurin inhibitor weaning procedures. Here, we review biological, clinical and genetic parameters that can be used as predictive markers of long-term graft outcome and could serve as criteria for patient selection in calcineurin inhibitor weaning protocols.