The impact of slow graft function on graft outcome is comparable to delayed graft function in deceased donor kidney transplantation

Urinary Biomarkers for Cell Cycle Arrest TIMP-2 and IGFBP7 for Prediction of Graft Function Recovery after Kidney Transplantation

TIMP-2 and IGFBP7 have been identified and validated for the early detection of renal injury in critically ill patients, but data on recovery of allograft function after kidney transplantation (KTx) are scarce. In a prospective observational multicenter cohort study of renal transplant recipients, urinary [TIMP-2] × [IGFBP7] was evaluated daily from day 1 to 7 after KTx. Different stages of early graft function were defined: immediate graft function (IGF) (decrease ≥ 10% in serum creatinine (s-crea) within 24 h post KTx); slow graft function (SGF) (decrease in s-crea < 10% within 24 h post KTx); and delayed graft function (DGF) (any dialysis needed within the first week after KTx). A total of 186 patients were analyzed. [TIMP-2] × [IGFBP7] was significantly elevated as early as day 1 in patients with DGF compared to SGF and IGF. ROC analysis of [TIMP-2] × [IGFBP7] at day 1 post-transplant for event "Non-DGF" revealed a cut-off value of 0.9 (ng/mL)2/1000 with a sensitivity of 87% and a specificity of 71%. The positive predictive value for non-DGF was 93%. [TIMP-2] × [IGFBP7] measured at day 1 after KTx can predict early recovery of transplant function and is therefore a valuable biomarker for clinical decision making.

Identification of potential necroinflammation-associated necroptosis-related biomarkers for delayed graft function and renal allograft failure: a machine learning-based exploration in the framework of predictive, preventive, and personalized medicine

Delayed graft function (DGF) is one of the key post-operative challenges for a subset of kidney transplantation (KTx) patients. Graft survival is significantly lower in recipients who have experienced DGF than in those who have not. Assessing the risk of chronic graft injury, predicting graft rejection, providing personalized treatment, and improving graft survival are major strategies for predictive, preventive, and personalized medicine (PPPM/3PM) to promote the development of transplant medicine. However, since PPPM aims to accurately identify disease by integrating multiple omics, current methods to predict DGF and graft survival can still be improved. Renal ischemia/reperfusion injury (IRI) is a pathological process experienced by all KTx recipients that can result in varying occurrences of DGF, chronic rejection, and allograft failure depending on its severity. During this process, a necroinflammation-mediated necroptosis-dependent secondary wave of cell death significantly contributes to post-IRI tubular cell loss. In this article, we obtained the expression matrices and corresponding clinical data from the GEO database. Subsequently, nine differentially expressed necroinflammation-associated necroptosis-related genes (NiNRGs) were identified by correlation and differential expression analysis. The subtyping of post-KTx IRI samples relied on consensus clustering; the grouping of prognostic risks and the construction of predictive models for DGF (the area under the receiver operating characteristic curve (AUC) of the internal validation set and the external validation set were 0.730 and 0.773, respectively) and expected graft survival after a biopsy (the internal validation set's 1-year AUC: 0.770; 2-year AUC: 0.702; and 3-year AUC: 0.735) were based on the least absolute shrinkage and selection operator regression algorithms. The results of the immune infiltration analysis showed a higher infiltration abundance of myeloid immune cells, especially neutrophils, macrophages, and dendritic cells, in the cluster A subtype and prognostic high-risk groups. Therefore, in the framework of PPPM, this work provides a comprehensive exploration of the early expression landscape, related pathways, immune features, and prognostic impact of NiNRGs in post-KTx patients and assesses their capabilities as.predictors of post-KTx DGF and graft loss,targets of the vicious loop between regulated tubular cell necrosis and necroinflammation for targeted secondary and tertiary prevention, andreferences for personalized immunotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00320-w.

Clinical Outcomes of Transplanted Kidneys from Deceased Donors Using Different Generic Preservation Solutions

Background and Objectives: StoreProtect Plus® is a preserving solution for cold organ storage, with a composition identical to Institute Georges Lopez (IGL-1) solution. The aim of this single center study was to compare the clinical performance of StoreProtect Plus with the generic counterpart of University of Wisconsin preservation fluid, named SPS-1®. Materials and Methods: The clinical outcomes of 168 consecutive organs preserved with StoreProtect Plus solution and 167 organs preserved with SPS-1 solution were compared. During an 18-month post-transplant follow-up period, kidney graft function, the frequency of acute rejection, post-transplant diabetes, and infectious complications, as well as patient and graft survival were analyzed. Results: There was significantly more immediate graft function (IGF) (39.3 vs. 24.0%; p < 0.01) and less slow graft function (SGF) (38.7 vs. 51.5%; p < 0.05) in the StoreProtect Plus group in comparison with the SPS-1 group, whereas the occurrence of DGF was similar in both groups. Long-term kidney graft function was comparable. Multivariate regression analysis showed that the use of StoreProtect Plus vs. SPS-1 solution (rpartial = 0.217; p < 0.001) and the amount of residual diuresis (rpartial = 0.147; p < 0.001) independently increased the occurrence of IGF, whereas Scr > 1.5 mg/dL prior to organ procurement (rpartial = −0.198; p < 0.001), longer CIT (rpartial = −0.170; p < 0.01), and CVD donor death (rpartial = −0.214; p < 0.001) were associated with SGF. Conclusions: The higher occurrence of IGF was found in kidney transplant recipients whose organs were preserved using StoreProtect Plus solution as compared with SPS-1 solution. The two groups did not differ in kidney graft function, the frequency of post-transplant complications, as well as patient and graft survival.

ABO Blood Incompatibility Positively Affects Early Graft Function: Single-Center Retrospective Cohort Study

BACKGROUND

We investigated the association between ABO-incompatible (ABO-I) kidney transplantation and early graft function.

METHODS

We retrospectively analyzed 95 patients who underwent living donor kidney transplantation between May 2009 and July 2019. It included 61 ABO-compatible (ABO-C) and 34 ABO-I transplantations. We extracted data on immunologic profile, sex, age, cold ischemic time, type of immunosuppression, and graft function. Two definitions were used for slow graft function (SGF) as follows: postoperative day (POD) 3 serum creatinine level >3 mg/dL and estimated glomerular filtration rate (eGFR) <20 mL/min/1.73 m². Logistic regression analysis was performed to analyze the effect of ABO-I on the incidence of SGF.

RESULTS

The characteristics between the ABO-C and ABO-I were not different. ABO-I received rituximab and plasma exchange. Patients also received tacrolimus and mycophenolate mofetil for 2 weeks and prednisolone for 1 week before transplantation as preconditioning. Of the 95 study patients, 19 (20%) and 21 (22%) were identified with SGF according to POD 3 serum creatinine level or eGFR, respectively. Multivariable analysis revealed that ABO-I significantly reduced the incidence of SGF (odds ratio, 0.15; 95% confidence interval, 0.03-0.7; P = .02), and cold ischemic time >150 min increased the incidence of SGF (odds ratio, 6.5; 95% confidence interval, 1.7-25; P = .006). Similar results were identified in POD 3 eGFR. Inferior graft function in patients with SGF was identified up to 6 months after transplantation.

CONCLUSION

ABO-I reduces the incidence of SGF, which is associated with an inferior graft function up to 6 months.

Early graft function and intrarenal resistant index after kidney transplantation using Biolasol-A new solid organ preservation fluid

Biolasol is a newly developed preserving solution for cold organ storage prior to transplantation. To date, only animal model experiments results are available. The aim of this single-center analysis was to summarize the clinical experience concerning the early post-transplant course of kidney grafts preserved with Biolasol in comparison with other preservation solutions. Before transplantation, 173 kidney grafts were preserved using Biolasol and 240 organs with other solutions (University of Wisconsin-UW, Institute Georges Lopez-IGL-1, or StoreProtect Plus solutions). Early graft function was defined based on serum creatinine concentration at day 3 (<3 mg/dL-immediate graft function, IGF or >3 mg/dL-slow graft function, SGF) or the need of dialysis therapy during first post-operative week (delayed graft function, DGF). The analysis included intrarenal resistive indices measured by Doppler sonography early after transplantation and before discharge from the hospital. IGF was more frequent in patients with organs preserved with IGL-1 (33.5%) and StoreProtect Plus (38.8%) than Biolasol (18.5%), whereas there was no difference in the occurrence of DGF. Both initial and discharge median resistance index values were significantly higher in the Biolasol subgroup (0.77 and 0.75) than in all three other subgroups (P values for all comparisons <.001), also after 1:1 propensity score matching for baseline characteristics. Multiple logistic regression analysis based on the propensity score-matched cohort revealed that the use of Biolasol solution [OR 0.59 (0.35-0.98); P < .05] independently decreased the occurrence of IGF. In our single-center clinical experience, kidney preservation using Biolasol solution was associated with significantly higher intrarenal resistant index in comparison with other preservation fluids, as well as worse early graft function than in the IGL-1 and the StoreProtect Plus subgroups. Long-term follow-up is needed in order to assess the kidney graft and patient survival.

The combination of area under the curve and percentage change in estimated glomerular filtration rate predicts long-term outcome of kidney transplants

The development of surrogate markers for long-term outcomes of kidney transplant (KT) is a focus of attention. We examined the possibility of using a combination of the area under the curve of estimated glomerular filtration rate (eGFR) for 2 years (AUC_eGFR2yrs ) and percent change in eGFR between 1 and 2 years after KT (% change_eGFR1/2yr ) as a surrogate marker. We compared the predictive power of death-censored graft failure with various combinations. The combination of >2% vs ≤2% for % change_eGFR1/2yr and >1300 vs ≤1300 mL/min/month for AUC_eGFR2yr had the highest Harrell C-index (0.647; 95% confidence interval [95% CI], 0.604-0.690). The death-censored graft survival rate of the group with ≤2% change_eGFR1/2yr and ≤1300 mL/min/month AUC_eGFR2yr was significantly lower than those of other groups. The AUC/% change eGFR had comparable predictive power to the previously identified marker ≥30% decline in eGFR between years 1 and 3 after KT (≤-30% change_eGFR1/3yr ) (Harrell's C-index = 0.645 [95% CI 0.628-0.662] for ≤-30% change_eGFR1/3yr ). The proposed combination might be useful as a surrogate marker in KT trials because it requires a shorter surveillance period than the established marker while having comparable predictive power.

Effect of polyoma viremia on 3-year allograft kidney function

BACKGROUND

Polyoma viremia is associated with damage to renal tubular and urothelial cells. This may imply that a certain level of viremia, even cleared thereafter, could be associated with long-term renal dysfunction.

METHODS

We, retrospectively, analyzed 390 first renal transplants adult recipients (≥18 years) who were monitored for BK viremia in the first 12 months and evaluated estimated GFR (MDRD-4 equation) at 1 month and at the last follow-up (959 ± 392 days).

RESULTS

One hundred and ninety-nine patients (51%) developed at least one positive viremia: 105 (53%) low viremia (<10⁴  copies/mL), 36 (18%) high viremia (4 × 10⁴  > viremia ≥ 10⁴  copies/mL) and 58 (15%) viremia (≥4 × 10⁴  copies/mL) consistent with polyoma virus associated nephropathy (PyVAN). Out of these 58 patients, 24 (6%) developed bx-proven (SV40+) PyVAN and 34(8.7%) presumptive PyVAN (SV40-). Baseline characteristics, immunosuppression, KDRI, rejection episodes, etc., did not differ among groups but there were more deceased donors and ATG induction therapy in the high viremia group. At last follow-up, all patients in the low, high viremia and presumptive PyVAN (except 2) had cleared BK viremia. Bx-proven PyVAN led to 14 graft losses, 10 due to PyVAN. In the presumptive PyVAN there was only one graft loss registered as due to PyVAN. eGFR, at 1 month after KTx, did not differ among groups (51 ± 22 vs 48 ± 24 vs 45 ± 27 vs 43 ± 18 vs 46 ± 22 mL/min/1.73 m² ), for no, low and high viremia as well for presumptive PyVAN and bx-proven PyVAN groups, respectively. At the last follow-up, eGFR did not differ between the no, low, and high viremia compared to baseline and to each other but was statistically lower in the presumptive and bx-proven PyVAN (38 ± 15 and 17 ± 7 mL/min/1.73 m² ) either compared to baseline or to the other groups.

CONCLUSIONS

This study shows that low and high levels of BK viremia do not lead to GFR changes although very high viremia levels, compatible with presumptive or bx-proven PyVAN, even if cleared thereafter, lead to allograft damage and decreased GFR.

Association of Slow Graft Function with Long-Term Outcomes in Kidney Transplant Recipients

Background

Whether slow graft function (SGF) represents an intermediate phenotype between immediate graft function (IGF) and delayed graft function (DGF) in kidney transplant recipients is unknown.

Material/Methods

In a retrospective cohort analysis of 1,222 kidney transplant recipients, we classified patients as having IGF, SGF, and DGF using two different schemas. SGF was defined as serum creatinine (Cr) ≥3.0 mg/dL by postoperative day 5 in Schema 1, and in Schema 2, SGF was defined as Cr >1.5 mg/dL plus a creatinine reduction ratio <20% between postoperative days 1 and 3. A complementary log-log model was used to examine the association of graft function with graft survival and patient survival.

Results

Mean age of study patients was 51.5±13.3 years, 59.9% were male, and 66.7% were white. In Schema 1, SGF and DGF were associated with comparable increases in risk of graft failure compared to IGF (hazard ratio (HR) 1.46, 95% confidence intervals (CI) 1.02–2.10 for SGF and HR 1.56, CI 1.11–2.22 for IGF); estimates were similar for Schema 2 (HR 1.52, CI 1.05–2.20 for SGF and HR 1.54, CI 1.10–2.17 for IGF). However, for mortality, outcomes for SGF were similarly to IGF, both SGF and IGF were associated with lower risk relative to DGF (HR 0.54, CI 0.36–0.80 for SGF in Schema 1; HR 0.58, CI 0.39–0.85 for SGF in Schema 2).

Conclusions

These findings suggest that SGF may be a marker for graft failure but not for mortality, and SGF may therefore represent a phenotype separate from IGF and DGF.

Paired Analysis of Outcomes After Kidney Transplantation in Peritoneal and Hemodialysis Patients

BACKGROUND

The impact of dialysis modality before kidney transplantation (hemodialysis or peritoneal dialysis) on outcomes is not clear. In this study we retrospectively analyzed the impact of dialysis modality on posttransplant follow-up.

METHODS

To minimize donor bias, a paired kidney analysis was applied. One hundred thirty-three pairs of peritoneal dialysis (PD) and hemodialysis (HD) patients were transplanted at our center between 1994 and 2016. Those who received kidneys from the same donor were included in the study. HD patients were significantly older (44 vs 48 years), but the Charlson Comorbidity Index was similar (3.12 vs 3.46) in both groups. The groups did not differ significantly with respect to immunosuppressive protocols and number of mismatches (2.96 vs 2.95).

RESULTS

One-year patient (98% vs 96%) and graft (90% vs 93%) survival was similar in the PD and HD patient groups. The Kaplan-Meier curves of the patients and graft survival did not differ significantly. Delayed graft function (DGF) and acute rejection (AR) occurred significantly more often in the HD recipients. Graft vessel thrombosis resulting in graft loss occurred in 9 PD (6.7%) and 4 HD (3%) patients (P > .05). Serum creatinine concentration and estimated glomerular filtration rate (using the Modification of Diet in Renal Disease guidelines) showed no difference at 1 month, 1 year, and at final visit. On multivariate analysis, factors significantly associated with graft loss were graft vessel thrombosis, DGF, and graft function 1 month after transplantation. On univariate analysis, age, coronary heart disease, and graft loss were associated with death. Among these factors, only coronary heart disease (model 1) and graft loss were significant predictors of death on multivariate analysis.

CONCLUSION

The long-term outcome for renal transplantation is similar in patients with PD and HD. These groups differ in some aspects, however, such as susceptibility to vascular thrombosis in PD patients, and to DGF and AR in HD patients.

Peritransplant Soluble CD30 as a Risk Factor for Slow Kidney Allograft Function, Early Acute Rejection, Worse Long-Term Allograft Function, and Patients' Survival

BACKGROUND

We aimed to determine whether serum soluble CD30 (sCD30) could identify recipients at high risk for unfavorable early and late kidney transplant outcomes.

METHODS

Serum sCD30 was measured on the day of kidney transplantation and on the 4th day posttransplant. We assessed the value of these measurements in predicting delayed graft function, slow graft function (SGF), acute rejection (AR), pyelonephritis, decline of allograft function after 6 months, and graft and patient survival during 5 years of follow-up in 45 recipients.

RESULTS

We found the association between low pretransplant serum levels of sCD30 and SGF. The absence of significant decrease of sCD30 on the 4th day posttransplant was characteristic for SGF, early AR (the 8th day-6 months), late AR (>6 months), and early pyelonephritis (the 8th day-2 months). Lower pretransplant and posttransplant sCD30 predicted worse allograft function at 6 months and 2 years, respectively. Higher pretransplant sCD30 was associated with higher frequency of early AR, and worse patients' survival, but only in the recipients of deceased-donor graft. Pretransplant sCD30 also allowed to differentiate patients with early pyelonephritis and early AR.

CONCLUSIONS

Peritransplant sCD30 is useful in identifying patients at risk for unfavorable early and late transplant outcomes.

Kidney Donor Risk Index as the Predictor for the Short-term Clinical Outcomes After Kidney Transplant From Deceased Donor With Acute Kidney Injury

BACKGROUND

The Kidney Donor Risk Index (KDRI) scoring system for deceased donors has been widely introduced for postoperative evaluation of graft function. We analyzed the usefulness of the KDRI in deceased donors with acute kidney injury (AKI).

METHODS

Forty-nine recipients from deceased donors with AKI between January 2009 and December 2014 were reviewed retrospectively. Data collected from donor medical records included age, height, weight, hypertension or diabetes history, cause of death, serum creatinine (sCr), and donation after cardiac death. Graft function data including sCr, estimated glomerular filtration rate (eGFR), and acute rejection episodes were monitored for 1 year. Correlations between KDRI score and factors indicating graft function were analyzed. A cutoff value for KDRI score was calculated using a receiver operating characteristic (ROC) curve for significant graft function.

RESULTS

The mean ages of donors and recipients were 46.81 ± 13.13 and 47.69 ± 11.43, respectively. The mean KDRI score was 1.24 ± 0.40. Univariable analysis of KDRI score and factors indicating graft function indicated that sCr at 6 to 12 months, eGFR at 1 year, and slow graft function (SGF) had statistical significance. The ROC curve of KDRI score for SGF showed an optimal cutoff value of 1.20, with sensitivity of 69.2% and specificity of 69.4% (area under the curve = 0.75) in deceased donors with AKI.

CONCLUSIONS

KDRI score in deceased donors with AKI was correlated with postoperative graft values including eGFR and SGF. KDRI could be used as a predictor for the short-term clinical outcome after kidney transplant from deceased donor with AKI.